Uses Of Wind Energy In Rural Areas

Sharon asks…

Could anyone help me do a project by giving info on river valley projects of india?

location,power generated,states,irrigated areas

Windmill Farms answers:

Energy is critical in developing countries not only for economic growth but also for social development and human welfare. Even though over 4 billion people live in the developing countries which is more than three fourths of the world population; nevertheless they use less than one third of the world’s energy, with per capita levels one sixth that of the highly industrialist countries. Over two billion people are yet deprived of electrical energy. Driven by rising populations, expanding economies, energy intensive industries, urbanisation and a quest for modernisation and improved quality of life; energy use in the developing world has doubled in the last two decades and further expected to double again in an even shorter time span of the next fifteen years. Indian per capita consumption of electricity continues to be extremely low around 350 kwh per annum. Another striking fact remains that only one third electric supply is consumed in the rural areas despite three fourths of Indian population living in rural areas. While 86% of the villages have access to electricity only about 30% of the rural households are able to use electric power. About 80,000 villages remains yet to be electrified inspite of the highest priority given to rural electrification in India. Most of these villages are located in far flung and remote areas, with very low load densities requiring heavy investment in electrifying these villages. In rural areas energy for cooking, lighting, water pumping, agro and rural industry and other productive activities can be effectively provided through locally available renewable energy sources. In remote areas where transmission of grid power is totally uneconomical, off grid electrification can be undertaken through renewable energy systems such as small and medium hydro schemes besides solar photovoltaic. Appropriate electricity requirements can also be met by hybrid systems integrating two or more sources, in conjunction with storage. It is estimated that only another 8% of Indian villages can be electrified by extension of the grid thus leaving 35,000 or 6% of the villages yet to receive electric energy.

The detailed power planning studies carried by Central Electricity Authority (CEA) have convinced that the share of hydro power in the overall installed generated capacity in the country should be at least about 40% to ensure optimum utilisation of natural and financial resources for electric power generation. Thus the accelerated hydro power generation is unavoidable preposition when about 75% of the hydro potential of 84,000 MW still remains to be harnessed. The paper highlights that the integrated development of hydro projects and rural development with a focus on environmental management can be duly taken care of through the clearly laid down strategies and policies. Indian power development needs priority correction by substantial addition of hydro power generation capacity together with blending of the catchment area treatment, watershed development and water harvesting practices in the mountain and hilly terrains of the country.

India is endowed with primary energy resources in various forms – water, fossil fuels (coal, lignite, oil and natural gas)and nuclear fuel and will serve as major sources for power generation. Non-conventional and renewable sources of energy such as fuelwood, biomass, tidal, solar, wind and geothermal energy are also available but they are in preliminary stages of development. These resources are not evenly distributed over various regions/states in the country. Over the period of next fifteen years (upto 2006-07) it is estimated that hydro power as a renewable source and fossil fuels i.e. Coal and lignite will remain main sources for power generation in India duly supported by natural gas to some extent. Share of nuclear power is also expected to increase appreciably in future.

The economics of power generation through non renewable sources of power -fossil fuels- changes with the exploitations of every successive ounce of such fuels. Renewable sources -hydro, solar, wind, tidal etc in this background offer a lucrative option in long run. With the status of technologies developed for exploitations of these renewable sources of energy, so far, hydro power appears to offer major attraction and deserves to be given highest preference amongst various options available. It is the only renewable form of primary energy with substantial unexploited potential with number of other major technical and economic advantages by virtue of non polluting nature, high conversion efficiency, flexibility in operation, relatively lower cost of generation, operation and maintenance, longer life of equipment etc. At the same time it has to be appreciated that (a) bulk of the unexploited hydro resources are in difficult/inaccessible terrains in the Northern and North Eastern Regions and (b) hydro projects generally entail longer gestation periods. Central Electricity Authority has been consciously keeping these aspects in view while carrying out studies for evolving long term perspective National Power Plans.

The Indian growth in power availability has not been able to keep pace with the growth in power demand. Peaking Power deficit of the order of 28.3% and energy shortage aggregating to 9.2% were experienced during 1995-96. As per the projections made by the 15th Electric power survey, the requirement and peak demand requirement which stood at 3,89,721 MU and 60,981 MW during 1995-96 are likely to increase to 5,69,650 MU and 95,757 MW respectively by the end of the 9th Plan (2001-02). Indicative forecasts for energy requirements and peak power demand by the end of the 10th and 11th Plans are of 7,81,863 MU/1,30,944 MW and 10,58,440 MU /1,76,647 MW respectively. Thus the requirement for electrical energy and peaking power in the country is likely to go up by over 170% and over 190% respectively in the next 15 years.

The basic objective of the long term plan should be to meet the above mentioned rapid rise in power demand with reasonable levels of reliability and at the lowest possible cost to the consumer. In drawing up such a plan, the following factors merit special consideration:

Acceptable levels of reliability;
Options for power development including their technological, economic, environmental and ecological aspects as well as the global trend in fuel availability and pricing of fuel.
Demand and supply side management options; and
Policies of the Government.
The Central Electricity Authority estimates the growth in demand for power through Electric Power Survey Committee (EPS). So far 15 such EPS Committee have brought out their reports. The projections made by the 15th EPS are currently in use for various Power Planning Studies. The generating capacity requirements on long terms basis are worked out using sophisticated computer Models. Recently CEA has procured Electric Generation Expansion System (EGEAS) version 9 Model developed by Electric Power Research Institute (EPRI), USA and Integrated System Planning (ISPLAN) Model developed by M/s International Development and Energy Associates (IDEA) UK. So far CEA had brought out four National Power Plans using the various computer Models.

The immediate next Five Year Plan is prepared by the Government keeping in view the recommendations of the working group on Power set up for the plan under formation, Task Force Reports, Planning Commission Reports and Government Policies on Power Development. One of the key factors is financial resource available for power development in public sector and the private sector participation in creating additional facilities. So far CEA had brought out four National Power Plans. The first National Power Plan was issued in 1983 and exhaustive computer studies were made using WASP-III Electric Generating capacity Expansion Planning. This model was developed by the International Atomic Energy Agency (IAEA) Vienna. In the first National Power Plan formulated by CEA in 1983, the desirable hydro thermal mix by the end of then 8th Plan (1994-95) was proposed as 40:60 taking into account the committed capacity, availability of new hydro schemes ripe for capacity addition, the other generation options available, the targeted system reliability level, pattern of power demand in various power regions of the country, etc. Prevailing at that time. The matter was again reviewed at the time of preparation of the second National Power Plan and taking note of the status including the difficulties being experienced then in putting through the hydel schemes,. It was proposed that an all India hydro thermal mix of 34:66 may be attempted by the end of then 9th Plan (1999-2000). The National Power Plan lays special emphasis on accelerated development of hydro power to include as many hydro candidate projects as possible in the Planning scenario without adversely affecting the utilisation of the non hydro facilities already in place or in pipe line.

Subsequent National Power Plans were prepared using EGEAS and ISPLAN computer Models. According to Fourth National Power Plan, the country would need addition of over 1,50,000 MW thereby raising the installed capacity in the country to about 2,38,000 MW to meet peak demand of 1,76,647 MW and energy requirement of 1058 Billion Units by the end of 11th Plan (2011-12). The impact of accelerating hydro power development examined in the report indicated that the accelerating the present pace of hydro development to add 58,000 MW over the next 15 years would result in a saving of 9,000 MW in terms of new thermal capacity. Studies had also revealed that to sustain the massive thermal power development, indigenous coal production has to be increased.

The report concludes that there is a need to accelerate nuclear power development programme to at least 10,000 MW capacity by the end of 11th Plan and to reduce transmission and distribution losses to a level of 15% from the present level of 21% and to continue renovation and modernisation programme of existing hydro and thermal generating units in future as well along with suitable life extension programme and to ensure formulation of National Power Grid by the end of 11th Plan to achieve tangible savings in additional capacity requirements besides benefits from non-conventional sources of energy to the extent possible to bridge the demand supply gap. This may be specially suitable in remote locations poorly connected to grid supply. The environmental and resettlement & rehabilitation issue should be addressed at the project formulation stage to reduce overall gestation period of the power projects. Strong centralised coordination in planning at the national and regional levels is required in order to ensure sustainable and optimal power development.The total installed capacity of hydro power plants at the end of 7th Plan(March 90) was around 18,300 MW-29% of the total capacity. Only 881 MW of hydro capacity was added during the two annual plans 1990-92.

The total installed capacity of hydro power plants in the country at the end of 8th plan (March 97) was 21,516 MW out of total installed capacity of 84,904 MW. This shows that share of hydro capacity has declined from 29% at the end of 7th Plan to 25% at the end of 8th Plan. The hydro capacity addition during two Annual Plans between 7th and 8th Plans (90-92) were only 881 MW. The Task Force on 9th Plan has recommended capacity additions of 10,515 MW from the hydro projects during the 9th Plan period. Out of this 3,430 MW has been envisaged in the Central Sector, 6,295 MW in the State Sector and 790 MW in the Private Sector. The total additional capacity recommended for benefits during 9th Plan is 52310.2 MW. The efforts for the hydro electric development, during fifties and sixties had a meaningful support from surveys conducted from time to time of the hydro electric resources of the country. The first systematic survey was conducted in early fifties, which was based on evolving specifies schemes in the river basins; which were considered technically feasible and economically viable. For diverse reasons this discreet methodology has been chosen in preference to the general practice of estimating the exploitable potential from an assessment of theoretical potential. According to this survey, 260 possible schemes were identified on different rivers, corresponding to a capacity of about 42 million KW at 60% load factor. Certain river basins in the Himalayan river systems, specifically in the Upper reaches, were left out due to topographical reasons. The assessment had been revised in the recent survey conducted by the CEA taking into account the technologies and information in regard to the economic viability. The economics of power generation also has, in the recent past, undergone a marked change with the energy becoming more and more scarce and costly. Hence CEA undertook an exhaustive and comprehensive assessment exercise taking into account, the latest technological development and availability of much larger and reliable data etc. As a result of this study, the country is now assessed to possess hydro resources of the order of 85,000 MW at 60% load factor equivalent to an annual energy generation of 450 Twh.

It is well recognised that hydro power constitutes the cheapest source of power generation in India even after the recent enormous increases in the cost of the equipment and the implementation of civil works. The economic advantages of hydro power has been enhanced in the recent years with the steep increases in the energy costs from fossil fuel and the rapidly approaching limits to the exploitable resources of such fuels. While the importance of hydro electric development for economic and reliable supply of power is recognised, the dismal share of hydro electric plants in the overall installed generating capacity has been due to the following main factors:-

Uneven distribution of hydro electric resources, among the political divisions.
Concentration of hydro resources in the states, having neither demand for power nor capability for large hydro development.
Environmental constraints in terms of deforestation, submergence and rehabilitation.
Inter-state and inter-regional disputes.
Inadequate emphasis during investigation and initial states of planning.
Geological uncertainties leading to slowing down of the civil works.
Socio economic impediments due to far flungness of the sites from the urban centres.
Attitudinal impediments in terms of choices for shorter gestation schemes.
Financial constraints.
The controversy concerning the large versus small dams, fear of earthquakes, silting of reservoirs, submergence of forests, extinction of “rare” flora and fauna, submergence of ancient cultural heritage, the prospect of outbreak of diseases like malaria and dislocation of population are often cited as reasons for abandoning the large hydro projects. These aspects have been briefly discussed in the following paragraphs. Basic facts on comparative evaporation, submergence of land, seismic effects and cost/benefit aspects of large-versus-small dams, based on significant rigorous studies, carried out by reputed agencies and experts in their respective fields; have been reported here.

