12 Small Windmills Put To the Test In Holland 510
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."
Actually, it would take 6 windmills (Score:5, Informative)
Re:Actually, it would take 6 windmills (Score:5, Informative)
Which is also the biggest by far, 5m in diameter. The trend was very clear, despite the obfuscation with efficiency, cost and integer number of windmills all rolled into one. The bigger they are, the better they work.
Commercial 18m: 190000 / 143000 = 1.3 Euro/kWh
Montana 5m: 18508 / 2691 = 7 Euro/kWh
Skystream 3.7m: 10742 / 2109 = 5 Euro/kWh
Passaat 3.12m: 9239 / 578 = 16 Euro/kWh
And the crappiest were even smaller, though I'm not going to bother to do the math for them. In other words, none of these are worthwhile unless you absolutely can not throw up one big windmill instead of five small.
Re:Actually, it would take 6 windmills (Score:4, Interesting)
I'm just gonna set this [michaelbluejay.com] down and back away while people flame me for endorsing coal/oil/nuclear based electricity.
Re: (Score:3, Insightful)
Re: (Score:3, Insightful)
Re:Actually, it would take 6 windmills (Score:5, Interesting)
Re: (Score:3, Informative)
Commercial 18m
currently, windmills of 2Mw are being installed everywhere. those have 80m diameter, So that 18m one is a very small one.
Re:Actually, it would take 6 windmills (Score:5, Interesting)
Re:EPA would never let you build them (Score:5, Insightful)
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.
Re:EPA would never let you build them (Score:4, Informative)
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
Re:EPA would never let you build them (Score:4, Insightful)
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.
Re: (Score:3, Interesting)
Not to mention the 24 MILLION people living in Texas, notably Dallas and Houston. Dallas is less than one degree north of Cairo, Egypt, and come June-September you wouldn't be at all surprised if one day you saw pyramids here. From June-September the temperature never, ever, ever drops below 84 degrees, even at night. Meaning that the houses get heat soaked and really you're just cooling the air inside the house - the walls and structure never get below 90 degrees. People set their AC at 78 degrees but even
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And yet, the DFW area didn't have its population boom until the advent of AC... Not to mention any house built since 1960 (that would be 95%, possibly higher) were designed for closed window ventilation via AC. Not having air condtitioning working is a MAJOR emergency here come august, a house with closed windows and no ac can easily reach 95 degrees in August. Plus it takes several days to pump most of the heat out of the internal walls, furniture appliances etc. In other words its fucking miserable. Its p
Re:Actually, it would take 6 windmills (Score:4, Interesting)
Not to mention both dallas and houston sit on top of 50 ft of clay the consistency of partially frozen jello pudding.
I am not a brick-maker, but this looks like an excellent resource to bake bricks. And it is, as you write, incredibly abundant. So it should be easy (and cheap) to build thick brick walls. My house has 24 cm (10 in) brick walls which provide a decent heat insulation. Not by today's German standards for new houses, of course, but well enough.
While I agree... (Score:5, Interesting)
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.
Re:While I agree... (Score:5, Insightful)
Or nuclear. It's proven, it's working today, and there's phenomenal amounts of energy.
When did America become so retarded?
Re: (Score:3, Interesting)
Nuclear does make a big target - but any centralized power system will. Not sure what the effect of a 20k non-nuclear bunker buster would be.
Wow, you Americans sure are paranoid... (if you are not American, I'll be surprised)
The nuclear energy debate has come up on my country, and the #1 issues are the fear of an accident, and how to manage waste. No-one even THOUGHT about the possibility of a terrorist attack. Makes me glad to live in Uruguay.
Re:While I agree... (Score:5, Insightful)
Hypocrite.
The second law of thermodynamics has nothing to do with a discussion on future energy sources for the Earth. You could have just as easily mentioned that the sun is eventually going to kill off all life on the planet. Neither fact is relevant.
Honestly, if you hadn't quoted my post, I'd question whether you were actually replying to it, and not some other post. This is not a physics problem, it's a question of resources. If you have some evidence that our readily available nuclear fuel will not be exhausted in a relatively short (i.e. centuries) amount of time, please post it here.
In other words, prove me wrong before acting like a supercilious douchebag.
Re:While I agree... (Score:4, Insightful)
Sailors all over the world use small wind generators to charge their batteries while at anchor.
That doesn't tell me anything if I don't know the size of the battery or the rate of charge.
