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12 Small Windmills Put To the Test In Holland
tuna writes "A real-world test by the Dutch province of Zeeland (a very windy place) demonstrates that small windmills are a fundamentally flawed technology (PDF of tests results in Dutch, English summary). Twelve much-hyped micro wind turbines were placed in a row on an open plain. Their energy yield was measured over a period of one year (April 1, 2008 — March 31, 2009), the average wind velocity during these 12 months was 3.8 meters per second, slightly higher than average. Three windmills broke. The others recorded ridiculously low yields, in spite of the optimal conditions. It would take up to 141 small windmills to power an average American household entirely using wind energy, for a total cost of 780,000 dollars. The test results show clearly that energy return is closely tied to rotor diameter, and that the design of the windmill hardly matters."
rather than 141, if you used the Montana.
and even argued that sea based windmills would be inefficient recently (I think they will be attacked for their parts and be big targets if there was a war and I think maintenance in a high saline environment will be higher than they think)...
I do have to point out that
* any supplemental power comes off of the most expensive part of your bill (I pay more over 250kwh, and a whole lot over 750kwh).
* the more windmills we build, the cheaper it will get to make them.
Still- I think nano-solar type approaches are the most likely to work out.
She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
Wow, reading more I see how blatantly WRONG this summary is. There was one windmill that two of them would power a whole house. The "Energy Ball" one is the POS that takes 47 windmills, the rest are a lot better.
Bigger is better but still expensive in the short and mid term, and only windy areas will benefit from them.
Troll, n. - Someone who disagrees with me
Apparently it does matter, and these were obviously very poorly designed if three of them straight up broke.
3.8 meters/second average is not a windy area, infact it's a Class 1 wind speed. There are many places in the U.S. that are Class 3 or better, and you'd get much different results from those areas.
... What will they think of next?
I am not an aeronautical engineer, but I'd guess energy output is roughly proportional to either wind speed times radius, or wind speed times radius squared.
So yeah. Small windmills which can only use a small amount of the wind are not going to harvest as much energy as a bigger windmill.
But the electricity needed to power the average American household would power a medium-sized Dutch city, right?
Get your own free personal location tracker
Why don't the Dutch install tidal turbines in their fields instead, and wait for their country to flood.
Oh I kid, I kid
It would take up to 141 small windmills to power an average American household entirely using wind energy...
I think this sais more about American household power consumption than it does about small windmills. Doesn't it?
I think it's a little sad and I would love to see a power-meter that shows exactly how much power you use when you use it. I think that would make people think.
Also it's a little amusing to read this site on how "bloated" KDE and Gnome are, or how bloated the linux kernel is, but still people use their terrible inefficient cars and houses that are energy-hogs.
Why isn't everyone here trying to make their home and car as efficient as comfortably possible? It's the "techie" thing to do.
And the tech is already available.
Remember that the cheapest energy unit is the one that you don't use.
You are not entitled to your opinion. You are entitled to your informed opinion. -- Harlan Ellison
The windmills seems to have been erected very close together. This may cause them to interfere with each other through turbulence. Also, some of them did fairly good. The Skystream and the Montana doesn't seem to be a total waste of money.
GAAH! MY PRINTER IS ON FIRE!!! PUT IT OUT! PUT IT OUT!
Maybee zie posteer kann no sprechen oder reeden die Dutchenzeelandspache so gut.
And it had 5 meter blades, which are way to big for the average rooftop.
Because it is cost prohibitive to do what you seem to be demanding.
There are two very simple scaling laws at play here.
First off the wind power intercepted goes up as the square of the rotor length. So larger is better, a lot larger is a whole lot better. You also get the free benefit of stronger winds as you have to raise the center point as to not hit the ground.
Next the power goes up as the CUBE of the wind speed. So it really pays big to find a real windy spot.
So your basic $30,000 small, low windmill placed on your typical house are real big losers.
I was going to use my mod points to mod you informative, but when I got to the web site I got this little conundrum:
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Subscribe/Join AAAS or Buy Access to This Article to View Full Text. The content you requested requires a AAAS member subscription to this site or Science Pay per Article purchase. If you already have a user name and password, please sign in below
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If you provide a link, please at least make it one where I don't have to pay, or provide the full text here.
As it is I can hardly determine if your thoughts about the EPA are a troll, or true. Try again.
Life is a great ride, the vehicle doesn't matter
So the environmental movement is worried about the environmental impact of burning all these fossil fuels. There may be a new way to switch from using oil to coal. This does nothing to help the environment, so no the environmental movement is not going to see it as a solution.
It's physics 101.
Capturing a larger cross-section of moving air is more efficient.
The reverse is also true (generating thrust):
Turbofan engines are more efficient at lower air-speeds than straight turbojets.
Moving a small amount of air at a higher velocity will create more wasteful eddies than moving a larger cross-section of air at a lower speeds.
Helicopters are the extreme case WRT aircraft.
You need a lot less power to make a helicopter hover than a ducted-fan or jet VTOL aircraft (like the Harrier or the JSF).
It reminds me of people who are surprised that electric cars / hybrids take up the most energy when they accelerate.
Duh, that's when you're actually gaining kinetic energy.
In cruise, you're just fighting drag (air) and friction (road).
I don't think the EPA has any say in whether most people want to put a windmill on their property or not. I know people that have looked into putting one or more windmills on their farm (it turned out they don't have enough wind to make it worthwhile), and they didn't run into any EPA restrictions.
Neighborhood associations and local (city,county) regulations might be a different story, of course.
[b.belong('us') for b in bases if b.owner() == 'you']
There is original research posted to Slashdot all the time, mostly in the field of computer science.
If there is enough data in the article to draw your own conclusions, then there is enough to discuss. This is a discussion site. If Slashdot only posted agreed-upon facts, then we would all just sit here with our dicks in our hands.
What the fuck is wrong with you people lately? This isn't wikipedia. We don't need anything filtered for truthiness by the retards responsible for that site.
