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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.
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.
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.
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
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
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.
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.
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.
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?
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
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.
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.
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!
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.
Actually they are not. In Canada we have a bigger household energy consumption than the US but this is due to heating. When it the winter lasts 6 months and temperatures drop to -40C heating tends to use a lot of energy no matter how efficient your home's insultation is.
Dutch province of Zeeland
There is your answer.
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
I only took one season of Benny Hill German in high school. My apologies to the Dutch.
I thought all your hippy orgies in your communes would keep you warm you socailists.
An Education is the Font of All Liberty
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
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?
No it doesn't have to use a lot of energy. Here in Finland we are beginning to build so called zero-energy houses, which use a very little energy for heating. The insulation is VERY thick, I think it's about 50cm atleast in the walls and more on the roof. My friends house (we live on the southern coast of Finland, winters usually range from 0 to -20 degrees celsius, but more is not totally uncommon), has 60 cm on the roof and has a ridiculously inexpensive electricity bill (both heating and lights etc.)of about 150 euros / month (1 kwh = roughly 10 cents (euro cents)) The house is about 300 square meters total and has three stories.
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.