4.1 Seismic Impacts
It is to be pointed out that the dams designed by modern techniques and built according to the latest specifications have considerable reserve strength to withstand severe earthquakes. Because of the application of such advanced techniques in both the design and execution, large dams have larger earthquake resistance capability. On the other hand, the small or medium-size hydraulic structures constructed without the state- of-art techniques remain susceptible to much smaller seismic intensity. There is very little proof that can be gathered on the statement that impounding of water in large reservoirs induces seismicity. The fact remains, and this has been adequately documented, that even when such seismic shocks occur, such shocks are much less to the natural tectonic intensity which the dams are designed to withstand. Such large dams as Tarbela, Bhakra, Ramganga and Pandoh are located in the Himalayan region and there is little to prove that these dams have caused RIS or any increase in seismic activity in the area following their construction. As demonstrated elaborately by Dr. Jai Krishna, President International Society of Earthquake Engg. (ISEE), tall dams in seismic environments are found much more resistant to earthquakes and they are significantly economical as opposed to the dams of lesser height in same areas. Director of Wadia Institute of Himalayan Geology, Prof. Vikram C. Thakur, has concluded from his studies that the construction of large dams in the outer Himalayan zone does not pose seismic problems and serious flaws exist in the seismic-gap theory. Prof Thakur points out that the basic geological data, now available for all major parts of the Himalayas, shows that large structures can be safely planned and constructed through delineation of active faults. Present design of dams undergo a detailed and extensive process of field investigations, analytical and laboratory studies, testing of construction materials. Such processes are undertaken in association with an established and wide network of seismological observatories. At every step, adequate care is taken to maintain the desired quality control. Procedures are followed meticulously in the areas of field investigation, design and construction by qualified personnel and reputed independent technical advisory committee of experts.

4.2 Effects On Wildlife, Monuments And Forests
The most-frequented tourist and scenic places in India such as the Brindaban and Shalimar gardens, Ukai and Periyar wildlife resorts, Dhyaneshwar and Ramganga udyans, Kalindi- Kunj, Matatila Lake etc. Are direct by-products of various river valley projects. Rare species of birds flock to these sanctuaries which have further helped to diversify wildlife significantly. This is most visible in and around Rihand, Matatila and Ramganaga dams where the availability of water all-year round has flourished and diversified the bird species. Historical and cultural monuments have been successfully relocated from various dam sites giving these a greater lease of life. Such efforts met with great success in Nagarjunsagar, Bargi and Srisailam projects in India. Jyotirling temple has been preserved in the planning of the Omkareshwar dam and expenses incurred in improving the approach roads and bridges to the aforesaid temple are a necessary and integral part of the project. One other point worth making and that is the loss of forests due to felling of trees to meet the fuelwood requirement of the poor, particularly during the harsh winter days in the mountains. A small amount of hydropower, if made available to the hill people, would reduce such losses significantly. Of the reported 3 % loss of the forest area due to river valley projects ( Forest Survey of India Report 1991), much of it occur in areas which are often described as forests but do not have the required forest cover and therefore, cannot be described as forest land.

4.3 Rehabilitation
The physical, emotional and financial sufferings of displaced persons caused by the construction of river valley projects cannot be overstated and should be a prime concern for all. Present day trend is to provide liberal compensation, adequate amenities, land and employment to the displaced population. This has been exhibited in the Sardar Sarovar Project, Tehri Dam and such large water projects. Moreover, attractive provisions made in the National Rehabilitation Policy for water resources projects (approved by the National Water Board) should be implemented in toto. Environmental, social and voluntary agencies should make efforts to come up with models of rehabilitation pattern and also cooperate in the healthy execution of viable and highly beneficial multipurpose projects. These agencies must keep in mind the thirst, hunger and employment needs of millions of our countrymen who should be best served through these large water management projects. Successful execution of river valley projects would remove the perpetual economic, educational and primary health-related backwardness prevalent among the tribals, hill people and those residing in the underdeveloped regions of the country. The issue of rehabilitating the displaced people and providing them with long-term meaningful employment out of large water projects is crucial for setting up industrial facilities and power generation stations, building houses for the mass and other vital activities. A planned approach must be adopted to rehabilitate displaced people, no matter what sectoral activities caused such displacements rather than indulging in furious battles with the sole purpose of shutting down the hydropower projects only. In addition, the employment aspect in choosing the mode of construction should be looked into. Choice of masonry dams over concrete dams lead to larger employment at the construction site. Setting up industrial training institutes and commercial trade training centres; use of donkeys, mules, elephants and bullock carts in the handling of bulky construction materials; developing skilled technicians and project workers engaged in large water projects are some of the healthy practices often adopted in India. The added advantage of adopting such practices is that it helps to bring the tribal and poor rural folks to the national mainstream.

4.4. Climatic Changes
The micro-climatic changes caused by the construction of large reservoirs are insignificant. However, moderating changes take place in temperature and humidity which are mostly beneficial. For instance, intense heat wave conditions that used to prevail in the Rajasthan deserts and Rihand dam areas have subsided significantly following the construction of IGNP and Rihand dam.

It has been established that shallow storage causes proportionately greater loss of land area due to submergence. Shallower storage also means greater evaporation as per studies conducted in many river valleys by reputed scientific agencies. In addition, it is difficult to find large number of alternative sites for medium projects even if such an alternative is preferred over deeper storage. Moreover, small and medium projects have to be constructed generally in the upper reaches of hills, which cause substantial loss of valuable forests. Construction of large dams, on the other hand, in the foothills involves submergence of large areas of cultivated lands per unit of storage. This shortcoming, however, is compensated many ways in multi-purpose projects such as through use of canals. For this reason small and medium hydel projects are not only costlier than the large projects but they also submerge larger land areas for the equal amount of storage and in addition, they have increased evaporation losses. Steep gradients in the river beds, large rolling boulders and sedimentation problems further limit the efficacy of small and medium hydel projects. This became particularly evident in case of Ichhari and Maneri Bhali dams (60 metres and 39 metres height respectively), both being run of the river projects. These were filled up to crest by sedimentation during construction itself as planned. It is evident therefore that large water storage projects are surely better alternatives wherever the parameters such as the volume of water flow, geological and topographical considerations and regional requirements can be satisfied and it can be established that such projects would integrate the environmental, socio-economic and engineering aspects as well. It is also known from historical records that the dynamic nature of environmental effects, which seem adverse to the environment at the time of construction, generally tend to stabilise and become less unfavourable. This has become evident from case studies made for the Aswan, Ramganga, Indira Nehar Project, BSL, Bhakra and Hirakud, among other projects.

The progress of most of the projects has been slow mainly due to low priority accorded to the projects, by the states due to inadequacy of funds year after year, delays in land acquisition, getting forest and environment clearances, identification of non forest land for compensatory afforestation and resettlement & rehabilitation problems etc. Since many hydro power projects could not be commissioned within the projected time frame in the past, it sent erroneous signals to the affect that hydro power stations take very long time for completion. This perception further discouraged allocation of funds to hydro projects and most of the states preferred to take up the thermal or gas/liquid fuel based projects with comparatively lower gestation periods to secure benefits in the shorter time frame to meet the rapidly increasing demand for power. This is despite the fact that the development of thermal power plants, in turn, puts added pressure and burden with related additional costs on development of coal mines and rail transportation infrastructure not directly reflected in the project costs, If these costs on development of connected infrastructure are also taken into account, the economic of hydro power may further improve. It is therefore necessary that apprehensions that hydro projects involve higher investments need to be properly dispelled.

Although over 245 proposals aggregating to over 93,000 MW capacity for various types of power projects are reported to have been received from private investors, very few serious proposals have been received for taking up hydel schemes. Perhaps investment and time involved in making a precise estimate of costs, based on not so thorough investigations made so far for these projects, prolonged time taken for acquisition of land, forest and environment clearances, resettlement problems etc. Could be some of the factors discouraging the private entrepreneurs from investing in hydel projects in a big way. In a number of instances, inadequate investigations of the project formulation had resulted in geological surprises leading to long delays in completion of the projects and the resultant cost over runs. Private investors cannot afford to take such risks. Sometime ago it was felt that with the further liberalisation of government guidelines, more entrepreneurs would show interest, but this has not happened so far despite further liberalisation of incentives on hydro projects.

The State Govts. Should also help the project authorities by themselves getting all requisite clearances, acquiring the land and building infrastructure, as a part of their contribution to the development of hydel resources. This would enable the private investors to take up the construction of the project without much loss of time. The cost incurred could be debited to the cost of the project and recovered from the private promoter. In order to tap the vast hydel resources in North Eastern Region, a special incentive by way of additional return on Equity could also be considered.

Availability of adequate financial resources is the foremost requirement for development of hydro resources. Way and means have to be found out to raise additional resources for hydro development. The states should take up construction of only such projects for which it would be able to provide full funds on a year to year basis till the commissioning of the projects. All other projects could be taken up with the assistance of private promoters. Adoption of new design and construction technologies and use of modern construction equipment available elsewhere in the world could help in reducing the construction period of hydro projects. If necessary, technical assistance of reputed and competent foreign companies could also be secured for this purpose. Leasing arrangements for high cost construction equipment could also be considered as it may not be feasible for project authorities to obtain such equipment individually.

As per Task Report on 9th Plan, there is a possibility of adding about 10,500 MW of hydro capacity out of 52,000 MW additional overall planned capacity. Only 800 MW of capacity is expected through private sector route. An investment of around Rs.50,000 to 60,000 crores may be required in central and state sectors for balance capacity addition. This kind of money would be difficult to comprehend from the Plan resources under the existing resources scenario. Some of the avenues that could be considered to raise the financial resources for hydro development are:-

Earmarking adequate plan funds for hydro development.
Joint ventures backed by financial institutions for construction of hydel projects.
World Bank & other International agencies assistance for hydro power projects.

There is no denial that electrical energy being the most preferred form of energy is needed by every country for improving the quality of life of its people. There is also no doubt that India should utilise the hydro power resources to the last drop of water. No doubt lessons learnt by others must be utilised in harnessing this resource but their decision to utilise water resources should not be influenced merely by demonstration effect. It is necessary that hydro power projects which involve large storages, interstate aspects, international river systems, pumped storage projects and multi-purpose projects should continue to be undertaken largely in the public sector. The central agencies should preferably be entrusted with the investigation, detailed planning, designs and execution of interstate hydro electric projects. Most of the untapped hydro potential remains in North Eastern and Northern Regions of India wherein the geological and engineering problems are to be faced due to young Himalayan ranges. India has initiated formulation of special development programme for the North Eastern Region including hydro development as its major component. To face the financial resource crunch, local financial institutions should be encouraged to finance hydro projects right from the stage of investigations together with earmarking most of the bilateral and multilateral funding for hydro projects. It becomes evident that the benefits accrued from large river valley projects are so immense that they substantially outweigh the costs of immediate human and environmental disruptions. On the other hand, long-term adverse effects of not utilising the water resources would be catastrophic due to recurrence of floods, droughts and the resulting unemployment will further the backwardness within the people.

Donald asks…

physics project about Renewable energy resources?

I was given this project about renewable energy where i have to choose one the following energies: solar, wind, water or biomass. I was thinking that the most chosen will be the solar and wind and water so i decided to use biomass. Now i have to answer the following questions:
Where does the energu come from?
How is the energy captured or produced?
What technology (devices or machinery) is used? Briefly explain how it works.
Discuss the advantages and disadvantages of the energy resources.

Can you please give me some information about each or at least just the most important points. Project must be about 4-6 pages and i m going to use powerpoint.

Windmill Farms answers:

Biomass is the excreta/dead remains of living things.

There are projects in some countries (notably India) called biogas plants. Dead remains and stools of animals are compressed in a machine by layering them on top of each other. Anaerobic thrive in them and methane is released through a pipeline, which can be used for household purposes.

The main and obvious advantage is that biomass is renewable. Also, after a one-time setup, the maintenance for this project is minimal. All you need to do is to add the wastes in to the system.

A disadvantage is that a single household does not generally produce enough waste to run an entire plant by itself. This problem is usually overcome by setting up community plants among 10-15 households. But again, this can give rise to management issues.
Also, this cannot be used in major cities and metropolises because their drainage system will need to be overhauled for this. But it is quite an effective system for rural areas, remote villages and ranches, where there is plenty of cattle waste, along with human excreta.

Mark asks…

Wind turbine placement?

I live in a rural area and we have two blue Harvestor grain silos. One has a 25 foot diameter and is 90 feet tall and the other is 4 feet from it with a 20 foot diameter and is 70 feet tall. I was wondering if it would be possible to mount a wind turbine on top of the taller one. I don’t know much about turbulence though, if there would be too much? Or how high it would have to be off to clear the turbulence? this is my first try at it, I was going to try a treadmill motor, something small.