"I assumed blithely that there were no elves out there in the darkness"
windspeed cubed and radius squared
not to mention the effect of turbulance on o/p
It's best to put these on a tower anyway, so that they're up above all the turbulence created by stuff on the ground. So the blades are going to be a long way from your roof whether they're 2m or 5m long (as long as you care about the machine actually generating some power, that is).
[b.belong('us') for b in bases if b.owner() == 'you']
The Skystream produced 2'109 kWh per year, which makes around 422 Euros at the current price of 0.2 Euros per KWh (do some googling...). For an investment of 10'742 Euros, this makes a return of 4% per year.
With the current economy, this seems like a good investment...
There are investors working to put a couple of commercial wind towers up a couple miles from here. A woman with property in the area has been sending out monthly newsletters slamming wind power (infrasound, weird electrical effects, property values, etc.). Her agenda isn't going to stand up to the wind towers that just started operating 15 miles away that people can just go look at though.
Nerd rage is the funniest rage.
Dutch experiment proves theory doesn't map to practice. Film at 11 ...
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
This has to be the worst summary ever. Please take the time to look at the article and do the maths yourself.
"Some days even my lucky rocketship underpants don't help."
Repeat after me: slashdot is not wikipedia.
Original research must appear somewhere in journals and the like. When it appears it becomes news. Slashdot is, guess what? news for nerds.
Now someone please mod the parent down.
Windmills do not work that way!
I bet you don't live in a location that frequently experiences >90% humidity and >100F temperatures at the same time in the summer.
A way to burn more hydrocarbons?
I think the environmental movement would be right to scream in horror at this prospect.
Haha, this should be modded funny if only for the taser comment.
To parent and sibling above:
There's usually a link to a news or scientific article somewhere. Here's a poster personally drawing conclusions as "ridiculously low yields", what good does that do? So I disagree: this is not news.
When I spent time in Germany, I noticed that their homes really are quite similar to ours. The real issue was that EU has MUCH nicer climate throughout. With that said, I would like to see a comparison of electrical/Gas usage of a HOME, as opposed to a region. The reason is that most places try to compare regional uses which adds in manufacturing as well as travel.
I prefer the "u" in honour as it seems to be missing these days.
"Free energy devices are out there (such as the "Joe Cell") but are being ruthlessly suppressed by the corporate elite because they would lose control of the populace"
They cannot be suppressed if the inventor makes them instantly available under appropriate Free and Open licenses via the internet.
Youtube videos prove nothing Inventors should actually build a working model and offer it for testing by neutral third parties, and should furnish specific plans so anyone wishing to build their own example and test it in public can do so.
"This post is an artistic work of fiction and falsehood. Only a fool would take anything posted here as fact."
On the Renewable Energy website OliNo there is an article Test results small wind turbines website with some more background on this test. The first test results show that a PV system (Solar Energy) is more cost effective than these small windturbines. The Dutch article, which is more up-to-date, show also the last measurement results of the windturbines (11 months of data). The conclusion is the same. However, it was found out, that an official wind measurement station of the KNMI only 14 kilometers (8.8 miles) away form the test site has an average windspeed which is twice of of the test field. This could explain the low yield of the windturbines.
Uhhh I know you think you have it the worst but when it comes to costs.
heating > cooling
Morbo: Direct your attention now to the African turtles seen here migrating to cooler homes in Holland. Morbo wishes these stalwart nomads peace among the Dutch tulips.
Linda: I'm sure those windmills will keep them cool.
Morbo: Windmills do not work that way!
Doesn't matter, the EPA would never let you build private windmills.
Windmills have been long present in the rural USA. The EPA has never been involved before.
not in Holland. Holland is the combination of North-Holland and South-Holland, both provincies of the Netherlands. The Netherlands is the country as a whole. The Kingdom of the Netherland is the Netherlands plus the Netherland Antilles and Aruba. Zeeland(Sealand) is a provincy seperate from Holland.
Knowledge is power. Knowledge shared is power lost.
I plugged the numbers into a spreadsheet; it looks like power output is proportional to roughly D^2.5 (probably closer to 3 than to 2; I didn't do a best fit analysis). Cost is proportional to somewhere between D and D^1.5 (closer to D).
Note that the area is proportional to D^2, so bigger windmills actually extract more energy from the same amount of airflow.
Basically, the 1 meter windmill is a toy. It would be more practical to hook up a generator to a bike or rowing machine and use a battery or flywheel to store the energy -- that way you'd at least get some exercise out of it.
Misschien kan de man niet Nederlands heel goed spreken of lezen?
The one that did the best was only 330cm in diameter the blades are half as long. diameter does not equal radius, even in german. Also the test results, if true, the best windmill would power 75% of the electric needs of the building where im living (3 apartments)
All misspellings and grammatical errors in the above post are intentional and part of my artistic expression.
If this is real... then its real cool.
;)
http://www.youtube.com/watch?v=RRXRUFrxKAQ&feature=related
I know that where I live, if I had one of those, I wouldn't need to be plugged into the grid (most of the time at least.)
And there are so many other hobbyists who have vawts on youtube - interesting stuff. The dutch just took the wrong approach to it
many parts of the world (eg middle east) run water tubing though black panels on the roof for heating hot water. Should be a simple change to plumb water lines feeding your tank under the panels. Could even rig an auto valve for daytime flow only.
Moving a small amount of air at a higher velocity will create more wasteful eddies than moving a larger cross-section of air at a lower speeds.
Although true, that's not the reason turbofans are more efficient.
The reason has two parts.
Since aircraft have an unlimited supply of fuel mass, they can go quite far in terms of optimizing for energy efficiency. Within practical limits, of course. The exhaust has to be faster than the intake, for instance.
I reckon that it was the guy's hand that was moving.
If this was really capable of generating energy you would have seen a video of a static setup driving a small dynamo - or something similar.
Agreed. Wildly inaccurate summaries from authors drawing their own conclusions that aren't based on anything resembling reality is nothing new, and certainly isn't news.
