Wind Power Facts

Ken asks…

How can I make residential wind power?

I want to make residential wind power for my home.

I live in a built up area so I cannot have one of those massive things spinning around in my backyard.

I want to make one of those smaller windmills I always see on roof tops? Anybody have some instructions for me?

Windmill Farms answers:

I got a simple set of instructions and in fact built three of these after I was so satisfied with the first one. I got my schematics and detailed instructions from http://www.ebooksreviewed.info/earth4energy and was on my way in no time, check it out if you’re interested.

John asks…

How can a wind powered vehicle go downwind faster than the wind?

Here is a video of a vehicle that is wind powered and can go downwind over twice as fast as the wind.

Best explanation.

You need to analyze how it works at below the speed of the wind, how it transitions from slower than wind speed to faster than wind speed and how it travels faster than the wind.

This is a gedanken experiment. Prefer independent thought over looking something up.
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Good start. Sorry, I realize that the cite I gave you did not include a schematic.

The propeller is tied into the drive wheels like this: http://blog.makezine.com/upload/2010/11/downwind_faster_than_the_wind_black/windCart_2.jpg

Two things to consider

1. You are correct that when the vehicle is going at windspeed, it generates no power

2. Watch the propeller in the video and both when traveling below windspeed and above.
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Hi John:

That’s a pretty cool vehicle you got there. Thanks for showing up here.

Based on the schematic, I figured you’d have a hard time transitioning through the at wind speed zone. Just seemed to me that the blade was using energy from the wheel to pull the vehicle through this transition and that later on, when in a headwind, it would be transmitting energy to the wheels to power the vehicle. (You are also transitioning from vehicular drag being a power source to it being drag) My presumption was that it would be normal variations in wind speed would be enough to get you through.

Guess I’ll have to read up on your project instead of trying to reverse engineer it.

Thank you again.
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As an addendum, I once ran across a brainteaser about whether a boat with a wind turbine for a sail which powered a propeller below could sail directly into the wind.

My conclusion was that it could. There are overlaps with your project.
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Al P., some of the confirming data is public. See: http://www.fasterthanthewind.org/2010/05/testing-graph.html (You can click on the graph to enlarge).
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John, I found my thinking error and now agree with you that you would have a lot of power at windspeed. My initial thought was a design that would do great going up wind but would suffer at and below windspeed. (I was using the blade as a turbine to power the wheel instead of the other way around). I saw that you are planning an upwind attempt next summer. Good luck.

You must do a regular google search to find discussion (including this one) related to your vehicle.
Lastly, to anyone following this question, it comes down to the basic principle of aerodynamics. If the propeller is generating more lift than total vehicular drag (and efficiency losses), then you can channel the lift into powering the vehicle.

With this vehicle the lift is channeled into thrust of the propeller (and the drive wheel siphons off some of the thrust energy to spin the propeller). But I suspect that for an upwind vehicle, the lift is used to spin the drive train thereby using the wheel as the primary drive.

Given the efficiency of some of the propellers for wind turbines, I am not surprised that this vehicle can go so fast.

Windmill Farms answers:

You say this is a ‘gedanken experiment’. In the spirit of that experiment, it wouldn’t be fair for me to submit an answer in this case as I am the one two primary designer/builders of the vehicle in the video you open your question with.

I would however like to say that point #1 in your “Additional Details” section is incorrect as it relates to our vehicle. The Blackbird is still harvesting energy at exactly windspeed and generates copious amounts of thrust from that energy. That is how it continues to accelerate to a speed much greater than wind speed.

I know this is not a discussion forum, so I will not explain further unless asked.

EDIT:
Sythian, I am happy to explain it, and I’ve done so countless times but I don’t think that’s what the originator of the question had in mind when he asked for people to post their answers — I believe he posed it as more of a brainteaser and since I have the answer to the brainteaser it’s not polite to shout it out right at the start.

It’s not perpetual motion, and if you believe that it can be done on an angle to the wind, then you should be able to figure out by watching the Blackbird videos how we do it going DDW (hint: not all of the Blackbird is going DDW).

Our construction blog: http://www.fasterthanthewind.org
Explanations: http://dwfttw.blogspot.com/

EDIT #2
AI P — NALSA placed and observed 18 recording sensors placed on the Blackbird itself, on a chase vehicle and on the surrounding desert floor for the world record runs. This data was used to ensure the process was indeed ‘steady state’ and not some ‘playing tricks with the wind’ stunt. NALSA will happily share data with you — just contact them through their website. And thanks for the kind words — much appreciated.

@AI P — Yes we have all the data, but it does nothing for the project’s credibility for *us* to release data from the record runs. We’ve made that mistake before and simply been accused of screwing with the data before releasing it. There is a verfiable chain of custody if you get the data from NALSA because they made sure we didn’t screw with it when it was collected. NALSA has data they formatted available on their site via download link, and I know for a fact that if you wish they will also give you raw data upon request.

@Sean Rupert:
No Sean, there is no computer control necessary or used. In fact we ran the prototype with a fixed pitch head with no change in airfoil angle at all from dead stop to well over 2x the speed of the wind.

Http://www.youtube.com/watch?v=EEuAqq8FINw

@Sean Rupert:
I already did.
“Explanation: http://dwfttw.blogspot.com/”

Daniel asks…

do you think wind energy is viable if the government decides to stop extending subsidies?