Windmill Farms answers:

Hi Matthew. I have actually seen two silos with turbines on top. The main concern about turbulence is not with the silo, it has more to do with the terrain around it. Are there any trees or other structures that extend above the top of the silo that are within 200 feet of the silo? If the top of the silo has good exposure to winds, then it is probably a good place for the turbine. The other question to answer is whether or not the silo is in good structural condition. A home sized turbine will not put much force on the silo when it is operating, but there will be some force, and vibration. If the silo is masonry, meaning made from stone and mortar, are most of the mortar joints still good, or are there lots of missing spaces between the bricks?

I don’t know where you live, but if you want to learn more about this, I would suggest two things first. First, get a subscription to Home Power Magazine, the only periodical that really gets into the nuts and bolts of this technology. It is only about $25 a year, but they have articles explaining wind turbines, solar panels, inverters, batteries, and so on. Some issues even take all he commercially made turbines and list them with all the specs and other features, making it easy to select the one you want. If you subscribe, you can go to their website online and use their search engine to look for articles in the past that might help you out. Also go to the websites below, and check out the library for books. I’ll list one, if you can’t find it, just look for other books by that author, or on that subject matter.

The second thing to do is get to one of the energy fairs listed in the calendar section of Home Power, they are held all over the globe. The best and biggest one is in Wisconsin each June, but almost every state hosts one each year now. We went to one 12 years ago, and now our home is completely powered by the wind and sun, it was very informative. Take care Matthew, Rudydoo

Thomas asks…

How much energy would I save if I bought a solar panel?

Windmill Farms answers:

If you live in urban areas, or on the grid in rural areas and are thinking of putting up panels the last time I got quotes they were for 15-watts a square foot of area. That means if you put up 1,000 sq.ft. You get 15-kilowatt-hours of power per hour of full sun.

If you count on full sun output for 2-3 hours a day, take your average daily use in kilowatt-hours from your electric bill and divide back to get how many square feet you need to supply your house in 2.5 hours. Then consider the lot location, latitude, climate and all to figure things from there.

Then double that to pay the bills if you can (how many square feet face the sun well enough to use, etc.). This means you make money after the initial capital expense is paid off which doesn’t take long. For where there are restrictions against large panels there are cells made in what looks like roofing tiles; 1,000 square feet of panel in Seattle paid off in about 7 years.

What this means is that overall you are turning your roof into a small electric generation station tied to the grid so it adds to the power available for where it’s needed.

Not only will you save all the energy you use, you’d make more for others to use most days. Most homes use > 50-kilowatt-hours a day, but consider other things as well so it’s all installed at the same time to keep costs down.

If millions of people used panels, the existing grid can handle surges better, so, less likely to have a blackout or brownout during the summer for example. Panels are hard to get immediately, worldwide demand is high, Europe and Asia are installing a lot of them.

Improving your home’s insulation pays, so does putting up barriers to cold winds, improving solar gain on rooms where you can. Keep thinking about how your home either gets too cold or too hot. Lattice screens and awnings reduce solar gain where it’s too hot from too much sun. Work with what you have to reduce power needs, doesn’t take a lot to make a big difference at most sites.

Paul asks…

If wind turbines are to be the environmental cure all why are environmentalist opposed to them being built?

Windmill Farms answers:

It is not “all environmentalists” and it is not “all wind turbines” The story you linked actually gave a short summary of the beef Earth First has with that particular project.

Any energy source will have proponets and detractors. These groups will not always be split in predictable ways. Environmentalists are somewhat split on windpower just as they are on nuclear power. Likewise, many conservative soccer-moms would be split on turbines if they understood what they do for birds.

As we progress into new energy sources, new solutions will be developed for new problems. The problem at hand for wind turbines is damage to eco systems (and especially to birds if they are build in the birds’ flight paths). Many of the most infuential environmentalists — and many of the people most concerned with the eco system around Kibby Mountain are outdoorsmen and hunters, not the tree-hugging, smoke-pot-with-squirrells hippies that some people think of when they think of environmentalists.

To say all environmentalists are opposed to wind power is a bit like saying everyone who drives is in favor of gulf birds being covered in oil. Nothing is pure black and white. Environmentalism means living in a way that allows the environment that we love to continue to be something we love, to protect the outdoors. (and again, the people who get the most use of our protected wilderness areas are rural and suburban conservatives: hunters, Boy Scouts, etc).

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Wind Energy Facts

Michael asks…

provide facts and figures&analyse the opportunities and challenges that wind energy companies face in setting?

what are type of challenges are needed for wind farms in india for setting them up in india?

Windmill Farms answers:

The primary factor that I’m aware of for wind farms to be economically feasible is that you need an area that has a constant, average wind speed of 12 mph. The next challenge is how far is this area from the population center that you’re trying to supply, and do you have the means of constructing the transmission lines that are then required.

I would think that the northern parts of India, the sub-Himalayan areas, would be ideal, but how far would the power then have to be transmitted for use.

Daniel asks…

Is wind energy expensive and is it efficient?

Also what is the difference between wind power and wind energy?

Windmill Farms answers:

To start, wind energy is simply the energy stored in wind due to it’s kinetic motion. Power is a rate of energy (units of energy per unit of time, just like speed is units of distance per unit of time) so wind power is the rate at which energy is delivered by the wind.

Wind energy is among the less expensive of the renewable energy sources but the problem with assigning a cost to wind energy is it’s reliability. For example say it costs $1 million to build a 2MW (Mega-Watt) wind turbine. You might be tempted to say that wind costs $1 million per 2MW or $500000 per Mega-Watt but this isn’t really accurate because if the wind isn’t blowing, the turbine isn’t producing 2MW. Even if the wind is blowing but not very strong, the turbine doesn’t produce a full 2MW, it might only produce 1MW on some says.

For this reason, wind power has a low reliability and it’s difficult to put a price on this. Let’s imagine tha the $1 million wind turbine in the previous example powers a small town. The residents probably won’t want to have no power in the middle of winter of there is no wind so they buy a small natural gas power plant for $200 000 to generate power when there is no wind. Is the cost of generating wind from the turbine really only $1 million? After all we needed to spend an extra $200 000 that we wouldn’t have spend otherwise if we had just powered the town with coal or natural gas. In fact we could have just powered the town with the natural gas plant for $200 000 instead of getting the wind turbine in the first place.

Basically the cost of wind isn’t too expensive when you only consider the cost and maintenance of the turbine but when you consider the cost of backing it up with more reliable sources, it starts to become much more expensive. The fact that it doesn’t output power all the time makes it inefficient if you look at it in terms of what it could produce and what it actually produces on average.

Susan asks…

disadvantages of wind turbines/energy?

where can i find evidence stating that wind-produced energy is inefficient, that wind turbines are dangerous, etc?

please do not leave me information about why wind energy is, in fact, cost-effective in the long term or why the rumor of it killing birds is BS, etc. i need this information for a debate case for school; please only leave sources that can help me. (i’ve asked similar questions in the past, and received two answers, both giving me information proving the exact opposite of what i am asking for)

and due to strict resources guidelines, i cannot use evidence from blogs or wikepidea, so please do not leave sources leading to these places. thanks! :)

Windmill Farms answers:

The problem is that aside from the whole bird thing… Wind energy actually doesn’t really have many negatives.
Other than noise, endangering wildlife, and being “eyesores”, wind energy is generally really beneficial. I know that this doesn’t help you all that much, but I think these are the only true negatives to it.


I don’t know if this website will help or not, but it talks about how wind energy is more expensive than other sources of energy.

Ken asks…

alternate energy: wind?

what are the pros and cons of wind turbines to produce energy? name 3 pros and 3 cons.

Windmill Farms answers:

Is it really worth it to build wind turbines? What are the pros and cons? We’ll discuss these questions in this article.

In short: resounding yes. Many are against wind turbines and wind farm building and I have to admit they have a few good reasons other than the childish “I don’t like the look of wind mills in the countryside”. Well, I don’t like that the Arctic is getting smaller and smaller every day, and the fact that maybe my children won’t be able to experience the world as it is today. Letting go of the untouched view is a small sacrifice in exchange for nothing less than the whole future of the Earth.

Other than the “threat” to the panorama there are a few reasons why one wouldn’t choose wind turbines over regular electricity generation. Here are a few examples.

- Wind turbines do not produce constantly. Their performance varies based on the actual power of the wind. This can be from zero to storm force!

- Efficiency is not the best available: a modern turbine running at its desired speed can deliver electricity to 500 households. Count quickly how many would be needed for a city with a population of 20 million?

- It is not true that wind turbines are 100% environment friendly, because when factories build them, they do emit some pollution into the air. But that is a onetime pollution against the constant negative effects of regular electricity production with for example burning of coal.

- They are noisy mechanisms. One turbine can produce the same level of noise as a car travelling at 60mph on the highway! You certainly don’t want that under your window constantly. But almost all of these are against the larger, industrial versions, not the ones built for home usage.

Now let’s hear a few pros!

- The wind is free, and it can be captured with good efficiency nowadays compared to the results some decades ago.

- They do not take large portion of lands like solar farms do! The land around these small towers can be cultivated or used in a different way without any problems!

- A large group of people thinks they add to the view of the landscape!

- If you live on the top of the hill or miles away from any civilization you can still generate your own power with smaller wind turbines!

- And the last and best one: you can build a wind turbine yourself! It’s an easy process and there are complete guides available.

Donna asks…

Can someone pls tell me some good jokes and amazing facts about wind energy ? I really need them quickly!?

I have a presentation due and i need some good jokes and amazing facts about wind energy . PLs help!

Windmill Farms answers:

Hey Dreamer, a couple interesting links below. I have better luck with stuff like this doing a dogpile search rather than google, not sure why. Try “” and ask for funny wind turbine jokes, or windmill jokes, or stories. Here are a couple quotes I like to use when I teach our wind and solar class at the local schools here:

“The path we take today could ease anothers journey tomorrow” Rajendra Pachauri

“The problems facing humanity today cannot be solved with the same level of conciousness that created them.” Albert Einstein

For some good facts, check out the websites or sources below. Take care, Rudydoo

“What did the 1kilowatt turbine say when he met the 5 megawatt turbine? “Man, that guy blew me away!!”

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Renewable Energy Definition

Robert asks…

what are these science definitions?

my physical science homework was to get the definitions for these words, but i forget to bring my book home and all of the definitions online are way too complex for this 8th grade science course. could you guys give me a simple definition for them? thanks!

2)kinetic energy
3)potential energy
4)mechanical energy
5)energy conservation
7)law of conservation
8)energy resource
9)nonrenewable resources
10)fossil fuels
11)renewable resources

i know i could get them by myself just by thinking about it, but i just want to make sure. thanks again guys!!!

Windmill Farms answers:

1. Ability to cause change .
2. Energy in the form of motion
3. Stored energy, or the potential to move downwards .
4. The total amt of kinetic & potential energy .
5. Energy may change form but it cannot be created or destoryed under ordinary conditions.
6. The force that opposed motion between two sufaces that are touching each other .
7. What law of conservation ?, momentum ?,
well if it’s that then : the total amt of momentum of a group of objects does not change unless outside forces acts upon the objects.
8. A source of useable power, which can be drawn on when needed.
9. Energy resource that is either replenished very slowly or is not replenished at all by natural processes.
10. Natural resources, such as coal, oil and natural gas, containing hydrocarbons.
11. Source of electricity generated from solar, wind, biomass, small hydroelectric facilities,

Maria asks…

What is consevation of energy?

Definition of conservation of energy.

Windmill Farms answers:

There are 2 definitions of “conservation of energy” :
1) The physics definition is that the total amount of energy in an isolated system remains constant over time. This definition starts to become quite complicated.
2) In the essence of everyday living, the conservation of energy is the act of using only the energy that you need. Taking actions in your life to reduce your energy consumption as much as possible, including unplugging appliances and shutting the lights of when not needed.
I hope this answers your question!
I have a blog on renewable energy and green living, you are welcome to check it out.