Producing Transportation Fuels with Less Work
Diane Hildebrandt,1 David Glasser,1 Brendon Hausberger,1 Bilal Patel,1 Benjamin J. Glasser2
The long-term strategy for reducing emissions of carbon dioxide (CO2) and other greenhouse gases is to replace fossil fuels with renewable resources. In the short term, liquids derived from fossil resources will be used to power transportation, in part because liquid fuels have an established production and delivery infrastructure as well as high energy density. Liquid fuels are overwhelmingly derived from increasingly scarce crude oil, and it would thus be beneficial to make liquid fuels from other sources, such as coal and biomass (1, 2).
One reason why liquid transportation fuels are derived from petroleum instead of coal is that converting coal into liquids is much more energy-intensive. Thus, substantially less CO2 is released in the production of a gallon of gasoline derived from petroleum than in the production of fuel from coal-to-liquids (CTL) processes (1). The carbon atoms in coal are largely bonded to one another in graphitic networks, and breaking these bonds requires a large energy input. Energy is also needed to supply hydrogen to the process. We outline reaction chemistry and processing designs that could dramatically reduce these energy inputs and minimize the amount of CO2 emissions that would be emitted or mitigated by other costly strategies, such as carbon capture and sequestration (3).
There are many methods that convert carbon-rich sources into liquid fuels, including pyrolysis, direct liquefaction, and indirect liquefaction, which proceeds through gasification such as the Fischer-Tropsch (FT) and methanol-to-olefins (MTO) processes (2, 4). Of these, the FT process
3C + 4H2O -> 2CO + 4H2 + CO2 -> 2(-CH2-) + 2H2O + CO (1)
(where CO is carbon monoxide and -CH2- represents the alkane products) has been successfully implemented on the largest scale industrially (2, 5) but is very inefficient in that a large part of the carbon fed into the process ends up as CO2, either directly or indirectly from fuel consumption for heating the reaction (5). However, FT technology gasifies the coal so that unwanted ash, heavy metals, and sulfur can be removed (2).
To identify more efficient ways to run chemical processes, theoretical tools have been developed that can look at the industrial plant as a whole (6-9), even at the level of rethinking the reaction chemistry. These tools assess what would happen if we could operate the plant as efficiently as possible (that is, near thermodynamic reversibility).
For example, thermodynamic principles have been applied to examine the production of molecular hydrogen (H2) by thermochemical cycles (6). By analyzing reversible processes, limits can be placed on the best performance that can be achieved for a given cycle. For example, H2 could be produced through chemical reactions powered directly by the heat from a nuclear reactor, such as zinc reacting with water to produce zinc oxide and H2. The zinc is recovered by heat-driven decomposition of zinc oxide. A thermodynamic analysis has shown that the currently proposed thermochemical cycles for producing H2 cannot compete with electrolysis of water through direct use of electricity (6).
Thermodynamic analysis of reversible processes can be coupled with theoretical efficiencies to allow comparison of real processes. Such an analysis was performed for direct H2 use for transportation, and the findings were compared with other strategies for reducing greenhouse emissions and U.S. oil imports (6, 10). This work has brought to light serious concerns about the feasibility of an H2 economy.
However, recent work suggests a path forward for the sustainable production of liquid hydrocarbon fuel for transportation that would make use of H2 produced from carbon-free energy, such as solar or wind (1, 11). These processes add H2 to the syngas (CO and H2) produced from gasification of biomass, a
...would it cost me to buy one of these things?
"During My Service In The United States Congress, I Took The Initiative In Creating The Internet." -Al Gore
Yeah, it's a troll, or even binspam. Trying to reignite the "clean coal" thing. And we don't need to use foodstuffs to make biofuel, not with all that blue-green algae floating around.
No one in the industry I am aware of would say one of those tiny (those montana and skystream models are the exception there, as they are more realistically sized) windchargers would power a household. And further, no one credible who sells or installs realistically sized residential windchargers would recommend it be installed on a household roof. I have a very small windcharger, 300 watts max output in ideal conditions, it is designed to provide a small amount of battery recharging capability for like sailboats or a small weekend cabin or something, and that's it. Same as no one solar panel is going to power your home. This is the duh part, I mean, read the dang specs before you buy and try to keep in mind what your demand would be. There are still a lot of decent windchargers out there that fall between these tiny models and those megawatt sized hugemongous models.
This was sort of a *really* stupid test. Might as well throw a lawnmower engine in your caddy to try and achieve epic mileage, and then see how far you get down the road. It is that dumb to anyone who knows anything about alternative energy.
There are tens of thousands of people who own and use residential windchargers, all over the planet, but they are all designed for the task, they are all large, and mounted on sturdy tall towers. The mentioned two largest ones there should be considered entry level in size for practical household use. Yes, size matters obviously, and this info has been out there for close to a century now as regards wind to electrical power.
Sure, we're not all US, but US households are becoming a de-facto benchmark because they're the biggest consumers of energy on a per-household (or per-capita) basis.
It makes sense that as developing nations, well, develop, their energy consumption increases respectively, and approaches the consumption of your average American household.
If americans lived in Holland, rather than California, Texas, or Florida, then they wouldn't need A/C for 90% of the year.
How many homes in the Mediterranean region (Greece, Italy, etc.) have A/C? How do they build their homes?
One thing I've noticed in a lot of North American construction is that it's basically the same regardless of where in N.A. you are: concrete foundation, cinder block basement, 2x4 framing, fibre glass insulation.
This is more or less the same from California and Arizona, to Oregon, to New England, to Florida. You'd think that different climates would use different construction techniques and materials. The houses in Sweden are generally not built the same as the houses in Greece.
Perhaps, instead of adding things like A/C after the fact to moderate temperature (and humidity), we start with a building design attuned to the climate it will have to deal with.
Hey! Don't generalize. Morons come from all around the world, they aren't exclusive to the US. It's just that our country happens to produce the most.
the real deal is to plug it directly into the supply, don't even include your house in the circuit. all of the power generated will be measured by your supplier, and a credit applied to your bill, dollar for dollar at their price. some research into which solutions have the best specs for the price, and figure your payback point. that's why i'm intrigued by wind power, the fuel is free, only the equipment costs. repairs are more likely than replacement as opposed to current solar arrays that i've seen.