Sunforce Air X Marine Wind Turbine [amazon.com] 12 Volts. 400 Watts at 28 mph. 46" Blades. $750.
It strikes me that anchoring in 28 mph winds would keep you usefully occupied managing other problems.
Re: (Score:3, Interesting)
Sunforce Air X Marine Wind Turbine 12 Volts. 400 Watts at 28 mph. 46" Blades. $750.
It strikes me that anchoring in 28 mph winds would keep you usefully occupied managing other problems.
Indeed. I've overnighted in a 44' sailboat while anchored in 40 knot winds more times than I can count. Sometimes you just don't have a choice. Fun times. I call it vacation :-)
The turbines work well and of course provide power in lower winds. It all adds up when charging batteries. Though they tend to be noisy, so we u
Re: (Score:3, Informative)
Re:While I agree... (Score:4, Interesting)
You know what's really funny? Sailors all over the world use small wind generators to charge their batteries while at anchor.
Yacht marinas tend to be built in windy places, so there is plenty to keep the blades going round. Also the power requirements of a small boat are very modest, much less than that of a typical house - high energy things (like cooking) tend to use gas or something.
If you think about it, the energy that a windmill can extract is going to be proportional to the amount of air that it can interact with - this will be roughly proportional to the sweep area of the blades or proportional to the square of the blade length. You will find that the power generated is roughly length^2 - do the math on the numbers that they quote.
Re: (Score:3, Interesting)
For a couple of years, we ran a project [pfaf.org] completely off the grid, no electric, no gas, no water. Our power rig was a small wind tu
Re:While I agree... (Score:5, Interesting)
Yes- I believe in a world where people strip houses of wiring and pirates attack ships, that the large commercial windmills that contain very large copper cores
Those would have to be some brave freaking looters [pennnet.com] who really know what the heck they're doing [treehugger.com] if they don't want to, you know, die.
Design hardly matters...? (Score:5, Interesting)
Apparently it does matter, and these were obviously very poorly designed if three of them straight up broke.
Re:Design hardly matters...? (Score:5, Informative)
Clearly, designs made a huge difference in output
How the hell did this bit of poor reading comprehension get a 5 informative ranking?
Look at the size of the blades and the power produced. They are VERY proportional. Design didn't make much difference at all. What counts is the total surface area of wind you are taking advantage of. i.e. blade size.
The smallest unit had about 1/25 of the blade area coverage as the largest one, and produced fairly close to 1/25 of it's power.
Take home messages:
1) Design doesn't matter.
2) You are going to get ballpark 10 watts/square meter of wind in a windy area (avg 3.8 meters/sec wind)
4) A smaller number of large windmills are more cost effective to buy then a bunch of tiny windmills with the same surface area.
Re:Design hardly matters...? (Score:4, Funny)
The folks that got screwed where the buggy whip makers. There just aren't many ways to modify a buggy whip into something that meets a need in another market.
Ummm, try the booming erotic services market.
Re:Design hardly matters...? (Score:4, Interesting)
Guess where most of the riding crops they manufacture go? Not to riding schools, I can tell you.
Slow (Score:4, Informative)
Re:Slow (Score:5, Funny)
Yeah. You'd have ALL of them break.
Re:Slow (Score:5, Interesting)
3.8 meters/second average is not a windy area
No kidding! This is a "study of wind power in an area that anyone who knows anything about wind power knows is unsuitable for wind power." Duh.
The Government of Ontario has an excellent resource on available wind in the province:
http://www.lio.ontario.ca/imf-ows/imf.jsp?site=windpower_en [ontario.ca]
The legend doesn't even go down to 3.8 m/s!
On my block, which is downtown in a lake-shore city, at 100 magl (metres above ground level, an acronym that does not appear to be defined anywhere on this otherwise excellent site) the average wind speed is 6 m/s, which is in the acceptable range. Because available power goes as the cube of wind velocity 6 m/s is nearly a four times increase in power over 3.8 m/s!
Small windmills are not for everyone, but this study is simply bogus if they're reporting the wind velocity correctly.
wrong wind speed (Score:3, Informative)
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 [gewiekste.nl].
Re: (Score:3, Funny)
Don't worry, once word gets out that Ontario has vast reserves of untapped wind power, we'll be invading them within the month.
Re:Slow (Score:4, Funny)
Careful there, wouldn't want to get the White House burned down again.
Re: (Score:3, Informative)
Your argument is actually way off, 3.8 m/s is rather windy...