Energy from wind power is becoming an increasingly significant source of energy, considering that the price of oil is getting dearer. This is especially so for oil-deficient developing nations like India which meet their energy needs by importing oil. Providing facts and figures, analyze the opportunities and challenges that wind energy companies face in setting up wind farms in India.

Windmill Farms answers:

I live close to an area (in Ontario) where one phase of a wind farm is up and running and the next phase is scheduled to start shortly. Total PLANNED capacity is about 160MW. The latest figures show that Ontario as a whole will eventually have in place about 500MW of planned wind power capability.

Sounds fine, except for a couple of important points:

The wind farm near me is currently running at about 20% of capacity. In other words it’s only producing power 20% of the time. If that’s extended to all wind projects, it means we’ll finish up with a total of about 100MW of available power.

How much is that? By comparison, a single generator at Nanticoke GS (on Lake Erie) or Lambton GS (near Sarnia) can produce 500MW continuously. Nanticoke has 8 generators, Lambton has 4. Ontario’s average requirement is for something in the order of 20,000 to 25,000MW (20-25GW) So go figure how that measly 100MW is going to help.

Consider the blight on the environment of all these unsightly monstrosities. The damage to bird life. The noise (yes, there’s noise!). Do we really want to continue installing wind generators when they produce so little power, yet make a totally negative impact on the environment? Remember that they can only produce power when there’s wind (at sufficient velocity) to drive them, and regardless of the figures that the met office produces, there’s not sufficient wind to keep them turning continuously.

The only sensible answer is to our power needs in the future is nuclear power. It’s proven to be safe for one thing and has little impact on the environment. Or clean up the coal-fired stations (and as a retired instrumentation engineer, I can tell you categorically that it can be done very effectively and efficiently).

Sandra asks…

do you think wind energy is viable if the government decides to stop extending subsidies?

. Energy from wind power is becoming an increasingly significant source of energy, considering that the price of oil is getting dearer. This is especially so for oil-deficient developing nations like India which meet their energy needs by importing oil. Providing facts and figures, analyze the opportunities and challenges that wind energy companies face in setting up wind farms in India.

Windmill Farms answers:

Hi there, I work for one of the world’s leading renewable energy consultancies. While my background is more technical in nature (I’m an engineer), I’ll take a shot at answering your question.

Wind energy certainly is viable in many parts of the world without subsidy. We came dangerously close to finding out exactly how viable it would be this year in the U.S., when an extension of the Production Tax Credit (PTC) was extended into 2009 at the last minute as one of the “sweeteners” that got the $700 billion Wall St bailout passed.

Http://www.nicholas.duke.edu/nicholas/insider/thegreengrok/the-700-billion-bailout-bill-goes-green-not-quite

The current subsidy for wind energy in the U.S. Is PTC, which is a tax credit currently equal to 2 cents per kWh. The price for electricity varies significantly by region, so some regions are more closely tied to the PTC than others to make the economics of a wind project work out. For example, the price for electricity is only about 4.5 cents per kWh in the Midwest (e.g. Oklahoma, Kansas, North Dakota), so that extra 2 cent per kWh makes a huge difference. In other parts of the country (California, Hawaii, New England), the price of electricity is over 10 cents per kWh, so the 2 cent tax credit is relatively less valuable there.

The bottom line is that there are several places under development now in the U.S. That are good enough to justify being built without the 2 cents per kWh tax credit – these select locations are very windy, close to a transmission line, and/or in areas with high electricity prices. Without the subsidy, the growth of wind energy in the United States (same goes for the rest of the world, to my knowledge) would be severely affected. Thousands of people would be laid off, a significant portion of projects would be canceled, and we’d all go back to burning lots of cheap and dirty coal, nuclear, hydro, and finally natural gas to fill off the balance of our energy needs.

Regarding your question about oil imports in countries like India, I think you might be slightly misguided. Wind energy does not provide fuel for transportation, just electricity. Until we have a way to develop the hydrogen economy (http://auto.howstuffworks.com/hydrogen-economy.htm, convert electricity to hydrogen fuel, distribute it through a nationwide infrastructure we don’t have, and put it in cars that are currently cost-prohibitive), we will remain addicted to oil. The alternative to oil (for now) is ethanol. Especially in places like Brazil, which have plenty of land and a great climate for growing sugar cane ethanol rather than the subsidized corn ethanol we produce here in the U.S.

Wind energy is the cheapest form of renewable energy currently available, and it will get cheaper in the coming years as the credit crisis corrects what has been a massive seller’s market for wind turbines in the last few years. Competition in wind turbine manufacturing is up, and the cost of steel (the 80 m towers) and cement (the massive foundations) is down. These factors will lead to wind energy becoming cheaper in the next few years. Wind energy can be cost-competitive with natural gas, offsetting our need for this finite resource and (hopefully) lowering prices for consumers. That’s the long-term benefit of the subsidy – get the industry built up now so we will be well set for a future of increasingly scarce oil and natural gas, which will be imported from unstable regions of the world.

Lisa asks…

Does it make you feel nice and warm inside to see wind turbines across the landscape?

Consider that if there were no government subsidies, wind turbines would never be considered. Look at windwatch.org for the facts on wind power.

Windmill Farms answers:

No they make me dizzy

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