If you don't like >100F weather, why are you living there?
I saw no mention of the EPA in the article.
However, were it not a troll, the "Try again." comment would bother me. Someone may have little to contribute to the thread except for a link to a journal article. Let them post it! It still gives information to a non-negligible subset of the slashdot readership.
It would be more practical to hook up a generator to a bike or rowing machine and use a battery or flywheel to store the energy -- that way you'd at least get some exercise out of it.
There's an easy joke to make about 'mericans sitting right there, but I don't have the heart to reach out and grab it right now. :P
Karma: Excellent, but still won't get you laid.
Yeah, I try to keep up with this stuff, since I live in a location that has an "above average wind energy density" to put it mildly. Just last week I saw a hyped article about a new small turbine, went to their web site, and they're claiming that their device only costs about $5,000 installed and will generate 500kWh/year. I blinked. I re-read. I went to other pages to see if that figure was a typo or consistently used. But nope, that's what they're claiming: for only $5,000 up-front I can generate $50/year worth of electricity. And to think, some of the founders will probably be surprised when the company is out of business in a very few years.
So, obviously, I thought that it was ridiculous (and sad) that a company would offer such a low-producing product at that price. But looking at these test results, $5,000 for 500kWh/year is actually hugely better than most!
I looked up my electric bills since August 08 and added up my total energy use. 7204 kWh over 9 months, for an average of 800 kWh/month and a projected yearly use of 9600 kWh. I live in South Carolina but I haven't lived through a full summer here yet (and won't). The electric company had a variety of tools to display my energy use including a nice set of graphs on their website.
It's great most of the time, but sometimes you need an air conditioner. We can't all live in perfect climates.
There was one windmill that two of them would power a whole house.
Well, yes, at an enormous cost that would put the payback at somewhere around 100 years, give or take.
2 to power an average Dutch home, an American home takes on average 3 times more energy. Important bit in TFA: the 18-meter windmill nearby only cost about 20% more than the combined cost of all the small windmills, yet it produces 20 TIMES the power.
Actually, many state and local ordinances control that. It is now legal in the town I live in (Islip, NY).
You are either (1) misinformed, (2)just plain out wrong, or (3) a troll . Pick #2 and #3 or #1 and #2.
George: What is Holland?
Jerry: What do you mean, 'what is it?' It's a country right next to Belgium.
George: No, that's the Netherlands.
Jerry: Holland *is* the Netherlands.
George: Then who are the Dutch?
You really should check things like article links more carefully if you want to quibble about "news" versus "discussion." The summary link: http://www.lowtechmagazine.com/2009/04/small-windmills-test-results.html, astonishingly is to a "journal." It is the author of the journal article that asserts that "small" windmills "are a swindle." The references to "design" by the OP also appear to derive from an uncited link: http://www.lowtechmagazine.com/2008/09/urban-windmills.html, to another journal article that debunked small windmills as a poor investment, or as the authors of the linked article put it "fundamentally flawed." There is in fact apparently nothing in the summary by the OP that does not appear to derive from a "journal" source, if you consider that important. So, evidently it really IS news, wouldn't you say?
------ The only greater hazard to your liberty than n politicians is n+1 politicians.
Tall buildings and skyscrapers are a boring part of the city scape. Nothing ever moves. They are only pretty with Christmas lights.
I suggest Turning the Burj Dubai building into not only the world's tallest building, but also the world's largest windmill. At that height, one swing should power the whole world for the year!
Dutch province of Zeeland
There is your answer.
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
When did you sell your tulips?
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
So, did you work out where the energy was coming from ?
It comes from the eventual depolarization of the magnets being used.
Very interesting. Nice amount of power at ground level, and the local windspeed didn't look too high either, those magnification vanes look to do the trick quite well. If they get a non flash site I'd be interested to see what they cost.
Yes I do, and that is helped by living in a place where the entire ground floor is sacrificed for cooling and by having very high ceilings and overhanging eaves. The ground floor has no walls, just slats to keep people and animals out but to let the air flow. Having a lot of shade to give cool air underfoot and all the really hot air way overhead keeps things bearable up to nearly 40C by which point the floor is unpleasantly hot. Thin walls means it's not much different to being outside under a big shady tree as far as the temperature goes - just as well it never gets really cold here at night. The modern improved and extreme version of the design is the "love shack", where the living/working area is a very long way off the ground and there are no windows on the sun exposed side.
The opposite approach is the Greek Island one of really thick walls made of pumice (huge amounts of insulation) with the outside painted white to reflect a lot of sunlight. With cool nights and hot days that would probably be a better approach.
That said, at work I have to use a shirtload of air conditioning to keep computers cool and at home have to use the pedestal fan pointed into the open case trick.
My point is with better building design you can cut down on the need for airconditioning but that can mean major changes. Solar thermal airconditioning isn't hard either, but the tricky bit of distribution of the cooled air means that since you need electric fans you might as well do it all by electricity anyway.
Most of these seemed to follow what they said; rotor size directly affects energy output. But the Skystream seemed show about 265% more energy output for only a 20% increase in rotor size over the next best performer. Design would have to account for some of this, yes?
You choose to live somewhere like that.
Xavier Rabourdin for president 2012
Why should we be happy about cheap petroleum derived from coal? Coal is still a fossil fuel, which means that making fuel out of it, then burning the fuel, is just as damaging, greenhouse-wise, as burning the coal itself would be.
Obviously there's a lot to be said for reducing the soot and sulphur pollution, but ecologically speaking I would prefer that countries which are unable to convert directly to carbon-free technologies like electric cars pursue biofuels made from algae. This technology is incredibly impressive in its potential, and unlike current first-generation biofuels, could scale sufficiently to meet world demand in petrol use.
Wow, reading more I see how blatantly WRONG this summary is.
In addition, Zeeland is not in Holland; they're separate provinces. Don't trust anything in the summary!
Even so, the small windmills look bad compared to the large unit that was also mentioned.
Best one in price/performance among the small units: The "Skystream" with 10,742 euro for continuous power output of 240.7 watts. That is 44.63 euros per watt.