Err... no. My argument is not that "3.8 m/s is not very windy" (although it's not). My argument is "3.8 m/s is well known to be far below the acceptable level of wind required for wind power."
With regard to the first point, as others have pointed out here, 3.8 m/s is Beaufort force 3, which is technically known as a "gentle breeze", and spans the range of 7 to 10 knots. While you can have a nice day on the water under those conditions, it is no
But the electricity (Score:5, Funny)
Re:But the electricity (Score:5, Informative)
Dutch: 6310
USA: 13,388
Re:But the electricity (Score:4, Interesting)
I run about 30,000 KWH per year in my house. I was pretty distressed by this amount compared with both the Dutch and US averages, until I factored in:
1) All electric -- no gas
2) Climate where Heating Degree Days outnumber Cooling Degree Days 3 to 1
3) This house, even though it's all electric, consumes only half the electricity of my PREVIOUS house, which was not all electric
4) 6 people live here
5) I work at home, so the house is always occupied
6) I run a small datacenter at home, so not only does all the equipment have to be powered, it has a separate cooling unit.
Given that, I don't feel AS bad. However, it's still a lot of electricity. Yes, I replaced all incandescents with fluorescent about 10 years ago, so that helps.
Re:But the electricity (Score:4, Informative)
www.allianceforwaterefficiency.org/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=2538
Source being the IEA. The figures are based on 1998 data.
Re:But the electricity (Score:5, Interesting)
Dutch use 339L/person/year (2000)
http://earthtrends.wri.org/pdf_library/country_profiles/ene_cou_528.pdf
US use 1672L/person/year (2002) http://tonto.eia.doe.gov/dnav/pet/pet_cons_prim_dcu_nus_a.htm [doe.gov]
Around 5x as much gas used yay.
Re:But the electricity (Score:4, Interesting)
I never understood why we don't use rowhouses.
Who is "we"? In the US, I'm having trouble thinking of cities without extensive use of row homes (or as they are now affectionately called - townhomes).
Personally, I hated living in them. Loud neighbors and an inability to be loud yourself, usually no garage and general parking woes, skimpy yard space, darker since you can't have windows on the sides, and the fact that a single fire can wipe out multiple units quickly. As for the heating savings... my cheap, poor next door neighbors never turned on their heat, so we (along with our neighbor) ended up paying for their heat as well as our own. And none of the owners could agree on a roofing/siding/paint scheme, so the whole block looked like it was decorated by an insane person.
Why don't they install tidal turbines instead (Score:5, Funny)
Why don't the Dutch install tidal turbines in their fields instead, and wait for their country to flood.
Oh I kid, I kid
A little sad. (Score:5, Insightful)
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.
Re: (Score:3, Informative)
You mean this [newegg.com]?
What I would like is "smart electronics" so I can push a single button on my way out and be sure I am not wasting electricity, without shutting off my fridge, alarm clock, and PVR. Maybe somebody can point me to that?
HMmm. I am curious (Score:4, Insightful)
Re: (Score:3, Funny)
Yes, but they're both square-ish and have roofs, stairs for multiple floors, ceilings and doors usually high enough so you don't have to duck, places to cook and to poop and to sleep, furniture...man, I had no idea I'd find so much alike when I started this list!
Anyway, all those things clearly outnumber your little difference that you hardly even notice when inside them. Let's not make a mountain out of a molehill, eh?
Re:A little sad. (Score:5, Insightful)
If americans lived in Holland, rather than California, Texas, or Florida, then they wouldn't need A/C for 90% of the year.
Re:A little sad. (Score:4, Insightful)
get a window fan
Great. You know what a window fan does when it's a 115 degrees? It acts as a convection oven.
and a attic ventilator
Helps a litte bit. A little bit.
plant some shade trees.
Yeah, and in 20 years when the trees reach maturity, that might be useful.
Re:A little sad. (Score:4, Insightful)
Re:A little sad. (Score:4, Insightful)
Phoenix or Las Vegas average temperature in the summer months is around 40C (104F). The hottest places in southern Europe are nowhere near that.
Call me stupid, but perhaps it's a little short-sighted to build cities where humans can't naturally survive. Why do you think Europe has developed so fast over the last few millenia - perhaps because they didn't need to struggle against the elements to grow crops and survive.
Re:A little sad. (Score:4, Insightful)
I wonder if you logically extend this attitude to starving Africans?
Re: (Score:3, Insightful)
I wonder if you logically extend this attitude to starving Africans?