Donald asks…


Windmill Farms answers:

Renewable energy
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Environmental science
Environmental technology
Anaerobic digestion
Sewage treatment
Water purification
Waste management
Waste minimisation
Energy conservation
Renewable energy

Renewable energy (sources) or RES capture their energy from existing flows of energy, from on-going natural processes, such as sunshine, wind, flowing water (hydropower), biological processes, and geothermal heat flow. The most common definition is that renewable energy is from an energy resource that is replaced by a natural process at a rate that is equal to or faster than the rate at which that resource is being consumed. For example, solar photovoltaic technology harvests energy from the sun, but only a fraction of the total amount of solar energy is harvested. It is a subset of sustainable energy.

Most renewable forms of energy, other than geothermal and tidal power, ultimately come from the sun. Some forms are stored solar energy such as rainfall and wind power which are considered short-term solar-energy storage, whereas the energy in biomass is accumulated over a period of months, as in straw, or through many years as in wood. Capturing renewable energy by plants, animals and humans does not permanently deplete the resource. Fossil fuels, while theoretically renewable on a very long time-scale, are exploited at rates that may deplete these resources in the near future (see: Hubbert peak).

Renewable energy resources may be used directly, or used to create other more convenient forms of energy. Examples of direct use are solar ovens, geothermal heating, and water- and windmills. Examples of indirect use which require energy harvesting are electricity generation through wind turbines or photovoltaic cells (PV cells), or production of fuels such as biogas from anaerobic digestion or ethanol from biomass (see alcohol as a fuel). A parameter sometimes used in renewable energy is the tonne of oil equivalent (toe). This is equal to 10,000 Mcal or 41,868 MJ of energy.[1]

In a sense, renewable energy may be categorized as free energy, although most renewable energy sources would not normally be called “free energy”. In engineering, free energy means an energy source available directly from the greater environment and which cannot be expected to be depletable by humans. Renewable energy development is concerned with the use of renewable energy sources by humans. For aspects of renewable energy use in modern societies see Renewable energy development. Modern interest in renewable energy development is linked to concerns about exhaustion of fossil fuels and environmental, social and political risks of extensive use of fossil fuels and nuclear energy. For a general discussion, see future energy development.

Contents [hide]
1 Modern sources of renewable energy
1.1 Wind energy
1.2 Water power
1.3 Solar energy
1.3.1 Geothermal energy
1.4 Biofuel
1.4.1 Liquid biofuel
1.4.2 Solid biomass
1.4.3 Biogas
2 Small scale energy sources
3 Criticisms
3.1 Aesthetics, habitat hazards and land use
3.2 Concentration
3.3 Proximity to demand
3.4 Availability
4 Issues
4.1 Fossil fuels
4.2 Transmission
4.3 Load balancing
4.4 Market development of renewable heat energy
4.5 Aviation
5 Historical usage of renewable energy
6 See also
7 External links
8 References

Modern sources of renewable energy
Wind energy
Main article: Wind power
As the sun heats up the Earth unevenly, winds are formed. The kinetic energy in the wind can be used to run wind turbines, some capable of producing 5 MW of power. The power output is a function of the cube of the wind speed, so such turbines generally require a wind in the range 5.5 m/ (20 km/h), and in practice relatively few land areas have significant prevailing winds. Luckily, offshore or at high altitudes, the winds are much more constant.

There are now many thousands of wind turbines operating in various parts of the world, with utility companies having a total capacity of 59,322 MW[2][3]. Capacity in this case means maximum possible output which does not count load factor.

New wind farms and offshore wind parks are being planned and built all over the world. This has been the most rapidly-growing means of electricity generation at the turn of the 21st century and provides a complement to large-scale base-load power stations. Most deployed turbines produce electricity about 25% of the time (load factor 25%), but some reach 35%. The load factor is generally higher in winter. It means that a 5 MW turbine can have average output of 1.7 MW in the best case.

Global winds long-term technical potential is believed to be 5 times current global energy consumption or 40 times current electricity demand. This requires 12.7% of all land area, or that land area with Class 3 or greater potential at a height of 80 meters. It assumes that the land is covered with 6 large wind turbines per square kilometer. Offshore resources experience mean wind speeds of ~90% greater than that of land, so offshore resources could contribute substantially more energy.[4] This number could also increase with higher altitude ground based or airborne wind turbines.[5]

Wind strengths vary and thus cannot guarantee continuous power. Some estimates suggest that 1,000 MW of wind generation capacity can be relied on for just 333 MW of continuous power. While this might change as technology evolves, advocates have suggested incorporating wind power with other power sources, or the use of energy storage techniques, with this in mind. It is best used in the context of a system that has significant reserve capacity such as hydro, or reserve load, such as a desalination plant, to mitigate the economic effects of resource variability.

Wind power is renewable and is one of the few energy sources that contributes to greenhouse gas mitigation, because it removes energy directly from the atmosphere without producing net emissions of greenhouse gases such as carbon dioxide and methane (others greenhouse gas mitigating energy sources include solar thermal and ocean thermal).

Water power
Main article: Water power
Energy in water can be harnessed and used, in the form of motive energy or temperature differences. Since water is about a thousand times heavier than air, even a slow flowing stream of water can yield great amounts of energy.

There are many forms:

Hydroelectric energy, a term usually reserved for hydroelectric dams.
Tidal power, which captures energy from the tides in vertical direction. Tides come in, raise water levels in a basin, and tides roll out. The water must pass through a turbine to get out of the basin. If the basin is a river delta then silt will block the turbine.
Tidal stream power, Captures a stream of water as it is pushed horizontally around the world by tides.
Wave power, which uses the energy in waves. The waves will usually make large pontoons go up and down in the water, leaving an area with no waves in the “shadow”.
Ocean thermal energy conversion (OTEC), which uses the temperature difference between the warmer surface of the ocean and the cool (or cold) lower recesses. To this end, it employs a cyclic heat engine.
Deep lake water cooling, although not technically an energy generation method, can save a lot of energy in summer. It uses submerged pipes as a heat sink for climate control systems. Lake-bottom water is a year-round local constant of about 4 °C.
Blue energy, the reverse of desalination. A difference in salt concentration exists between seawater and river water. This gradient can be utilized to generate electricity by separating positive and negative ions by ion specific membranes. Brackish water is produced. This form of energy is in research, costs are not the issue, tests on pollution of the membrane are in progress. At this moment it is predicted that if everything works out, 1/3 of the electricity needs in the Netherlands can be covered with this system.(2005)
Hydroelectric power is probably not a major option for the future of energy production in the developed nations because most major sites within these nations with the potential for harnessing gravity in this way are either already being exploited or are unavailable for other reasons such as environmental considerations. However, micro hydro may be an option for small scale applications such as single farms, homes or small businesses.

Building a dam often involves flooding large areas of land, this can change habitats so immensely that this risk of endangering local and non local wildlife is great. For example, since damming and redirecting the waters of the Platte River in Nebraska for agricultural and energy use, many native and migratory birds such as the Piping Plover and Sandhill Crane have become increasingly endangered.

Wave and tidal stream power schemes exist but require development capital.

OTEC has not been field tested on a large scale.

Critics of hydroelectric dams state that they may produce significant amounts of carbon dioxide and methane from rotting vegetation. In some cases produce more of these greenhouse gases than power plants running on fossil fuels[1]. Dam failures, while rare, are potentially serious – the Banqiao Dam failure in China killed 171,000 people, many more than the immediate death toll in the Chernobyl disaster.

Solar energy

The solar panels (photovoltaic arrays) on this small yacht at sea can charge the 12 V batteries at up to 9 amperes in full, direct sunlight.Main article: Solar power
Since most renewable energy is ultimately “solar energy” this term is slightly confusing and used in two different ways: firstly as a synonym for “renewable energies” as a whole and secondly for the energy that is directly collected from sunlight. In this section it is used in the latter category. Solar power can be used to:

generate electricity using solar cells
generate electricity using concentrated solar power
generate electricity by heating trapped air which rotates turbines in a Solar updraft tower.
Heat buildings, directly. Careful positioning of windows and use of brises soleil can maximise inflow of light at the times it is most needed, heating the building while preventing overheating during midday and summer.
Heat buildings, through heat pumps
heat foodstuffs, through solar ovens.
Heat water for domestic consumption and heating using rooftop solar panels.
Heat and cool air through use of solar chimneys.
Obviously the sun does not provide constant energy to any spot on the Earth, so its use is limited without a means for energy storage. Solar cells are often used to power batteries, as most other applications would require a secondary energy source, to cope with outages. Some homeowners use a solar system which sells energy to the grid during the day, and draw energy from the grid at night; this is to everyone’s advantage, since power demand for air conditioning is highest during the day.

Problems generally associated with electricity from solar cells:

It is not available in dark or cloudy conditions, hence producing variable voltages.
Solar panels are expensive and energy collection is not yet optimized.
The current generated is only of DC type. It must be converted to AC current before transmission.
Concentrated solar power plants work best in hot deserts and other places with plenty of direct sunshine. There are methods for storing solar heat so that electricity generation may continue through the night and even on cloudy days.

Geothermal energy
Main article: Geothermal energy
Geothermal energy ultimately comes from radioactive decay in the core of the Earth, which heats the Earth from the inside out, and from the sun, which heats the surface. It can be used in three ways:

Geothermal electricity
Geothermal heating, through deep Earth pipes
Geothermal heating, through a heat pump.
Usually, the term ‘geothermal’ is reserved for thermal energy from within the Earth.

Geothermal electricity is created by pumping a fluid (oil or water) into the Earth, allowing it to evaporate and using the hot gases vented from the earth’s crust to run turbines linked to electrical generators.

The geothermal energy from the core of the Earth is closer to the surface in some areas than in others. Where hot underground steam or water can be tapped and brought to the surface it may be used to generate electricity. Such geothermal power sources exist in certain geologically unstable parts of the world such as Iceland, New Zealand, United States, the Philippines and Italy. The two most prominent areas for this in the United States are in the Yellowstone basin and in northern California. Iceland produced 170 MW geothermal power and heated 86% of all houses in the year 2000 through geothermal energy. Some 8000 MW of capacity is operational in total.

Geothermal heat from the surface of the Earth can be used on most of the globe directly to heat and cool buildings. The temperature of the crust a few feet below the surface is buffered to a constant 7 to 14 °C (45 to 58 °F), so a liquid can be pre-heated or pre-cooled in underground pipelines, providing free cooling in the summer and, via a heat pump, heating in the winter. Other direct uses are in agriculture (greenhouses), aquaculture and industry.

Although geothermal sites are capable of providing heat for many decades, eventually specific locations cool down. Some interpret this as meaning a specific geothermal location can undergo depletion, and question whether Geothermal is renewable.

Small scale geothermal heating can also be used to directly heat buildings: there are many names for this technology including “Ground Source Heat Pump” technology, and “Geoexchange”. People can get water energy by turning on their taps, its as simple as that!

Main article: Biofuel
Plants use photosynthesis to store solar energy in the form of chemical energy. Biofuel is any fuel that derives from biomass, including living organisms or their metabolic byproducts, such as cow manure.

Typically biofuel is burned to release its stored chemical energy. Research into more efficient methods of converting biofuels and other fuels into electricity utilizing fuel cells is an area of very active work. Biomass, also known as biomatter, can be used directly as fuel or to produce liquid biofuel. Agriculturally produced biomass fuels, such as biodiesel, ethanol and bagasse (often a by-product of sugar cane cultivation) can be burned in internal combustion engines or boilers.

A drawback is that all biomass needs to go through some of these steps: it needs to be grown, collected, dried, fermented and burned. All of these steps require resources and an infrastructure. However, the United States government passed legislation that requires the integration of 7.5 billion U.S. Gallons (28,000,000 m³) of ethanol into the gasoline supply experts estimate that six billion dollars of investment will be created along with 200,000 additional jobs in the United States.

Biomatter energy, under the right conditions, is considered to be renewable.