Large unnamed unit with 18 m rotor diameter: 190,000 euro for continuous power output of 16,324 watts. That is 11.64 euros per watt.
So the article is right, big is better. Note that they did not diss wind power in general. Only small units with poor performance compared to the price.
C - the footgun of programming languages
I only took one season of Benny Hill German in high school. My apologies to the Dutch.
Plus that's an *average* American house. Presumably, any house that is build planning to take advantage of only wind and perhaps solar energy will be constructed with efficiency in mind.
The results are actually very encouraging. It seems like, if you lived in a windy area, you could have a windmill + solar panels and power a small house *and* an electric car.
(that assumes you have some way of storing energy during windy/sunny periods and releasing it during calm/nighttime).
I don't think he really cares...
-AC
You want to look at price per kwh. According to this overview, average price per kwh in The Netherlands is 0.28 per kwh. The Skystream is the most efficient generator per kwh at 5.09 EUR.
Without discounting to present value or accounting for inflation or other possible future taxes, you need 18 years of flawless operation to break even.
Read what I mean, not what I wrote.
Having grown up in a household whose total electrical needs were powered by a single 3m wind generator, I'm finding this article summary awfully amusing.
But what sort of idiot puts a windmill on a roof? There are so many things wrong with that.
1) A roof is way too low. The optimum height, in terms of tower cost versus power value, for a turbine of scale sufficient to power a household is generally at least a hundred feet, and preferably notably more. Wind roughly follows a so-called "1/7ths power law", so those first hundred or two feet up make a huge difference. After that, it's a case of diminishing returns.
2) A roof is high turbulence. Turbulence is very bad for wind turbines -- robs them of powers and stresses their hardware. You want to be well above sources of turbulence.
3) A roof is generally not nearly strong enough, and would have to be reinforced anyway.
4) They weren't even bothering to test on a roof in their study.
One thing this article left out was the tower. That may seem like a trivial thing to most people here, but it's not in the least. I made a spreadsheet to crunch the numbers when I was looking into wind power. I found that it actually can be approximately breakeven where I live (in Iowa) if you're out in the countryside so that you can build a very tall tower, and you use a guyed tower**, and you can get a good deal on the tower, and you're grid connected so you don't have to deal with power storage, and you're not an idiot when it comes to turbine selection. Yeah, a lot of "Ifs". But regardless, the tower generally makes up 50-75% of your total costs in a properly designed home-scale system (20-25%-ish on a commercial-scale system).
"You see, Government is a system that is based on weapons." -- Timster
Her agenda isn't going to stand up to the wind towers that just started operating 15 miles away that people can just go look at though.
Don't count on it. Never underestimate the persistence of a narrow minded person. And believe it or not, some people are willing to lie to advance their agenda. Like finding some specious way to link infrasound to autism and alzheimers.
Another day, another update to a Google android app.
Yes, and I also choose to run my A/C in the summertime.
Let's see if we can wake some of you sheep up, see: interview of Brian O'Leary.
Larger rotor diameter generators obviously are advantageous. But this study/article seems to not acknowledge an interesting approach that was investigated in Britain: (In areas with sufficient regular wind), houses/buildings whose roof pitch is parallel to the common wind direction (i.e. the roof line is perpendicular to the common wind direction) can exploit their aerodynamic shape to boost the efficient of smaller wind rotors. With an additional "wing" form mounted above a row of smaller wind rotors (like a little roof), combing with the increased local wind speed generated by the roof pitch, the smaller rotors can easily achieve efficiencies of >2x the same size rotors not mounted to take advantage of local aerodynamics. This type of approach is of course generated at the site of usage, so has no transmission losses. Design doesn't matter?
Wow, reading more I see how blatantly WRONG this summary is.
1. You RTFA
2. You assume the summary is right
What's wrong with you?
Yeh, the summary seems to reek of anti-green, or at least anti-wind technology. The assertion that 141 are required assumes that you are using the worst windmills in the US. A clear sign the submitter is not only anti-alternative energy, but also an obnoxious American.
Actually, it reeks of anti-"I'm a trendpoppet with a micro windmill on my roof so I can preach to you about how holy I am by using recycled toilet paper". They seem to me to be just saying "yeah, these small windmills really really suck compared to just having one big windmill powering a bunch of homes".
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
http://www.windside.com/
This will work is in faster and slower winds than your traditional propeller. It's silent and durable. Cheap and easy to install.
Now watch for it: I [predict that the so-called "environmental movement" will scream in horror at this prospect, and we will learn yet again that they are mostly about enforcing eco-puritan poverty on us all
Awww Shit- just nuke 'em all.
BUT- AND I am serious- try 'n conserve energy any way possible- such as less hot water for showers, and recyl... WTF...?
Sorry- my damn altruism almost had me there! Hah!
.
- aqk
F U
With all these propellers spinning, don't they make the earth rotate faster?
I am anarch of all I survey.
Solar hot water heaters are pretty much standard in Australia too, at least near where I live. Most houses will have one, and while you have an electric booster for when its needed, even in winter they do a pretty good job of keeping the water hot. In summer it comes out practically boiling.
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
I suppose if "the average american household" wasn't so energy inefficient (or just plain wasteful) the windmills in question would have seemed far more cost effective.
That's why there is the whole "reduce", "conserve", or "use less" part of the equation, that Americans traditionally don't want to deal with.
you had me at #!
I went to a "Green Expo" last year, and saw one booth with a small windmill, with about a 2 meter diameter 3-blade carbon-fiber blade assembly. The blades were fixed, and there was no overspeed feathering/furling capability. This was $10,000. Using their numbers, payback time was a century.
The going rate for a 2m turbine is about $1000. So I asked the sales rep why their unit was so expensive. He said "this is a status symbol, like a Mercedes". Right.
The tech is fine, just this particular test was sorta lame. I think solar PV works quite well, as do realistic sized windchargers. I own a small windgenny and several solar PV panels myself, along with fuel generators, all for backup.