I would. Not as in I'd let them starve to death, but as an opposite "teach a man to fish":
Find a way to migrate them/end their dependence, and you only need to sustain that.
Find a way to sustain the unsustainable, and you must continue to sustain them forever.
Re:A little sad. (Score:5, Informative)
bigger houses in USA = more air to heat/cool
I think there are a lot more gas ranges/water heaters in Europe
I think front load washing machines are much more common in Europe
Let's not forget the stereotypical smelly Frenchman, it is perfectly possible to have first-world societies where everyone doesn't shower each and every day.
Just a comment but from what I see on the TV renovation shows, every window in California is single-pane and insulation is a liberal myth. In Canada you'd freeze to death, in Cali apparently you just crank the AC a little higher and wonder why the power bill is so high.
Some thoughts (Score:4, Informative)
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.
Re:Some thoughts (Score:4, Informative)
No. The 72 TW figure represents only "global wind power generated at locations with mean annual wind speeds 6.9 m/s at 80 m [altitude]". [stanford.edu]
No. You're an order of magnitude off. Global consumption of electric power is about 1.6-1.8TW (same source as above).
According to the researchers behind the 72TW figure, if we could catch 20% of the wind power at the good locations, "it could satisfy 100% of the world's energy demand for all purposes (6995-10177 Mtoe) and over seven times the world's electricity needs".
The idea that you'd spread such FUD about wind power is embarrassing.
Re:Some thoughts (Score:4, Insightful)
Re:Some thoughts (Score:5, Interesting)
You have to remember that once a nuclear power plant is operational it is very hard to make it more efficient than it's design intends. In some cases attempting it has serious trade-off's. i.e. Running the fuel longer produces more radioactive spent fuel whilst using nano-technology to increase the heat carrying capacity of the primary coolant loop makes new (as yet unidentified) isotopes in the cooling water further complicating disposal.
Comparing Nuclear to Wind: Nuclear converts heat to mechanical motion to electricity where-as wind converts mechanical motion to electricity. As discussed in the other post, wind also has a shorter technology development time between generations than nuclear. Implementation of the design improvements takes place at build time for a new nuclear plant, compared to at service time for an operational wind facility of similar capacity. Further, improvements to a wind generation facility can occur without taking the entire installation off-line.
So yes, nuclear reactors will get more efficient, but so will wind. The difference is that the implementation of the design improvements for a wind facility can be implemented while a wind facility is still operational as opposed to a new build for a nuclear plant.
We sorta have that tech. The main issue is (and most people are thinking of an IFR [wikipedia.org] refering to this tech) is the reactivity of the sodium coolant increases the build costs and accident sequence precursors are not known, subsequently the lethality of an accident increases as the reactor ages. Furthermore the Pyroprocessing stage to produce (and recycle) the fuel for it doesn't exist.
IFR is a good design though. If the coolant issues could be solved (like maybe using lead for a coolant) we would be one step closer. The remaining issues would be to have materials technology available so that the lifespan of the reactor could be made to match the waste (fissile ash) decay rate.
The issue here is that the amount of fissionable Uranium is a small fraction of the yield, that is much more U238 vs U235. Most of the easily mined 'soft-ore' uranium is gone. As most of our reactor technology is once-through we find we are in the same situation for uranium as we are for oil. If we increase our consumption, the day just comes sooner.
Hopefully some fusion reactors!!
It's important to spend time examining the supporting technology and infrastructure that is part of the ENTIRE nuclear process, including the political machinations that got us here. The toxicity of the mining process, heavily greenhouse gas producing enrichment process, reactors designed for 40 years only usable for roughly 3/4 of that time and no long term spent fuel containment plan are all issues that have to be resolved for any serious expansion of the nuclear industry to occur.
The lions share of energy research funding, funding that could be used to DEVELOP alternatives, is currently spent on Nuclear power. Even doubling alternative energy research budgets would only take 1/7th of the current nuclear research budget. We could quadruple alternative energy funding and still have plenty of funding to resear
Re:Some thoughts (Score:4, Informative)
With uranium mining you have to process a lot rock to get a little uranium, that is, it takes a lot of *energy* to get the ore in the first place. To put it in perspective extraction takes 2.4 gigajoules per ton for soft ores and 5.5 gigajoules per ton for hard hard ores. To get a kilogram of uranium you have to process 500 tons of hard ore because there is almost no soft ore left. These estimates assume an extremely optimistic extraction efficiency (approaching %50) and assumes you have a high grade ore. Even then you still have to factor the energetic remediation of the mine tailing. If we are to compare nuclear to wind, these are factors that have to be considered when taking about Uranium mining.
