Wind Power

Factual Questions
1

On a recent cross-country tour of Germany I noticed propeller-type blades on top of structures placed in fields near almost every city. My friend explained that the slightest breeze would set them turning (he also gave some facts about how much electricity they can generate, but I have since forgotten them, due to too much Pils). Why isn’t this means of harnessing the wind being explored here in the US? I should also explain that my friend told me that these “windmills” are considered “eyesores” by many in Germany who feel they detract from the beauty of the landscape.

Q

2

Also they are noisy if you are close to them. Near Mt. Snow VT there is a sizable wind farm. Also there is a new very high power one along the Bering Straight AK - due to very strong winds and not that many more in between. Windpower is considered more expensive then burning oil. In europe, fuel prices are higher then here (I not saying that fuel prices are underpriced here), so my WAG is that windpower is therefore cheaper with the higher fuel prices.

3

I am pleased to report that wind power is being taken seriously in my part of the world. the South Australian government has recently approved funding of about $120 million to establish wind powered generators in two coastal areas. one of those areas is about 30km south of where I live. These will supplement the existing supply to my community by about 5%, which will be useful in times of extreme load (like right now, when the temperature creeps toward 40 degrees celsius).

4

Windpower does have its problems - the obvious one being that you need some sort of backup for quiet days. And, as has been pointed out, wind turbines are noisy and not exactly pretty.

Some European gvts. are giving tax breaks to wind power investors and there are rules in place making it mandatory for the conventional power companies to buy excess power from the wind turbines. This is partly motivated by environmental concerns, partly by economics - lots of European states have to import oil, coal or both.

Back home in Denmark, the current trend is building the turbines off-shore - this makes for less of a visual impact and prevents noise complaints. And while Denmark is poor in natural ressources, we do have wind. A lot of it. (If they could find a way of making power from rain, we’d really be getting somewhere…)

A link to product specifications for some Danish wind turbines, which are supposed to be quite modern:

http://www.vestas.dk/indexwelcome_uk_prod.html

  • these provide from 660 kW to 2 MW, dependent on wind speed - they start generating power in earnest at wind speeds at about 10 m/sec and level out at about 15m/sec.

I’m sure our resident Power Goddess could provide some input on wind power and its place in power supply - are you there, Una ?

S. Norman

5

“Why isn’t this means of harnessing the wind being explored here in the US?”

They are exploring wind power in California. There 5000 turbines at Tehachapi Pass that produce 1,300,000,000 kWh per year, 6000 wind turbines at Altmaont Pass that generate 1,000,000,000 kWh per year, and 3500 wind turbines at San Gorgonio Pass. (From Wind Farms of the World at http://keynes.fb12.tu-berlin.de/luftraum/konst/windfarm.htm))

If you don’t have the pleasure of an ugly, noisy, raptor-killing, wind turbine in your neighborhood it could because you don’t have enough wind or because you have too many intolerant neighbors.

6

I had to drive out to Yucca Valley yesterday (still looking for that Willys CJ2A!) and noticed quite a number of wind turbines out toward Palm Springs. As mentioned, Tehachapi has a large wind farm as well. (Bigger than the one I saw yesterday.)

California has vast deserts with hilly or mountainous terrain. The winds are very reliable. Tehachapi in particular is a good area. The Tehachapi Mountains run roughly east-west and are situated toward the very southern end of the foothills of the Sierra Nevada. This “V” shape makes for a very large natural venturi. Mojave, CA sometimes gets winds in excess of 100mph blowing out of the Tehachapi Pass. California has an abundance of wind that blows through inexpensive real estate in relatively unpopulated areas. There is or was also an experimental solar plant between Barstow and Dagget that takes or took advantage of the desert sun.

I don’t know what the raptor population is in So. Cal., but I do see a lot of them. There are raptors nesting in the skyscrapers of downtown L.A. I see raptors frequently when I fly a helicopter in the local hills. True, they can be injured killed when they try to share airspace with blades that come around every second or so; but they’re smart birds that make their living figuring angles and trajectories. I think they can adapt or have adapted to windmills.

Are wind turbines noisy? Yes. But as I mentioned, they are generally built in unpopulated areas.

Are they ugly? Not to me. I look at them and think about how much better they are than oil- or gas-burning electric plants that spew hydrocarbons into the atmosphere. I think they look rather cool and “science-fictional”.

Backups for quiet days? I lived in the desert for 11 years and quiet days were very few. In L.A. people will talk about wind blowing 10 knots and I’ll say, “What wind?” The electrical system is not a plant providing power for a community. It’s a “grid” in which shortfalls from one plant can be made up for by a surplus at another. So one non-windy day won’t have that much of an impact.