I lived at another place as a caretaker that was mostly powered with solar PV and it was just spiffy, whenever the local grid went don't, we didn't, And this wasn't a joke little place, it was a three story huge house with full everything normal. The only thing that didn't run off of solar PV was the ancient heat pump and an electric range, everything else though, lights, fridges, freezers, the well pump, many computers, big screen TVs, you name it, all solar powered at around 30 grand price 9 years ago now (and that could have been cheaper, the owner paid for full install and we really could have done most of it).
I maintained the system and it was very easy, and it even worked well during extended periods of heavy clouds, etc, several days worth of power in the battery banks as long as you weren't totally nuts about using it. Heck, I posted on it back then right here on slashdot. There were only a few tricks to using it, the main one was to schedule heavy loads for as close to midday as possible, during times of maximum solar gain. We'd do the washing and water the garden, etc around those times. That was really the only thing "different" I can recall about it, every other use was normal "on demand".
So, I am proly one of your envirowhackos who think it works and should be used more, because I've seen it work.
There's no magic one silver energy bullet, but a nice mix to fit the situation here and there could go a long way to reducing dependence on coal and petroleum. I've been into alternative energy since the late 60s when I helped build a simple but effective solar swimming pool heater. Solar power is the only practical fusion power we have now, and wind in areas that can use it works so good it is a commercial success today. I've also worked extensively in the superinsulation retrofit and construction biz, we have the tech now to drop most household power demands down to one third or even less with NO new technology being needed and using just a saner approach to building, with maybe a 5% premium cost with new construction. That is BY FAR your best alternate energy dollar spent, really nail the insulation in your home and the other issues like doors and windows, etc. to "superinsulation" standards. It is googleable, some on it at wikipedia if you care to go look, it is quite good tech, and I've seenit work really good as well, like I remember one lady called us up and complained after a remodel that her AC wasn't coming on. I said, "Your house is still cool though, right"? along thoise lines.."Well, yes" "It's working ma'am". She was used to every couple hours having the electric sucking beast coming on, when it went past a whole day and it didn't it freaked her out, she just couldn't believe how good it worked, even though she had paid for it and it is what we told her would happen!
I'm a big fan of that as well. The combination of more and better insulation, more efficient appliances and vehicles, plus more points of production of differing energy sources are just all swell ideas in my book.
I don't like being tied so much to the big energy cartels and weird geopolitical events outside my control and their price gouging, and I really don't like them jerks having all that cash and influence because conventional energy causes wars and massive air and water pollution and health issues. I favor (really just speaking for myself, others can think and live different) a more self independent lifestyle model. Living it now, for instance, we are now producing half of our food here right where we live, in season it proly tops 90% or so. And although we have a propane tank and heater, we haven't used a bit of it for two winters now, pure "stored biosolar", firewood.
I love it every time I eliminate a bill, and can
They are pretty but they don't look very efficient.
http://www.freefoto.com/images/1450/02/1450_02_9---Line-of-Windmills--Kinderdijk--Holland_web.jpg
And some of us live in places that get 100F in the summer, then get to well below freezing in the winter. In just the past year, my house has seen 97F (36C) in June to -9F (-23C) to January. February alone had a range of 0F to 64F. One day last week it went from freezing (32F) to 62F in 12 hours.
There's just no way to build a house for these conditions except to insulate it really well. At best you can minimize the days you have to use AC, but in a climate like mine it just gets to be unbearable without it.
dom
Also the test results, if true, the best windmill would power 75% of the electric needs of the building where im living (3 apartments)
Maybe you don't have the energy requirements of an "average American household". Try adding 4 televisions, three large fridges, two air conditioners per apartment and you'll be halfway there.
As an aside I met lots of people using those in Madagascar in places where grid power is spotty at best (like 2 hours/day) and they seemed to do fine for a moderate use (adapted to the local conditions). Their main problem was battery quality.
May contain traces of nut.
Made from the freshest electrons.
It's no matter of output. It's matter of efficiency.
...).
In fluids, there is a thing called "Reynolds number" which compares the convective forces (from where you can extract power in this case) and the viscous forces (the bad guys which lower efficiency). This number is roughly:
rho*V*L/mu,
where:
rho is the fluid density (the air density in this case)
V is the characteristic speed of the motion (the wind speed in this case)
L is the characteristic length of the motion (the windmill radius in this case)
mu is the fluid viscosity (depends on the temperature)
As a result, a windmill twice as bigger, is more efficient than two smaller counterparts.
In aerodynamics/fluid mechanics: size matters! (that is why we tend to construct larger airplanes whenever is possible -they will fly full of people-, larger boats, larger windmills,
I'm not sure it's the most morons in the US, just the most who can be heard and seen by others.
When what we consider poor is a lifestyle better then the rich in some areas, we have a lot more opportunity for the morons to be seen where typically, they would be pushed off to the side.
yep, zeeland is in the netherlands, "holland" technically is only 2 provinces on the west coast.
While it is common usage, it's still dead wrong.
Make a man a fire and he will be warm for a day, set a man on fire and he will be warm for the rest of his life
We should be happy about Coal because it does with two issues that more people will agree on then the Carbon-fossil thing. It's locally mined so it will reduce foreign dependency on oil and it will create jobs inside the US.
On a science note, we can actually make coal from biomass so fusing the two together could lead to a renewable carbon neutral process. So discounting it as of right now, it only closing the doors to the future.
> It would take up to 141 small windmills to power an average American household entirely using wind energy, for a total cost of 780,000 dollars.
This says little about wind turbines but everything about the wasteful lifestyles of the yankee...
... tilting at windmills again!
It would be more practical to hook up a generator to a bike or rowing machine and use a battery or flywheel to store the energy -- that way you'd at least get some exercise out of it.
There's an easy joke to make about 'mericans sitting right there, but I don't have the heart to reach out and grab it right now. :P
"Let's have a moment of silence for all those who are stuck in traffic on their way to the gym to ride the stationary bicycle."
Earl Blumenauer (D-Oregon)
I'm old enough to remember when discussions on Slashdot were well informed.
Maybe you don't have the energy requirements of an "average American household". Try adding 4 televisions, three large fridges, two air conditioners per apartment and you'll be halfway there.