Liquid biofuel
Liquid biofuel is usually bioalcohol such as ethanol and biodiesel and virgin vegetable oils. Biodiesel can be used in modern diesel vehicles with little or no modification to the engine and can be obtained from waste and virgin vegetable and animal oil and fats (lipids). Virgin vegetable oils can be used in modified diesel engines. In fact the Diesel engine was originally designed to run on vegetable oil rather than fossil fuel. A major benefit of biodiesel is lower emissions. The use of biodiesel reduces emission of carbon monoxide and other hydrocarbons by 20 to 40 percent. In some areas corn, sugarbeets, cane and grasses are grown specifically to produce ethanol (also known as alcohol) a liquid which can be used in internal combustion engines and fuel cells. Ethanol is being phased into the current energy infrastructure. E85 is a fuel composed of 85% ethanol and 15% gasoline that is currently being sold to consumers.

The EU plans to add 5% bioethanol to Europe’s petrol by 2010. For the UK alone the production would require 12,000 square kilometres of the country’s 65,000 square kilometres of arable land assuming that no biofuels are created using waste produces from other agriculture. The supermarket chain Tesco has started adding the 5% bioethanol to the petrol it sells as of January 2006.

In the future, there might be bio-synthetic liquid fuel available. It can be produced by Fishcer-Tropsch processes, also called Biomass-To-Liquids (BTL). Please also see : Fossil fuel beneath. Source: and also

Solid biomass
Direct use is usually in the form of combustible solids, either wood, the biogenic portion of municipal solid waste or combustible field crops. Field crops may be grown specifically for combustion or may be used for other purposes, and the processed plant waste then used for combustion. Most sorts of biomatter, including dried manure, can actually be burnt to heat water and to drive turbines.

Sugar cane residue, wheat chaff, corn cobs and other plant matter can be, and is, burnt quite successfully. The process releases no net CO2.

Solid biomass can also be gasified, and used as described in the next section.

Main article: Biogas
Many organic materials can release gases, due to metabolisation of organic matter by bacteria (anaerobic digestion, or fermentation). Landfills actually need to vent this gas (called landfill gas) to prevent dangerous explosions. Animal faeces releases methane under the influence of anaerobic bacteria.

Also, under high pressure, high temperature, anaerobic conditions many organic materials such as wood can be gasified to produce gas. This is often found to be more efficient than direct burning. The gas can then be used to generate electricity and/or heat.

Biogas can easily be produced from current waste streams, such as: paper production, sugar production, sewage, animal waste and so forth. These various waste streams have to be slurried together and allowed to naturally ferment, producing methane gas. This can be done by converting current sewage plants into biogas plants. When a biogas plant has extracted all the methane it can, the remains are sometimes better suitable as fertilizer than the original biomass.

Alternatively biogas can be produced via advanced waste processing systems such as mechanical biological treatment. These systems recover the recyclable elements of household waste and process the biodegradable fraction in anaerobic digesters.

Renewable natural gas is a biogas which has been upgraded to a quality similar to natural gas. By upgrading the quality to that of natural gas, it becomes possible to distribute the gas to the mass market via the existing gas grid.’

Small scale energy sources
There are many small scale energy sources that generally cannot be scaled up to industrial size. A short list:

Piezoelectric crystals generate a small voltage whenever they are mechanically deformed. Vibration from engines can stimulate piezoelectric crystals, as can the heels of shoes
Some wristwatches are already powered by kinetics, in this case movement of the arm
Thermoelectric generators produce energy from the heat difference between two objects. This is also used to power a type of wristwatch, as heat energy from the human body is radiated through the watch into the environment.
Special antennae can collect energy from stray radio waves or theoretically even light (EM radiation).
Some critics charge that renewable energy is an arbitrary definition with no bearing on how much an energy source pollutes, how dangerous it is, whether it takes up a large amount of land that could be left wild or farmed for food, whether the source of the renewable energy will last a very long time, or even whether a given energy source produces a net amount of energy. Supporters respond that most renewable energies are ultimately powered by the Sun, the Earth, or the Moon, so the underlying sources for these energies are expected to last for billions of years. Of course, this does not mean that renewable energy infrastructure, like hydroelectric dams, will last forever. Events like the shifting of riverbeds, or changing weather patterns could potentially alter or even halt the function of hydroelectric dams. But, while this may be a concern in theory, few if any examples of such problems have occured in modern times. Most renewable energy infrastructure seems to be at least as permanent and relieable as that of fossil fuel energy sources. While most renewable energy sources do not produce direct pollution, some of the inputs required to produce renewable energy, such as the crops grown to create ethanol or biodiesel, require energy inputs. The exact amount of energy required to grow crops varies widely, since a number of modern farming methods can significantly reduce the amount of energy that must be used. It is also very tricky to account for all energy inputs to biofuels. Opponents of corn ethanol production in the U.S. Often quote the work of David Pimentel and Tadeusz Patzek. Pimentel is a retired Entomologist, and Patzek is a Geological Engineer from Berkeley. Both have been exceptionally critical of ethanol and other biofuels. Their studies contend that ethanol, and biofuels in general, are “energy negative,” meaning they take more energy to produce than is contained in the final product. However, this does not appear to be the consensus opinion among scientists. A report by the U.S. Department Agriculture compared the methodologies used by a number of researchers on this subject and found that the majority of researchers think the energy balance for ethanol is positive. In fact, a large number of recent studies, including an article in the Journal Science offer the consensus opinion that fuels like ethanol are energy positive. Furthermore, it should be pointed out that fossil fuels also require significant energy inputs which have seldom been accounted for in the past. According to information from the American Council for Ethanol, “ethanol has a 125 percent positive energy balance, compared to 85 percent for gasoline.” Ultimately, the issue of energy balance may be the wrong thing to worry about, anyway. In the case of gasoline, it is a convenient, portable fuel, even though it is energy negative. Batteries are also energy negative, since you put more energy into them than you can get out. Nonetheless, they function as a useful energy storage mechanism. Electricity generation often takes 2.5 times more energy to generate than the final product contains, but the key point to understand in all these cases is that forms of energy like electricity are considered higher quality energy than the original energy sources that were used to make them. This is because they can do things like power a light or a computer that the original energy sources they were made from, like coal, cannot do. It is the high quality of this energy that would justify producing it even if it did take more energy than you directly recovered from the final product.

Aesthetics, habitat hazards and land use
Some people dislike the aesthetics of wind turbines or bring up nature conservation issues when it comes to large solar-electric installations outside of cities. Some people try to utilize these renewable technologies in an efficient and aesthetically pleasing way: fixed solar collectors can double as noise barriers along highways, roof-tops are available already and could even be replaced totally by solar collectors, amorphous photovoltaic cells can be used to tint windows and produce energy etc.

Some renewable energy capture systems entail unique environmental problems. For instance, wind turbines can be hazardous to flying birds, while hydroelectric dams can create barriers for migrating fish – a serious problem in the Pacific Northwest that has decimated many salmon populations.

Another problem with many renewables, especially biomass and biofuels, is the large amount of land required, which otherwise could be left as wilderness.

Another inherent difficulty with renewables is their variable and diffuse nature (the exception being geothermal energy, which is however only accessible in exceptional locations). Since renewable energy sources are providing relatively low-intensity energy, the new kinds of “power plants” needed to convert the sources into usable energy need to be distributed over large areas.

Electrical power consumption in Western countries averages about 100 watts continuously per person (i.e. About 1 MWh per year). In cloudy Europe this would require about eight square meters of solar panels per person, assuming a below-average solar conversion rate of 12.5%. Systematic electrical generation requires reliable overlapping sources or some means of storage on a reasonable scale (pumped-storage hydro systems, batteries, hydrogen fuel cells, etc). So, because of current costs of such energy storage systems, a stand-alone system is only economic in rare cases, or where a connection to a public grid would be impractical.

Proximity to demand
The geographic diversity of resources is also significant. Some countries and regions have significantly better resources than others in particular RE sectors. Some nations have significant resources at distance from the major population centers where electricity demand exists. Exploiting such resources on a large scale is likely to require considerable investment in transmission and distribution networks as well as in the technology itself.

Rooftop photovoltaic arrays are especially attractive in that most of the power they produce is consumed in the structure on which they are mounted or in other nearby buildings.

One recurring criticism of renewable sources is their intermittent nature. Sunlight is only available during the day when the sun is well above the horizon when the sky is not cloudy. Wind energy is typically available much less than half the time. Wave energy is continuously available, although wave intensity varies by season. A wave energy scheme installed in Australia is generating electricity with an 80% availability factor.

Fossil fuels
Main article: Fossil fuel
Renewable energy sources are fundamentally different from fossil fuel or nuclear power plants because the Sun will ‘power’ these ‘power plants’ (meaning sunlight, the wind, flowing water, etc.) for the next 4 billion years. They also do not directly produce greenhouse gases and other emissions, as fossil fuel combustion does. Most do not introduce any global new risks such as nuclear waste.

Fossil fuels are not considered a renewable energy source, but are often compared and contrasted with renewables in the context of future energy development.

The traditionally, though not universally, held Western (biogenic) theory postulates that fossil fuels are the altered remnants of ancient plant and animal life deposited in sedimentary rocks. They were formed millions of years ago and have rested underground, mostly dormant, since that time.

In contrast, the Abiogenic petroleum origin theory states that petroleum (or crude oil) is primarily created from non-biological sources of hydrocarbons located deep in the Earth. This view was championed by Fred Hoyle in his book The Unity of the Universe.

Though it is possible to produce complex hydrocarbons artificially by using the Fischer-Tropsch process, this process does not generate energy, and cannot be considered a large scale solution to the energy problem. However, liquid fuels and hydrocarbons are needed, and the Fischer-Tropsch-process can use biomass, hydrogen and oxygen produced with renewable energy, as feedstocks.

The coal industry in the US is publicly claiming coal is renewable energy because the coal was originally biomass. However, the biomass of fossil fuels was produced on the time scale of millions of years through a series of events and it is considered to be a deposit of energy, not an energy flow. Some scientists hold the view that the formation of fossil fuels was a one-time event, made possible by unique conditions during the Devonian period, such as increased oxygen levels and huge swamps.

When the term renewable was introduced, it was a generally held belief that the Earth’s sources would be depleted within some 50 years. Since then, large deposits of deep-Earth oil have been found, which has extended this timetable. Because the current rate of consumption exceeds the rate of renewal (if, indeed, there is renewal of fossil fuels), the Earth will eventually run out of fossil fuels (see peak oil).

If renewable and distributed generation were to become widespread, electric power transmission and electricity distribution systems might no longer be the main distributors of electrical energy but would operate to balance the electricity needs of local communities. Those with surplus energy would sell to areas needing “top ups”. That is, network operation would require a shift from ‘passive management’ – where generators are hooked up and the system is operated to get electricity ‘downstream’ to the consumer – to ‘active management’, wherein generators are spread across a network and inputs and outputs need to be constantly monitored to ensure proper balancing occurs within the system. Some Governments and regulators are moving to address this, though much remains to be done. One potential solution is the increased use of active management of electricity transmission and distribution networks. This will require significant changes in the way that such networks are operated.

However, on a small scale, use of renewable energy that can often be produced “on the spot” lowers the requirements electricity distribution systems have to fulfill. Current systems, while rarely economically efficient, have proven an average household with a solar panel array and energy storage system of the right size needs electricity from outside sources for only a few hours every week. Hence, advocates of renewable energy believe electricity distribution systems will become smaller and easier to manage, rather than the opposite.

Load balancing
A common critisim of renewable power is that generators such as wind turbines or solar arrays are liable to suffer variable output. To handle this characteristic, a more balanced power supply may be obtained if the various renewable sources are interconnected and distributed. Indeed, distribution and redundancy are already features of existing electrical grids. The challenge of variable power supply may be further alleviated by energy storage. For this purpose hydroelectric dams provide an excellent energy storage mechanism. As a case example, Denmark exports wind power to its neighbours during peak periods. Meanwhile, during times of deficiency the power may be imported, particularly from hydroelectric sources. Combined with ‘sheddable’ electricity loads, real-time pricing and energy stocking, renewable power has the potential to realiably satisfy demand.