[Great Debate]
By the way: The “power crisis” in California isn’t really a power crisis. It’s all about money. When the state deregulated the power industry, out-of-state suppliers (CA imports about 20% of its power) hiked prices. So now California Edison and Pacific Gas & Electric are hemorrhaging cash. They say they can’t afford to supply power at prices close to the regulated price. (Fortunately I’m on L.A.'s Department of Water & Power, which did not join deregulation. So I’m immune from the “rolling blackouts” and outrageous price hikes.) Not that I blame other states. California should have planned for capitalism. New generators should have been built. Ah, what the hell. I hope to be out of this bloody state in a couple of months.
[/Great Debate]

(*Note: I don’t hang out at GD, so I don’t know if the above has been addressed.)

Back to the OP: Some places have a huge quantity of coal, so they generate power with coal. Some have natural gas, so they use gas. Southern California has wind, so we use it to supplement the polluting, non-renewable resource using plants. As Yeah said, you may just live in an area that does not have constant winds.

7

They are starting to put more up even here in upstate NY. Five or six new ones recently went up on a hill overlooking Madsion NY. The process took several years to go through all the environmental studies and local government approval. Prior to that the company took several years trying to find a good site with lots of wind and a close proximity to a power substation and high power line. I think time is the main reason why you don’t see more of it around at this point in time. It is nice to see that companies are willing to put money into wind power. It is also good to see the locals willing to have this type of power generation in their backyard. They could have just as easily shot the idea down in the planning stages.

8

Windpower is not just “considered” more expensive than other energy sources here (and I will not compare with oil), it is more expensive. And it is still more expensive in Europe, just the difference between it and conventional sources is quite a bit less. Thus, it’s environment-friendly aspect is able to close the gap. This of course ignores all the other issues of wind power (availability, storage, the “condor cuisinart” phenomenon…)

9

People, I’ve said it many times before

Stop referring to oil as an electric generation power source!!!

Let’s start with US data, from the Energy Information Administration

And let’s look at some world numbers too.

From the 1998 International Energy Outlook paper by the EIA (public domain):

From Table 26 “World Energy Consumption for Electricity Generation by Region and Fuel (1995 actuals, and 2000 and 2005 projections shown)”


In Quadrillion Btu's       1995        2000        2005

Total World:              139.4       158.7       178.9
Oil:                       13.1        14.3        15.8
Natural Gas:               22.2        28.1        35.2
Coal:                      50.7        57.9        64.3
Nuclear:                   23.3        24.7        25.0
Renewables:                30.1        33.8        38.6

So let’s break this down by percentages:


Percent of Electric Power  1995        2000        2005

Total World:              100.0       100.0       100.0
Oil:                        9.4         9.0         8.8
Natural Gas:               15.9        17.7        19.7
Coal:                      36.4        36.5        35.9
Nuclear:                   16.7        15.6        14.0
Renewables:                21.6        21.2        21.6

Thus, we see we should really stop using the term “oil” when summarizing fossil energy use in the world for electricity generation. Refer to “coal and natural gas” instead. Thank you.

10

I don’t think that the National Audubon Society shares your belief. I heard a speach from a representative of theirs last year where the speaker called for the “immediate cessation of all wind power generation in California” until some method of deterring condors from flying into the blades could be developed.

For that matter, I think coal plants look really cool. See my post above re: oil.

Yes, it will as a matter of fact. It’s a grid which also suffers from enormous transmission losses too. All it takes if a nice, big static weather system over California and Arizona for a couple days, and see how little power is available from wind.

No, it is largely about money, but it’s also about power availability as well.

And with pipelines and trains, gas and coal can be very easily shipped to California as well. It has nothing to do at all with California’s local coal or gas supply. Of course, if California residents file multi-billion dollar nuisance suits over new pipeline and rail construction, well…

Overall, I agree with you. Wind can be a good supplement, but it is far too expensive right now in the US, relative to other fuel sources. Of course, if one applies the right penalty to CO[sub]2[/sub] emissions, then maybe it can be much closer to equalling out…

11

At this point, wind seems to be a pretty cheap alternative energy source. As of 1995 SC Edison was paying 11.5 cents per kWH for electricity from wind sources. Don’t know how the price has fluctuated in 6 years, but Enron and other generators were charging Edison 50-60 cents/kWH late last month for natural gas-generated electricity (this source has traditionally cost ~3 c/kWH – gas prices are high right now, but not an order of magnitude higher).

CA has three large wind farms, in Banning pass near Palm Springs, in Tehachapi pass north of L.A., and in Altamont pass near Livermore. These generate ~1600 MW, the equivalent of a medium-sized fossil fuel plant.

Advantages: fuel is free, power increases as the cube of wind velocity, maintenance is inexpensive, you don’t need to be near a source of water (for cooling and steam generation), and wind through passes tends to increase in early evenings (when use of electricity is high).