Yeah! And we all drive three SUVs at the same time, to maximize our baby-seal-running-over potential.
However, when I hear that many houses in places like California still use antiquated buliding techniques/materials like single-pane windows I wonder how much of that air conditioning is actually neccessary. Double-pane isolated windows and a layer of mineral wool between the facade and the space inside the house could at least increase the effectiveness of the A/C, making you require less of it, thus saving energy. The best part is that there are no upkeep costs as long as you don't go around breaking your windows.
USE HOT GRITS WITH STATUE OF NATALIE PORTMAN (NAKED AND PETRIFIED)
Sounds like a Queenslander.
My ism, it's full of beliefs.
I dunno, Queensland is pretty hot to me.
My ism, it's full of beliefs.
The cheapest turbine they have is 4300 euros. This is ridiculously high price. In Finland, you get a 2.1m diameter rotor for less than 1000 euros (controller, mast, turbine), and a full kits with batteries, inverter and solar panels for 1400-2500 euros. A 3.2m diameter turbine here costs around 4000 euros and 8m diameter turbine around 20k-30k depending on configuration. These are list consumer prices including taxes. The prices quoted in the Dutch "test" seem to around 4 times what you pay here!
The quoted average wind of 3.8m/s seems inland wind speed. It is quite obvious that there is no point in installing turbines in locations where the average wind speed is low, but they seem to get some power from the larger turbines, though the price level they have kills the payback times.
They correctly point out that taller mast makes a difference, but one point for large industrial turbines is ignored - industrial turbines do need a grid to deliver the energy. For small turbines, the idea is to use the energy where it is produced, avoiding cost of grid. Grid cost in Finland is around half of the the bill, and taxes around 30%. We have grid/transmission cost separately priced so you can select to buy renewable-only energy from grid).
They did figure out, which I assume most people in industry already know, that the diameter is the interesting factor. The power generated is in relative to diameter and square of wind speed and efficiency factor. There are lots of snake oil companies out there claiming bogus production numbers, which is unfortunate as it spoils the reputation of good idea. There can be easily spotted by calculating a wind area covered by the turbine and dividing that by price. As getting efficiency up by few percent tends to be very expensive, it is easier to just make simple blades few percent longer. The cheapest wind turbines sold here have continuous profile blades, and they still perform nicely, even though the center part of the turbine probably does not do much work.
We have 2.7m diameter unit (www.tuulivoimala.com, 500W nominal) at our vacation home we use in summertime. This is very non-optimal location, only northern winds and too much shadow for solar, so we took more diameter and big battery pack to offset non-windy periods. We use the power for lights, computers, 3g WLAN access point for network. Total cost of all electrical installation including lights, wiring, 2kW inverter, 980Ah battery pack, was less than getting grid to the place. Not enough for heating, but we burn wood for that, the plot is large enough to provide us practically unlimited supply of firewood. The power has been plentiful for our use. Electric chainsaw works for chopping the firewood, though we need to avoid continuously sawing more than 1 hour to avoid emptying the battery pack more than third :)
If you do not have a grid connection, the install cost of it will offset quite a big turbine and solar installation, so small turbines are very popular in vacation homes. And for vacation home, the more remote the better. Which means very expensive or impossible grid connectivity. In Scandinavia, solar does not work early spring or late fall, so wind turbine here may be the only option if you need electricity off-summer times. Combining solar and small wind turbine makes a lot of sense as the electrical installation is similar.
The same thing applies to developing countries. It often makes more sense to go directly to renewables than build grid to every small village. In south solar power or hybrid solar-wind is probably more dominant.
They claim that turbine does not even make up the energy used in making it. This is true only if the turbine is located in a low-wind location, or it is faulty design (no diameter!). I agree fully that it does not make sense to install turbines in city areas where buildings mess up wind flows. The location has to be one with good wind conditions.
To
Exactly, but the Americans would never have heard of it just as I've got no idea what the buildings in the Greek Islands are called.
The reported average wind speed seems rather slow, for that area. The average wind speed is normally more like 6 m/s. Here' s a wind speed map of the Netherlands: http://www.gewiekste.nl/wdk.jpg.
assignment != equality != identity
No no no. The correct translation is:
"I vill not buy this record, it is scratched."
I'm an electronic engineer and I could have told you that the relationship between blade length and efficiency is non-linear. We learnt that at uni. People really need to get over their attitudes against the sight of large wind turbines. It is the only efficient way of doing this. Being a brit, large wind farms over here are a more difficult sell as we are quite limited for space, however several projects are being undertaken. In the states, you have the desert which seems a perfect area to locate your wind farms, dependant on wind levels. Get your hands off the oil :p
Then it would probably surprise you to learn that the GERMANS speak GERMAN, and the Dutch speak DUTCH.
Oh yeah, she has lied, brought in experts to lie, and so on. My point is more that now that people can take a 10 minute drive and look at a windmill that will be pretty similar to the ones that she is agitating against (and talk to the folks who are 'living with them'), the lies will have trouble standing up.
Nerd rage is the funniest rage.
http://en.wikipedia.org/wiki/File:A_Dutch_Leopard_2_painted_orange.jpg
There's really nothing left to say.
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I actually read a paper with the article in it, the Dutch Volkskrant carried 2 articles, one as local news and one in the science section.
Both articles state that 3.8 meters per second on average is actually slightly LOWER than usual, not higher as the summary suggests. Since there is an inverse cubic relationship between wind speed and energy yield (i.e. halve the wind speed and only get an eighth in energy), it's not straightforward to say what the results would have been in a windy year.
The articles state that the larger models are sufficiently efficient to make a profit over one or two decades, but that none of the tested models actually break even in terms of overall energy savings, considering the amount of energy required to produce the windmills. Personally, I think that's hard to say, since you would no longer be needing the alternative infrastructure, but that's what the authors stated.
Also, note that this is news from a newspaper, not a scientific publication, so there might be some details missing that can really skew the results.
Doesn't matter in this case though, since the summary can't even get the details that WERE provided right...
No no no. The correct translation is:
"I vill not buy this record, it is scratched."