If you are going to have a huge energy expenditure just *extracting* the fuel from the ocean, why not just extract the thermal energy from the ocean itself?
Today no-one can make any claims or any comparison between the energy efficiency of those two processes (or if there is an energy return) because both are still theory and not a measurable industrial activities. Sure it might be possible to extract wave energy to extract the uranium from the vast volumes of water you would have to process but you still don't know if it will produce a net energy deficit. Eventually you end up in the position where you could convert the wave motion (or use the extraction process energy) directly for consumption.
Do the math (Score:5, Informative)
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.
And they needed a study for that? (Score:5, Informative)
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).
Re: (Score:3, Informative)
Trust me, the air being forced downwards is the only thing keeping a helicopter (or any aircraft) in the air. Or rather, don't just trust me, trust NASA [nasa.gov] (you can even check their working [nasa.gov]).
I would have thought theory to be flawlesss! (Score:3, Funny)
For a change could everyone read the article (Score:3, Informative)
PV is more cost effective than small wind turbines (Score:3, Informative)
It's in the Netherlands (Score:5, Informative)
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.
Re:It's in the Netherlands (Score:5, Informative)
Also, because people often ask the question of people from New Zealand; yes there is an 'Old Zealand', and this is it.
Re: (Score:3, Insightful)
Then who are the Dutch?
(Seinfeld reference)
VAWTs anyone? (Score:3, Informative)
http://www.youtube.com/watch?v=RRXRUFrxKAQ&feature=related [youtube.com]
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
Well duh (Score:3, Insightful)
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.
some of the small ones are REALLY pathetic... (Score:3, Insightful)
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!
Burj Dubai (Score:4, Insightful)
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!
On a side note (geography) (Score:4, Interesting)
Dutch province of Zeeland
There is your answer.
Finding this amusing (Score:5, Informative)
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.
Re:Finding this amusing (Score:5, Informative)
Sure, if you'll make an effort to restrain your incredulity and be a little more polite.
Propane stove and fridge. 1500 kg lead-acid battery bank. About 15 12v incandescent bulbs ranging from 40w to 100w. Computer on an antique and inefficient square-wave inverter, small b&w TV, two stereos, and occasional power-tool usage. The only hard part is the fridge. Propane fridges really suck, or they did in the 70s.
Apart from that, it's pretty easy if you're willing to live small. Not everyone wants to live like a USian with a strong urge to max out their credit cards on electronics and appliances.
Design? (Score:3, Interesting)
All these propellers (Score:3, Funny)
With all these propellers spinning, don't they make the earth rotate faster?
Little, overpriced windmills (Score:3, Interesting)
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. [windenergy.com] So I asked the sales rep why their unit was so expensive. He said "this is a status symbol, like a Mercedes". Right.
Re:Obvious? (Score:5, Informative)
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.
Re:Obvious? (Score:5, Funny)
Re:Obvious? (Score:4, Insightful)
Misschien kan de man niet Nederlands heel goed spreken of lezen?
Re:Obvious? (Score:5, Funny)
Re:Obvious? (Score:4, Informative)
And it had 5 meter blades, which are way to big for the average rooftop.
Re: (Score:3, Informative)
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).
Re:Obvious? (Score:5, Informative)
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).
Re:Obvious? (Score:4, Funny)
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.
Re: (Score:3, Informative)
Re: (Score:3, Funny)
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?
Re: (Score:3, Insightful)
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".
Re:De-facto benchmark (Score:5, Informative)
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.
Re:De-facto benchmark (Score:5, Funny)
Re:De-facto benchmark (Score:5, Interesting)
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.
Re:Obvious? (Score:5, Informative)
windspeed cubed and radius squared
not to mention the effect of turbulance on o/p
Re:Obvious? (Score:4, Interesting)
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.
Re: (Score:3, Insightful)
[...]and only windy areas will benefit from them.
Well I'm glad we finally cleared that up.
New here? (Score:5, Insightful)
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.
Re:Original research? (Score:5, Insightful)
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.
The "English summary link" might be informative (Score:4, Funny)
Re: (Score:3, Insightful)
"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 tes
Re: (Score:3, Informative)
IIRC, power output increase as the cube of windspeed and the square of surface area. Might have those mixed up. But in either case, no, power output does not scale linearly.
-b
Re: (Score:3, Insightful)