Market development of renewable heat energy
Renewable heat is an application of renewable energy, namely the generation of heat from renewable sources. In some cases, contemporary discussion on renewable energy focuses on the generation of electrical, rather than heat, energy. This is despite the fact that many colder countries consume more energy for heating than as electricity. On an annual basis the United Kingdom consumes 350 TWh[6] of electric power, and 840 TWh of gas and other fuels for heating. The residential sector alone consumes a massive 550 TWh of energy for heating, mainly in the form of gas.[7]

Renewable electric power is becoming cheap and convenient enough to place it, in many cases, within reach of the average consumer. By contrast, the market for renewable heat is mostly inaccessible to domestic consumers due to inconvenience of supply, and high capital costs. Heating accounts for a large proportion of energy consumption, however a universally accessible market for renewable heat is yet to emerge. Also see renewable energy development.

Kerosene, a non-renewable fuel, is currently considered to be the only fuel practical and economic for commercial aviation. Although hydrogen has a high energy density, the need for heavy fuel tanks and fuel-cell stacks rules it out for aircraft. Biodiesel, another candidate aviation fuel, is problematic due its tendency to freeze more readily than kerosene.

Historical usage of renewable energy
Throughout history, various forms of renewable and non-renewable energies have been employed.

Wood was the earliest manipulated energy source in human history, being used as a thermal energy source through burning, and it is still important in this context today. Burning wood was important for both cooking and providing heat, enabling human presence in cold climates. Special types of wood cooking, food dehydration and smoke curing, also enabled human societies to safely store perishable foodstuffs through the year. Eventually, it was discovered that partial combustion in the relative absence of oxygen could produce charcoal, which provided a hotter and more compact and portable energy source. However, this was not a more efficient energy source, because it required a large input in wood to create the charcoal.
Animal power for vehicles and mechanical devices was originally produced through animal traction. Animals such as horses and oxen not only provided transportation but also powered mills. Animals are still extensively in use in many parts of the world for these purposes.
Human power for vehicles, mechanical devices and individual non-machine-aided transportation has been employed throughout human history. Slaves have been used for powering boats and powering construction machinery such as that used to build the Egyptian pyramids. Today, slaves have largely been replaced by other sources of power to the degree that the average American accesses the same amount of power that otherwise would require 50 slaves. One of the largest uses of human power today is bicycling, which remains the most energy-efficient means of transportation.
Water power eventually supplanted animal power for mills, wherever the power of falling water in rivers was exploitable . Water power through hydroelectricity continues to be the least expensive method of storing and generating dispatchable energy throughout the world. Historically as well as presently, hydroelectricity provides more renewable energy than any other renewable source.
Animal oil, especially whale oil was long burned as an oil for light.
Wind power has been used for several hundred years. It was originally used via large sail-blade windmills with slow-moving blades, such as those seen in the Netherlands and mentioned in Don Quixote. These large mills usually either pumped water or powered small mills. Newer windmills featured smaller, faster-turning, more compact units with more blades, such as those seen throughout the Great Plains. These were mostly used for pumping water from wells. Recent years have seen the rapid development of wind generation farms by mainstream power companies, using a new generation of large, high wind turbines with two or three immense and relatively slow-moving blades. Today, wind power is the fastest growing energy source in the world.
Solar power as a direct energy source has not been captured by mechanical systems until recent human history, but was captured as an energy source through architecture in certain societies for many centuries. Not until the twentieth century was direct solar input extensively explored via more carefully planned architecture (passive solar) or via heat capture in mechanical systems (active solar) or electrical conversion (photovoltaic). Increasingly today the sun is harnessed for heat and electricity.
Attempts to harness the power of ocean waves appears in drawings and patents back to the 19th century. Modern attempts to capture wave power began in the 1970′s by Professor Steven Salter who started the Wave Energy Group at the University of Edinburgh in Scotland. There are several pilot plants generating power into the grid, and many new and curious designs are in various stages of development and testing.
See also
Hydrogen economy
Solar chimney
Nuclear power phase-out
Renewable energy development
Mitigation of global warming
Mechanical Biological Treatment
Soft energy path
Sustainable energy
anaerobic digestion
Wave Power
Wind power
Tidal power
Trans-Mediterranean Renewable Energy Cooperation (TREC)
Renewable energy in the European Union
External links
This article or section may contain external links added only to promote a website, product, or service – otherwise known as spam.
If you are familiar with the content of the external links, please help by removing commercial links, in accordance with Wikipedia:External links. (you can help!)Wikimedia Commons has media related to:
Category:Renewable energyWikinews has news related to:
Oil prices drive new investment in clean technologyAlternative Energy Development Board, Pakistan
Renewable Energy Industry, press releases, companies, products, stocks
Oregon Institute of Technology
Green Energy Building List and Google Map
Atlas of Renewable Energy (in English, French & German)
World Council for Renewable Energy WCRE
Surface meteorology and Solar Energy – a renewable energy resource for data and images
Renewable Energy News from around the world
SolarDrome Renewable Energy from Around the Web
International Energy Foundation
National Renewable Energy Laboratory (American)
Renewable Energy Policy Network REN21
Genome News Network (GNN) Energy News Collection of articles about how advances in genomics is leading to advances in energy production.
EU Intelligent Energy, energy efficiency and renewables.
Green Wiki Collective articles on renewable energy and other topics related to sustainable living
Energyorbit :: Towards Sustainable Power and Renewable Energy
The Source for Renewable Energy A directory to more than 9000 renewable energy businesses worldwide
The wide world of renewable energy
Green Energy News Brilliant source of Alternative Engery news.
DocRenewableEnergy Document references on Renewable Energy – multilingual site
Renewable Energy – Beginner’s tutorial on using renewable fuel in a diesel engine
The British Library – finding information on the renewable energy industry
^ Unit Converter IEA Statistics (URL accessed January 30, 2006)
^ “Wind energy is a relatively young but rapidly expanding industry. Over the past decade, global installed capacity has increased from 2,500 megawatts (MW) in 1992 to just over 40,000 MW at the end of 2003, at an annual growth rate of near 30%.” EWEA Executive summary (pdf) (URL accessed January 30, 2006)
^ “Record year for wind energy : global wind power market increased by 43% in 2005″ Press Release with 2005 statistics (PDF) (URL accessed February 20, 2006)
^ “Offshore stations experience mean wind speeds at 80 m that are ~90% greater than over land on average. Evaluation of global wind power
“Overall, the researchers calculated winds at 80 meters [300 feet] traveled over the ocean at approximately 8.6 meters per second and at nearly 4.5 meters per second over land [20 and 10 miles per hour, respectively].” Global Wind Map Shows Best Wind Farm Locations (URL accessed January 30, 2006)
^ “High-altitude winds could provide a potentially enormous renewable energy source, and scientists like Roberts believe flying windmills could put an end to dependence on fossil fuels. At 15,000 feet, winds are strong and constant. On the ground, wind is often unreliable — the biggest problem for ground-based wind turbines.” Windmills in the Sky (URL accessed January 30, 2006)
^ Department of Trade and Industry report UK Energy in Brief July 2005 (URL accessed Mar 18, 2006)
^ Department of Trade and Industry, 2005 study on Renewable Heat (URL accessed Mar 18, 2006)
U.S. Energy Information Administration provides a wide range of statistics and information on the industry.
Boyle, G. (ed.), Renewable Energy: Power for a Sustainable Future. Open University, UK, 1996.
U.S. DOE Energy Efficiency and Renewable Energy (EERE) Home Page

Sandra asks…

What is solar energy?

Ummm i’m not dumb i know what it is but i just wanted a more detailed explenation :)

Windmill Farms answers:

I googled what is solar energy to try and give you a detailed answer and here are some of the definitions that i came up with… Hope theyre what you were looking for…

•energy from the sun that is converted into thermal or electrical energy; “the amount of energy falling on the earth is given by the solar constant, but very little use has been made of solar energy”

•Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies

•Solar energy uses semiconductor material to convert sunlight into electric currents. Although solar energy only provides 0.15% of the world’s power and less than 1% of US energy, experts believe that sunlight has the potential to supply 5,000 times as much energy as the world currently consumes. …

•Energy derived from sunlight — in a home or office

•Energy derived ultimately from the sun. It can be divided into direct and indirect categories. Most energy sources on Earth are forms of indirect solar energy, although we usually don’t think of them in that way. …

•Energy given out by the sun. Includes all the various rays given off by the sun.

•Energy from the sun, also known as solar radiation and short-wave radiation. Solar energy includes ultra-violet radiation, visible radiation, and infra-red radiation

•Energy from the sun that can be used for heating or to make electricity.

•is the ultimate energy source driving the earth. Though only one billionth of the energy that leaves the sun actually reaches the earth’s surface, this is more than enough to meet the world’s energy requirements. …

•Power collected from sunlight used to generate electricity.

•The radiant energy from the Sun that influences Earth’s climate and weather and sustains life. It includes visible light and several non-visible frequencies such as ultraviolet light. …

•Energy gained from the sun, and can be collected by solar panels. This is a renewable resource. Plants and producers also collect solar energy

•The driving force behind almost all climatic changes on Earth is the Sun. Sunlight that reaches Earth’s atmosphere experiences different fates

use this site, its got a lot of detailed information on it…


Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on earth. Only a minuscule fraction of the available solar energy is used.

Solar powered electrical generation relies on heat engines and photovoltaics. Solar energy’s uses are limited only by human ingenuity. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, daylighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes.To harvest the solar energy, the most common way is to use solar panels.

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.

Donna asks…

What is the difference between renewable and sustainable energy sources?

Can something be sustainable but not renewable?

Windmill Farms answers:

Renewable energy is energy generated from natural resources—such as sunlight, wind, rain, tides, and geothermal heat—which are renewable (naturally replenished)Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources.

Each of these sources has unique characteristics which influence how and where they are used.

Sustainable energy sources are most often regarded as including all renewable sources, such as biofuels, solar power, wind power, wave power, geothermal power and tidal power. It usually also includes technologies that improve energy efficiency

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Wind Power Cost

Ruth asks…

how do wind and hydroelectric power plants compare to natural gas in costs?

My county is building a natural gas power plant which will cost $427.4 million. How does wind and hydroelectric power compare to that? How much cheaper overall?

Windmill Farms answers:

Cheapest among the three is the NG power plant. Then comes wind and lastly the Hydro electric power plant.
Operating cost wise it will be the reverse. As per feasibility NG based power plant can be constructed anywhere where gas pipe line is running. But wind power requires favorable wind movement and also excess capacity is to be build to take care of the wind speed variation. Hydro on the other hand can be built only in areas where water can be stored, where abundant rainfall is there etc.

Lisa asks…

Dream of building your own off the grid cabin? or have you done it? What are/were your biggest obstacles?

For years I have been planning to build my own cabin. I very much want to live a much simpler lifestyle. Info on do-it-yourself, affordable solar power has been my biggest obstacle. Wind power would also be ideal in my area, but there’s even less info on that.

Windmill Farms answers:

Solar works well for heating water; assuming you have a source; but prices for Collector cells and storage of the energy aren’t strictly at a point yet for an “OFF THE GRID” lifestyle. No offense but I find trendy terms so “trendy”

Wind power or Solar; would be still be cost prohibitive; depending on how much POWER you actually need/want. Certainly that also depends on how primitive you can endure; and/or how far OFF the GRID you think you can be.

The cabin itself will be the easy task.

Steven Wolf

Sharon asks…

Why Isn’t Pelosi Forcing the Elderly & Poor to Buy Wind Power to Air Condition Their Houses?

Wind power is available for an EXTRA $.05/kwh in Obama supporting PA.

But few residents buy it.

Isn’t it time for Democrats to tell all of us — poor, elderly, rich, young — that we must use wind energy to help save the planet no matter what it costs?

Windmill Farms answers:

Wind power is a good idea but many people are understandably reluctant to pay even more money to their power companies. There must be a better way.

James asks…

where can I find grants to help build a wind turbine?

I live in MT. I am looking for grants that would help pay for some or all of the cost to build and hook a wind turbine to power my house. The costs for wind turbine are expensive but I would like to try to find alternative energy sources for my home.

Windmill Farms answers:

Forget about grants. If you want it bad enough you will get off your lazy butt and earn the money to build one. Why should someone else pay for you to have a wind turbine?

Helen asks…

How will wind power create the materials needed to manufacture wind turbines?