You certainly mean: "I vill not buy this tobacconists, it is scratched."
Say out loud: I'm an Aspie and I'm somewhat proud, I guess. Uh. Can I write an email in all caps instead? Hm...
I watched a TV discussion about windmills in the German state of Brandenburg the other day. (FYI: Brandenburg is practically devoid of people but full of windmills.)
The interesting thing was that someone spoke about prototypes of hybrid windmills with hydrogen storage, which were installed recently. He didn't elaborate further, but I guess they produce hydrogen through hydrolysis when the wind blows but the current is not being consumed, and convert it into electricity with a fuel cell when the current is needed, but there is no wind.
IMHO these things can be the solution to the principal problem of wind power, namely that it blows when it wants to, not when it is needed. They can probably even be used to provide a decent base load, instead of requiring a base load provided by oil or coal plants.
Say out loud: I'm an Aspie and I'm somewhat proud, I guess. Uh. Can I write an email in all caps instead? Hm...
Actually it doesn't surprise me at all...that's why I apologized to the Dutch. Perhaps I should apologize to the Germans as well. My paternal grandparents were both immigrants from Germany. I actually took three years of German in high school. That was over 20 years ago and although now it is lost to me from disuse it was quite obvious to me that the articles were in Dutch and not in German. A silly cultural joke isn't always a indication of ignorance; sometimes it is really nothing more than a silly joke.
Don't forget something that most people don't consider - attaching a mill to a roof turns the house into a resonating chamber - much like a hollow-body guitar. The vibrations of the mill will reverberate thru the house and magnify - which is one reason why mills are unpopular - they're seen as noisy, even tho when mounted on a tower, they're not all that noisy at all.
"Alternative energy" has as much connection to reality as "gay sex" does. But let's spend a few more decades and hundreds of billions of dollars to prove the obvious to ourselves. Sqreater
E Proelio Veritas.
Not all that noisy at all?
Is that "not noisy at all," or "not all that noisy?"
One implies now where near as noisy as you would expect, the other nearly quiet. If you were aiming for in between its still hard to figure out.
http://www.otherpower.com/ For actual people who've been using windpower in everyday life.
Also developing DIY windpower systems. I tend to trust actual life activities over lab/study simulations and experiments which may overlook details not practical to reality.
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
The test results show clearly that energy return is closely tied to rotor diameter, and that the design of the windmill hardly matters."
Logically we should construct a couple of windmills the several times the size of the CN Tower, in the middle of the Atlantic and Pacific. They'd power the world!
== Jez ==
Do you miss Firefox? Try Pale Moon.
Well, we Americans are a gassy people.
(ducks)
"What in the name of Fats Waller is that?"
"A four-foot prune."
Just put them in France.
You can do it!
Nerd rage is the funniest rage.
(insert obligatory "My hovercraft is full of eels" translation)
At 6000Kwh one 3.3 meter diameter windmill could nearly power a US household. Add to that that the vertical shaft orientation lets you put the generator on the ground without an efficiency sapping 90 degree CV joint, plus it lets you increase capacity by adding another blade-set above the existing two without an increas in diameter (just height and horizontal loading).
So, that design seems to be the most promising to me unless I have gotten something wrong, which I'm sure someone will point out!
Keep passing the open windows...
Instead of wasting all of this time and mental stress trying to be more efficient in using power, why not work on ways to produce an over-abundance of power? (Nuclear power plant for the home?)
We should expand our use of energy - it drives innovation, produces a better way of life.
If pictures of dead or dying kids will not get the anti-vaccine people to change their minds then I doubt simply seeing a windmill will get those who dislike them to change their minds. Most people really hate admitting a mistake.
I don't expect the woman to change her mind, I expect she will have a much harder time influencing others.
Nerd rage is the funniest rage.
There is a windmill that was approved by the City/County and the neighbors. Until one neighbor sued because the windmill was "ugly". Now the people who own it have a whole roof of solar and a windmill that they can't use.
Even if you have all your permits inline, that doesn't mean you can use it-it's unfortunate but it happens.
Search:
Tracy, Ca windmill
The sum total of human history shows you may be mistaken.
On a science note, we can actually make coal from biomass so fusing the two together could lead to a renewable carbon neutral process. So discounting it as of right now, it only closing the doors to the future.
Pointless. Making ethanol out of the biomass is cheaper, carbon neutral, and much more energy efficient than burning coal.
Oh yes, and it's a good thing you pointed that out, or we would have been very disappointed to have our solar-powered electricity fail simultaneously with the heat death of the universe.
If the Dutch lived in California, Texas, or Florida, rather than Holland, then maybe they wouldn't need A/C for 90% of the year there either.
A/C use is partly climate, but also a lot to do with attitude, dress culture, and in how you adjust to your surroundings and what you let your body become accustomed to. Remember that the reason those areas are densely populated is that people migrated there by choice in the years before A/C was available
Lol.. flamebait for saying it's not that there is more, it's that they are communicating more. Nice, I guess someone god mod points that I pisses off recently. I love this place, it reminds me of second grade in times like this.
I agree that it is doable but unlike in Europe the houses here are all wood which seems to make the walls a lot thinner. In fact our estate agent was not happy when she asked what we were looking for and I replied a house made of bricks - they do exist but not in our price range! The result is that the walls are thin, even though insulated, and there is no cavity wall to pack with more insulation.
Additionally the winters here in Edmonton range from -10 to -30 (and sometimes lower) so they are significantly colder. However the summers are quite warm +23-28 and even with the insulation we have the house becomes stiflingly hot to the point where we have thought about air conditioning which would probably negate any savings made in the winter.
There is a big problem with going with a highly insulated home: moisture.
Actually all the walls here are hermetically sealed - something I'm not a fan of because the house becomes stifling in summer. The reason is that with the temperature outside -10 or lower any moisture inside will condense and, as it moves further outside, freeze. The result is a moist layer at some depth into the wall which will happy rot anything there. Even with thin insulation the problem would exist because of the temp difference and the humid beings inside. Air circulation will simply move the condensation somewhere else. The only way to stop it is to seal the wall.