Disadvantages include: like hydropower, ideal locations are limited (though unlike hydropower, we’re not even close to having occupied all of the good sites – total wind energy blowing through Rocky Mountain passes exceeds the electricity use of the U.S. by an order of magnitude); wind can’t be turned up when we need it, though it tends to be consistent through mountain passes; windmills can be noisy and generate EM interference (these are local environmental effects though, as opposed to gas emissions); and they present a hazard to birds, though water intake pipes kill quite a few more fish.

12

Several of you said wind turbines were noisy. They’re not. My subjective experience (I don’t have numbers to hand) is that you can hear the turbines spinning within a certain range of wind speeds when you are standing in the wind farm among the turbines. The sound you hear is a kind of hum resulting from disturbances in the air off the trailing edge of the blade. It has to compete with the sound of the wind in the ground vegetation, and can’t be heard at all 50 metres away.

The issues of cost and requirement for backup capacity have been adequately dealt with.

13

I certainly support alternative fuels, when appropriate, but let me just add this tidbit about wind power…

M.M. El-Wakil. Powerplant Technology. McGraw Hill. 1984.

That’s the ideal (maximum) theoretical efficiency of wind turbine technology. YMMV

14

So what? The wind is free, so coming up with an “efficiency” figure can only lead to misleading comparisons. If you really wanted to take all the energy out of the wind (why?) you could set up a series of turbines of increasing rotor diameter and decreasing return. But if you just want to generate more electricity, put up a bigger turbine.

Check out the “efficiency” of nuclear power sometime!

15

hibernicus writes:

Incorrect. The wind may be free, but the wind turbine is not. After all, the water flowing through hydroelectric turbines is also free, but I don’t hear anyone claiming that that must lead to zero financial or enviromental costs, or that we can just build a bigger dam to generate more electricity (although I will side with jrepka here; we’ve used a lot more of the good hydro sites than of the good wind sites).

You need to look at (among other things) the cost of building a new installation. If it costs USD 100/W of generating capacity to construct a wind turbine, who cares if the wind is free? For that cost, we could build an oil-fired power plant and fuel it from the interest on the money that we didn’t spend to build a wind turbine.

(To avoid the wrath of Anthracite, I will point out that building an oil-fired power plant is neither done nor a good idea.)

16

Around here, it costs around USD 1/W. You’ll understand if I take this comment as evidence that you don’t know much about wind power.

My point about efficiency stands. Betz’s Law is a fascinating result, but it is not relevant, any more than the Carnot efficiency limits for oil-fired power stations are relevant. What matters as you correctly point out is the capital and operating costs associated with your kWh of electricity, not energy conversion efficiency.

So you can’t convert more than 59% of the wind’s energy? No problem, build a bigger turbine and catch more wind.

17

You’ll note that I said “if”, rather than asserting that that was the cost. You’ll understand if take this comment as evidence that you don’t much about English.

USD 1/W appears to be the lower limit for currently installed wind power. Big Spring cost about USD1.17/W; the Northern Alternative Energy projects averaged about UD1.38/W; Foote Creek cost about USD 1.45/W.

That would assume that the wind is infinite in availability. The EIA, however, estimates only 68.2 GW of capacity is available now or in the very near future, with another 168.3 GW becoming available with foreseeable technical advances and cost increases in other generation methods to 2020.

18

Well, 2 comments:

  1. 60% is pretty darn good, compared to solar, coal, natural gas…note I did not say “oil”.

  2. Is that really the maximum theoretical efficiency? No matter what design or size or limiting returns? That was not my understanding, and I have to agree with hibernicus here.

  3. Sorry, hibernicus, but every time I see your name I think “Frostilicus”. Simpson’s reference, I do apologize. :slight_smile:

19

Leaving the merits of our respective arguments aside for the moment, I wholeheartedly apologise for that remark, and would like to retract it. I don’t feel that rudeness of this kind contributes anything to the discussion.

Now, at risk of flogging the same point to death, I’ll just point out that electricity from a 40% efficient coal plant is a lot cheaper than electricity from a 55% efficient gas plant right now. So efficiency comparisons are potentially misleading, all the more so when the energy source is free. See this thread comparing the energy in a barrel of water with that in a barrel of oil.

20

…climbs up the stairs of her building, muttering “Oil power plant…damnit…”…

…opens the door at the top, and rests near the ledge on the roof, twitching…

…opens the rifle case, and starts assembling gun…

…fixes scope…

…loads magazine…

…takes aim to sight weapon, muttering “I told them…bastards…oil power plant…teach them all.” …

…Cries out “I am the Angel of Death! The time of purification is at hand!!!”, then notices the following:

…sighs, then unloads gun, starts putting it away…