Wind turbines have the evil plastic in their structure. Also wind provides energy, not matter.

Windmill Farms answers:

Wind power provides very little net energy. It is a non-starter. The use of plastics in wind turbines (as in ALL turbines) is a non-issue and completely misses the point.

Wind energy is a tempting IDEA but a disappointing reality. Wind power is so unreliable and variable that equivalent standby power has to be available all the time, wasting energy. Wind turbine construction is heavily subsidised and the electricity produced (even without allowing for the hidden cost of standby cover) is so expensive it is uneconomical. Power companies only buy wind generated power because they HAVE to by law and they cover the excessive cost by charging us more for ALL our electricity. If it wasn’t for the subsidies (direct grants plus subsidies through us paying more for conventional power) there would be no wind energy in the UK. It is an appalling waste of money that could be better spent on more productive, more economical, more reliable power generation using other technologies.

Tidal power is stronger and totally predictable but receives only a fraction of the subsidy of wind power. Ignoring ideology and looking for a realistic practical solution, we need to be building nuclear power capacity plus clean-burn coal fired power stations with tidal power as a longer term source.

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Is Wind Power Really Green

Ken asks…

green job? question….?

who pays green job worker? and who will create these jobs and pay the workers when the economy is down?

if you know the answer? pls tell me where u found ur information?

Windmill Farms answers:

Assuming that you mean the Green Jobs that the president says will save us, that would be for companies to start up to make things like wind power and solar power. The money is to start a company. It is not for people like you and me–you know—the ones who really need the help.

Joseph asks…

Should the Navy go back to wind-powered ships? Is not being “green” more important than battleworthy?

According to the Administration, we can ill afford the nuclear power anyway:

why not use this historic opportunity to convert the carriers and smaller ships to wind-power?

Not just any waterguns, Daniel. BIODEGRADABLE waterguns…

Windmill Farms answers:

Don’t say that TOO loudly..some environazi will get hold of it and the U.S.Navy will BE a wind-powered fleet again.

Chris asks…

Green issues and power. Who like me thinks that these windfarms are a big investment?

for a small return. And that years down the line we will find them lying idol and will become a blot on the lanscape. Whereas if new builds (houses) had solar panels included into the structure this would be a more energy efficient way of producing the heating needs for individuals instead of lining the pockets of the the Big energy producing giants.

What is your own opinion? Do not be swayed by the majority..your own views please.

Windmill Farms answers:

Wind power is not reliable. Just think of it this way. U are on the operation table and the only power u have is wind power. Quit pushing the idea that it is reliable and it will not tie into other power system without problems. The power station will be rolorcostering to try to stay in sync.

Sharon asks…

How do we know wind power is sustainable or renewable?

Windmill Farms answers:

One thing that the green people conveniently forget about is the effect that thousands of windmills have on the energy content of the windstream.

As large numbers of windmills pull lots of energy from the wind, the wind velocity will slow down. Just like the winds through a forest are much slower than in an open field. The wind energy goes into bending the trees and blowing the branches. If you put a windmill downstream from a forest, you won’t get a very good result.

Now, if you only have a small number of windmills on a hill top, no problem. But if you want to power cities, and have forests of windmills, that can’t help but affect the windstream, and the environment downstream from the windmills. There is no free lunch.

So from that perspective, there is some limit to how effective windmills can be.

And, windmills must be fabricated from materials. There are environmental impacts due to mining and otherwise acquiring and producing these materials, including all of the pollutants given off in the manufacturing process. So, while wind power can be helpful in some applications, it is certainly not a perfect solution.

Putting windmills underwater (turbines) may well prove to be more effective since there’s a much higher kinectic energy content in moving water than in moving air. So you need fewer and smaller turbines to extract the same amount of energy from the sea as you would from the wind.

Hope this helps,


Betty asks…

Is cheap cheap..wind the best cheap green solution…?

If you think about a sailboat then you would agree with me that a really cheap wind EXISTS!
I’m really enthusiastic because there is a great solution in order to use this cheap cheap..wind… (It’s to directly store it with ammonia production. Ammonia is used to store hydrogen). It seems really a great thing!

Windmill Farms answers:

Wind is an excellent clean and very good source of power many small remote communities around the world use it and solar as their only power source. The place I work have two large ones at one of our Antarctic bases which on average produces 40-50% of the stations annual power
and reduces by 10s of thousands of liters the amount of diesel that needs to be shipped in each year.


Although this sort of question usual seems to attract rubbish answers about wind generators stopping the wind and similar nonsense, I saw several a couple a weeks ago that suggested such things would slow the Earth rotation, Scheech! Don’t they teach science in schools any more.

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Uses Of Wind Energy Pdf

Daniel asks…

In which ways can communities use a sustainable manner?

Like water, energy resources, and manage waste sustainably?

Windmill Farms answers:

Let economics and free enterprise be your guide within reason. What is required depends on which community. Http://
one size fits all solutions are doomed to failure. Http://
– Rain water should be owned by anyone who catches it,
not some government entity that will prevent people from using it, and thus force pressure on rivers,
and aquifers. Http://
– People should not be prevented from using small power sources for their homes like solar, wind, small diesel generators, and micro hydro
by insane permitting requirements that forces everyone to use the grids that carry power over huge distances from nuclear a
nd coal plants.

Ruth asks…

Why do people wrongly believe that corn ethanol has a negative energy yield?

When every new study indicates otherwise. And ethanol plants are using renewable sources for power to save money.
Impressive statistics, Matthew. Didn’t realize wind power can be converted to ethanol.

Windmill Farms answers:

Several new studies, including a gigantic one released this year from the US Department of Energy, show the corn to ethanol process to have a significantly larger positive net energy yield than previously shown. These improvements were largely due to greater efficiency modifications and technological advancements at ethanol plants. In some cases, specific ethanol plants have an almost infinitely positive net energy yield due to groundbreaking technologies used to power the plant such as wind turbine technology.

This study published in january 2009 shows the net energy yield of corn to ethanol to be +50% to 80%:

Here are the latest numbers from the Dept. Of Energy, published in May 2009. Go to page 16 of the 20 page summary. In the conclusions section the US DOE concludes that the entire corn to ethanol process yields at least 34% more energy that it takes to make the numbers could be as high as 67% due to rising corn yields secondary to farming improvements and ethanol plant technology improvements. The DOE concludes that corn ethanol is “energy efficient and becoming more energy efficient as time goes on”. They study also concludes that only 17% of the energy used to make ethanol actually comes from fossil fuels:

Lastly, some ethanol plants are producing ethanol and using virtually zero fossil fuels at all. Many are converting to wind power to generate the electricity for their plants. This makes sense for several reasons. First, wind and corn go hand in hand. The areas in the midwest that grow corn tend to be very windy in general. Secondly, the plants see this as a way to save huge amounts of money on energy costs. Thirdly, using wind turbines makes the net energy yield of producing ethanol even more hugely positive. Cornplus ethanol in Winnebago, Minnesota is one such plant that is producing ethanol from almost entirely renewable sources. Here are 2 links to read about it:

And here is one more study that shows corn ethanol yields 67% more energy than it takes to produce:

Now, I want to hear arguments from people that dispute these facts. All 3 studies mentioned above have been published in 2009. Can you provide a newer more current study that shows differently? If you want to argue that the yield is negative please back it up with FACTS and DATA and provide LINKS, as I have done. Otherwise your argument has no weight. If you are going to argue against the net energy yield of ethanol back up your argument with facts, not just your false beliefs. Then again, I guess ignorance is bliss.

Chui, please see my link which addresses the issue you mentioned. We have thousands and thousands of miles of unused land in the US to plant corn and other crops.


Mark asks…

What is the most used form of renewable energy: solar or wind power? (In Maine, USA)?

what is most used form of energy in Maine? Wind vs. Solar Energy? Which produces most megawatts, and which is owned more? No oppinions please, just please have proof. (websites, books ect)

Windmill Farms answers:

Can’t find figures for Maine.

USA-wide, there is far more wind power than solar power:

Over 34,000MW USA-wide, with 175MW in Maine:

They think solar across the US could hit 28GW by 2016:

And that’s with very fast growth and most of that will be in the sourth.

So I’m going to go with wind.

Carol asks…

how much of the UKs energy comes from renewable fuels?

in percentage if possible :)

Windmill Farms answers:

In 2008 it was 5.5% of electricity generation, and 2.4% of primary energy consumption:

The Labour government promised in 1997 that by 2010, it would be 8% of energy consumed (or possibly electricity, the papers were hazy). They will fail, but now they promise 15% by 2020.

However, this isn’t the whole story: providing 1kWh of electricity by wind is the same as providing 3kWh of primary energy by coal – because current coal power stations burn about 3kWh of coal to make 1kWh of electricity.

Powering an electric car with 1kWh of wind electricity is about the same as using 5kWh of petrol or diesel, because good combustion engines are about 20% efficient.

You should probably take this into account!

Susan asks…

What do you make of the new study finding that 31 states could be self-reliant with renewable energy?

A new report from the New Rules Project finds that over 60% of all U.S. states have the renewable energy resources to be “energy self-reliant.”

For example, North Dakota could provide 14,000% of its energy needs with wind alone. 19 states could provide more than their total energy needs with just onshore wind (see page 13). A further 6 states could provide more energy than they need with offshore wind. Alaska could provide for all its energy needs with just conventional geothermal. Almost every state could provide all of its energy needs with enhanced geothermal, although this technology is excluded because it’s not yet mature enough.

Combined, 31 states could be self-sufficient using only current renewable energy technology (see page 23). 11 states could provide over 10 times more energy from renewable sources than they need.

The study also finds that most states could reduce their energy needs by 50-75% by meeting California’s energy efficiency (page 25).

Interesting stuff. What are your thoughts on this study?
Rio, I suggest you look up the definition of the term “literally”. I also suggest you provide relevant answers which don’t contain baseless bashing of the best state in the country.

Windmill Farms answers:

The study also finds that most states could reduce their energy needs by 50-75% by meeting California’s energy efficiency.

That’s the most important part… If we start building all new structures to be net-zero energy and bring everything else up to speed, the cost of the alternative systems would be greatly reduced by the smaller capacity needed.

As a green builder of net-zero energy homes, I have people waiting in line while other builders are going out of business building the same old cheap crap!

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Wind Energy Definition

George asks…

Would it be an idea of building a wind turbine on a car?

Say you have a hybride car and would build a wind turbine on the roof of it (or build it inside the car so it will catch a lot of wind) to gain some electricity back. Could this be an option to reduce the nett energy consumption? Why would or wouldn’t it be?

Windmill Farms answers:

You could indeed make the turbine generate electrical energy which you could store in a battery. However, there’s a catch. By definition, turbines resist the wind (if they did not, they could not rob the wind of any energy). This means that any energy you capture in the battery will necessarily translate into increased wind resistance for your car, which makes your gas mileage drop (basically, reduces the amount of energy you can get out of a gallon of gas). So, in effect, what you are essentially doing is taking energy out of your car’s driving force (the chemical energy in the gasoline), and converting it into electrical energy in the storage battery); and meanwhile your car’s mileage will drop accordingly. The law of conservation of energy says that the energy you store in the battery cannot exceed the extra chemical energy used up by buring the gasoline to overcome the wind resistance. So in the end you are not reducing your net energy consumption. And in fact, you are using up MORE energy; because the 2nd Law of Thermodynamics says that whenever energy changes form (e.g. From chemical to electrical), at least some of it is lost from the system, in the form of heat.

Jenny asks…

how does a wind turbine generator work?

I think I’ve designed a new wind turbine and I need to start thinking about the generator part. How does an electricity generator work in this case and where might I procure one in the UK?

Windmill Farms answers:

Well, by definition a turbine creates shaft work, which can then be converted to electrical energy through electromagnets.

Sandra asks…

If something is not in motion, can it still have mechanical energy?

can someone explain to me but make it simple

Windmill Farms answers:

Energy= the ability to move something (work), so if a boulder is on top of a mountain it has to have energy or else it wouldn’t be able to move you when the wind blows the boulder towards you, this type of energy is called potential energy, kinetic energy is the opposite of potential energy, it is the energy that moving objects have mechanical energy= potential energy + kinetic energy, so by definition still objects must have mechanical energy.

John asks…

Does anyone know anything about solar energy?

i don’t know if solar energy and solar power are the same thing? are they?

1.) How widely used is this form of energy (in usa) . (example: Provides 40% of total electricity in the us.)

2.) How economical is solar energy when compared to other sources?

3.) What are the environmental factors which must be considered when using solar energy? (at least 2)

i will reward the best answer with all stars so please help me. dont forget please CITE your source its very important that you do so(: please and thank you.

Windmill Farms answers:

Solar power usually refers to making electricity from the sun. Solar energy may refer to this and also sometimes using the heat energy from the sun. Thermal solar collectors may use solar energy to make solar power.

Solar energy is only beginning to be explored in our society. In other societies (ancient Greece for example) there were laws to prevent one person from blocking the sun from the land of another as the sun was important for heating. The sun’s energy stored in chemical bonds has been very common in our society. Oil is king. This has marginalized direct solar energy use. The amount of Solar energy in our society depends upon what you are including. Direct Solar? Wind? Biomass? Hydro generation? Here is one site that adds it up to 13%:″>

2 the economics of solar is also subject to definitions. Real cost or cost including politically gained subsidies. Gasoline may cost $3.00 at the pump but estimates of its real cost are from $10 to more than $20. Nuclear power is also heavily subsidized. Solar is just getting into the game and is taking time to get its political markers in place. When it comes to efficiency solar is far more direct and has some distinct advantages. Http://

3. Direct Solar energy and renewable solar energy is substantially more eco friendly than using fossil solar energy. Shading environments with solar collectors changes environments this may have effects to be considered. Some large scale solar power installations need water in environments where this is scarce. Wind generators may have an adverse effect on flying wildlife. And hydroelectric dam may add unusual pressure on the Earth’s crust. Http://

William asks…

How does energy work?

How does energy work? I just want to know how

Windmill Farms answers:

It simple.
We use energy to do work. Energy lights our cities. Energy powers our vehicles, trains, planes and rockets. Energy warms our homes, cooks our food, plays our music, gives us pictures on television. Energy powers machinery in factories and tractors on a farm.

The definition of energy is: the ability to do work
some example of energy are:solar energy,Nuclear Energy,Wind Energy,electricity,Fossil Fuels etc.
Hope this helps :D

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Renewable Energy Group

Nancy asks…

Science h/w renewable energy?

Renewable energy

We have to do a task about suitable renewable energy for the uk we have to work in groups of 5 s and we have to do a 5 minute presantation (speaking) to the government committee (our class).

Our group decided to do wind power. The questions are..
Why we have chosen this type of renewable energy source
Where it would be placed in the UK?
The start up cost( of a wind farm) and projected income that the resource can make by selling to the national grid
How it works (how the technology work)
The issues and benefits.

Thank you!

Windmill Farms answers:

Here is a very useful website:

Good luck with your interesting project.

John asks…

Renewable Energy Research Paper?

I have this research paper and my thesis is “Nuclear energy should be replaced by renewable energy” The research is due very soon and I have finished researching nuclear power but I am having trouble with renewable energy facts because the topic is broader and not just focused on one type of renewable energy, at least that is what i assume.

Does anyone have any recommended reliable websites that would be good for this topic or do you have any information about renewable energy that you could share with me? Thank you for the help.

Windmill Farms answers:

Sarah, I’ll have to say I’m surprised there aren’t more comments here after 4 days, this has become a fairly charged issue the last few years. I don’t think you’ll find a website with a discussion of nuclear vs. Renewable directly, but there are some really good non profit groups doing research in the renewable area, and non that I’m aware of in nuclear. That might say something to your subject in itself.

Since about 1970, nuclear power has been touted as cheap and endless. Turns out it’s neither. It’s a little like the oil companies saying that they can extract oil from the artic without making a mess. It’s true, they can, but they never do. The real problem is in human nature. We legislate how these tasks are done, but in the end, the people that are hired, trained and shipped to these remote locations are left to make their own decisions, and as a race we tend to take the path of least resistance. So lots of waste products end up in the ground and ocean. What people like me suggest is we find a way to do things that will be easier for people to do the right way, and let human nature take it’s course.

In virtually all places in the globe where nuclear power is heavily used, the utility prices are higher than most other places. Chicago is a great example, with 13 plants operating, electricity rates are closing in on 25cents per kilowatthour (KWH). In the Pacific Northwest, it’s 1/3 that price, an area that is heavy on hydro power, one of the renewable sources of energy. The same thing is true in parts of Europe, like France and England which are heavily invested in nuclear, and are now looking into wind, oddly enough because it might be less expensive.

Wind power is a great story, it is expanding over 30% each year right now, and it’s cost is on par with coal power now, historically one of the cheapest sources of utility power, that’s why there are so many farms being installed today. Some people argue that to power our country, we would need to cover the entire Atlantic Ocean with offshore turbines. Actually, there is enough wind power in North and South Dakota to power the entire country, but here is where the real advantage of renewable energy shines through. It doesn’t make sense to put all the wind turbines there, because we would then have to ship all the power over a massive grid to the rest of the cities. Well it turns out the only way to make coal, nuclear or oil fired plants work economically is to make them large, then ship the power on large grids all over the state. Renewable energy is spread pretty evenly over the middle third of our globe, where most of the people are. So we can put a dozen or so wind turbines around the outside of major cities, and a few solar farms in the desert, plus the hydro power we already have in most of our states, and we dont’ need a large grid. A small one to connect using areas to producing areas to accomodate local shortages and surpluses is perfect, like the grid we have now. Each time we add a little more power to one location, it reduces the load on the grid as a whole by supplying some power where it is needed.

The best way to harness these advantages is to put small solar arrays or wind turbines at remote homes and businesses then intertie them to the grid. This eliminates most of the load on that end of the street, but the power companies still act as intermediary, buying excess solar from one house, selling it as utility power to the next. We actually live in a home that does this now, and we love it. Most our power comes from our small solar array, and the rest from the power company, and our bills average about $5 per month.

I could go on with other environmental benefits and so on, but I think you get the picture. For more info, try going to the sources below and do some more research yourself. Good luck Sarah, and take care, Rudydoo

Linda asks…

Renewable/Alternative Energy Majors?

I’m trying to decide on a major and all I know is I want to someday contribute what I can to the development of clean energy. I’m told that physics is a useful degree for that sort of career. Anyone know if Engineering Physics or just a solid Physics degree are good choices? Is one better? Are there other majors that would help more?

I know chemistry is a solid choice for bio-fuels. I like chemistry, i’m just not convinced bio-fuel is a good pick.

Windmill Farms answers:

I did a physics degree followed by a physics masters with solar power research. My mate did the same, except that his masters project in supercapacitors for energy storage.

He now has a job with Centrica doing in house IT and may well end up working on smart grid renewable stuff. I would have been able to go into solar research or get a job with a power company pretty easily according to people in my research group but I decided to go do climate science instead.

A physics degree is a way in, but you’re more likely to end up either in R&D or working with IT and the likes with a physics degree. Electronic engineers are more likely to be involved in the design of power stations and so on, although both should be adequately qualified for a renewables job!

Tbh, most majors can get involved in renewable energy; the companies need salespeople, IT technicians etc as well. Physics, chemistry and engineering are probably your best bet for real involvement with the tech.

Sandra asks…

I’m doing a debate on renewable energy….?

…and I’m kinda stuck. My group has been assigned to find the advantages of solar power versus wind, hydroelectric, and nuclear. Only I can’t really find anything! If you could maybe offer some advantages yourself or give me a website, it would be GREAT!! =)
help me please!!!

Windmill Farms answers:

It depends greatly on location and funding which resource is the best. In the US for example, there are many great location to put windfarms: Along the coastal regions and near the Great Lakes among other places. It is wonderful for Americans because they can afford the initial investment of building wind energy systems and they have many experts within the country who are able to make any necessary repairs to the windmills. In third world countries however clean energy is not subsidized by the government and the towns and villages are too poor to purchase even the smallest windmills. Think about it, in order to set up and run a windmill you need a turbine which is very hard to transport and expensive, a battery bank to story the energy which is probably the most expensive part of the whole system since wind does not blow fast enough to run the generator 100% of the time, and as I already mentioned a generator to produce mechanical energy that can be converted into electrical energy. Plus poor countries cannot afford to hire people to work on the windmills if they break and people like Engineers Without Borders who train locals do not understand that once a local in a poor village has that kind of technical training the person will usually leave to get a job where he or she can make more money with such skills and send money back to his or her family. In such countries a more robust (simple, reliable, and safe) and accessable method for energy generation is desirable. Another thing about windmills is that they are only guarenteed for 20 years and then they have to be replaced. I lived in a town called Hull in MA that got 12% of their town energy (as of 2005) from wind power and the town saved so much money, even though the wind was not always fast enough to efficiently run the generator and produce electricity. If you are interested you should check out the Cape Wind Project’s site. Another interesting field of research here does not come from turbines at all but from a lot piece of material that will vibrate in the wind and produce energy without the concerns of killing birds or hitting flying vehicles.

Many experts believe hydrogen to be the one energy source that will revolution energy but yet there is still not an efficient method of producing the hydrogen. The idea is fantastic: hydrogen is the most abundant element in the universe, and if humanity could harness its power we would have as much energy as we needed and we could get it from the ocean without polluting the environment. The generation of hydrogen now however generally comes from electrolysis (H2O -> (1/2)O2 + H2) and steam reformation which creates green house gasses. So much for clean energy. In addition, hydrogen is also hard to store and extremely combustable. After you consider all of these facts remember that you need pure water to run the fuel cells. Hydrogen is unquestionably renewable but the question here is whether or not it is desirable. Don’t think I am down grading the prospective usefulness of hydrogen. I am just say a whole lot more research and development is needed to make it competitive with other sources of energy generation.

Nuclear is wonderful until you realize that in the long run it is very expensive (many argue that such plants never pay for themselves) and there is nowhere to store the waste that will satisfy everyone. In 1995, 32,000 metric tons of nuclear waste was produced. In 2015, the number is projected to be 75000 metric tons. But where does all of that waste go? Some of it was set aside to be buried in a mountain in Nevada but the state didn’t want it there so it had to be disposed of elsewhere. We could shoot it off into space but you know how much pollution that would produce getting it out of our atmosphere?

Solar panels are the most expensive means of energy production used today(at about $3000 per kilowatt for the panel). These photovoltaic cells are also difficult to produce and easily stolen off of houses particularly in developing countries. People are working on flexible cells that could generate the same electricity for a fraction of the cost (these are not produced with silicon).

Passive solar however is probably the easiest method of producing renewable energy. The heating of water for to use directly or to pump through the walls and floors of a building for heating purposes is amazingly efficient. Other obvious ways of utilizing passive solar energy are the placement of windows on building and the colors and materials used that could prompt or inhibit the absorbtion of energy from the sun.

Another fact that you might want to look at is how many watts does each type of energy generally produce and whether or not that type of energy is good for comercial, domestic, town, city, or rural uses.

I hope this helps ;)

Richard asks…

Why does the koch bros americans for prosperity front group oppose renewable energy in colorado?

olorado Gov. John Hickenlooper has signed legislation that will double the amount of energy that his state’s large rural electric coops and the utilities that provide them power must get from renewable sources to 20% by 2020.

Enactment of the legislation represents a major victory for clean energy advocates and Colorado’s rural economies, and came despite a massive disinformation campaign run by the state chapter of Americans for Prosperity that is backed by right wing oil billionaires David and Charles Koch.

Windmill Farms answers:

What’s stunning about the right?

They’re ready to suppose that democracy favors the weak, the needy and the poor, that these massive group of people bias the results leftward… So, when you’re poor, you’re acting because of the monetary incentive. However, when you are a super rich man who funds right-wing movement, you’re not being interested by any gains. You’re being kind to the rest of the population, objectively and neutrally informing them.

If poor people vote to get welfare, at least be logically consistent: the Koch brothers and their mates are not in politics for the sake of promoting their beliefs or your well being; they’re there to make money — and guess in the end who benefits the most from it? The poor or the rich? The rich.

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