It looks to me like all of those windmills would slow the earths rotation.
[morbo]windmills do not work that way![/morbo]
The mills pushed by the Easterlies are cancelled by those pushed by the Westerlies.
Perhaps more interesting would be the destruction of flying critters. While this might contribute to the survival of the fittest, wiping out birds and perhaps increasing the insect population could lead to Darwin only knows what. Affecting one small part of the ecology tends to affect other larger and more complex parts. Safe to say that government will move ahead without much forethought, given that the Washington wind machine operates without being connected to any significant brain power.
The trouble with this answer is that it overlooks one of the major negative points of windmills – they only work when the wind is blowing. Electrical grids have no storage ability. Trying to run a whole country on wind power would simply mean that the grid voltage would oscillate wildly and render the supply of power unuseable. Fluctuations cause fuses to blow and create blackouts. You would face the problem that the time when winds are at their lowest ebb (mid summer, mid winter) is also the time of highest demand. Wind farms this big will never be built because they would be economic suicide.
I don’t really think we have to worry about this, because, as implied previously, all windmills don’t face in the same direction. But French TV had an april fool’s news report that said something like: Nowadays, with so many windmills in place and being installed, the Earth’s rotation is slowing down, and there will soon be 25 hours in a day. It then went on (if memory serves me well) with a clockmaker complaining about having to change the design of all his clocks.
Obviously, this is far-fetched, but engjs and fredricwilliams do raise good points.
Regarding the latter, while it is something that should be kept in mind, I don’t think there will be a single windmill farm big enough to misbalance a whole ecosystem (or, at least, not for the time being, and in the meantime, some kind of authority might take concern about this issue before it actually becomes a threat).
Regarding engls’s point, there are ways to store energy, and therefore to balance the times when winds blow and don’t. But otherwise, nobody has talked about making the whole electrical grid work on wind power, only part of it (for instance 50%). So, whenever winds are low, “switch” to the other power source (whatever it may be).
Generally speaking, although I do appreciate greener energy, I don’t think it’ll be a major part of our energy generation anytime soon. And, however we do it, it’s important to maintain a smooth transition between non-green and green energy, and maintain an ongoing balance as the transition moves along, even if it means that we produce some excess energy.
Just my two cents…
Only if you make them really, really tall and extremely massive.
This makes lots of assumptions that I don’t think would become true.
For one thing, no matter what types of power we add to the system, the electrical grid will have to be upgraded and modernized. It’s a patchwork mess today, true, and there is no true national grid, since it is split into three pieces. Even so, the current grid can handle power fluctuations. We know that since they happen all the time as individual power plants come on and off line. It happens even when there is a failure in the system, given that a plant fails frequently somewhere in the nation but blackouts almost never occur.
An upgraded grid will surely be planned for the fluctuations in power that occur because wind and solar are unpredictable. In the long-term, storage is also less of an issue than it is now. A variety of pilot programs are looking at storage, whether banks of capacitors or heating water during the day to use as the power source at night.
Nor is the variation in wind that much of a problem with a true national grid. The U.S. is an incredibly huge country. There is no moment at which the entire country is seeing high winds or low winds. There is always a blend from region to region and even within regions. A true smart national grid could easily cope with this.
As for slowing the rotation of the earth, NASA estimates there are over 400 billion trees on the planet. And many millions of buildings. And, oh yeah, a whole lot of mountains. A few million windmills wouldn’t be a rounding error.
Welcome to the Straight Dope Message Board, Hazy, we’re glad to have you with us. When you start a thread, it’s helpful to others if you provide a link to the column you’re commenting on. Yeah, it’s this week’s main question, but in a few weeks it will sink into the Archives. So, a link saves searching time and helps keep us all on the same page. I’ve edited one into your opening post.
No biggie, you’ll know for next time. And, as I say, welcome indeed!
I’ve wondered about this in the past, but my bigger question concerns solar energy. Would capturing and converting to electricity a non-infinitesimal portion of incoming solar radiation cause climate change?
I’m a little disappointed that neither Cecil, nor the commentators address the original question. I understand the question to be about the type and magnitude of climate change to be expected from wind power. How does it compare to global warming from fossil fuel burning? What happens if winds are slowed over large areas? Does it affect crop production? Would cities get hotter? What are the negative / positive effects?
Instead we have discussions of the visual impact and whether it works or not. Certainly it works, it is possible to manage in the grid, can be stored and is economically viable, as evidenced by machines being there.
Exapno Mapcase: “the current grid can handle power fluctuations”
Er, no. As I said, there is no storage capability. The incoming power must balance the outgoing power, or the voltage fluctuates up or down. If the voltage gets too high or too low, fuses blow and there is a blackout. If they didn’t then electrical equipment would be destroyed. For every power grid there is a man who stands and watches a board showing how the voltage is changing, and his job is to tell stations to come on line or go off line to balance demand. If he gets it wrong, there are blackouts. There is, as far as I know, no technology that can add storage to a power grid; if there was it would be being used. Maybe one day they will invent some, but that’s not going to be next week.
“There is no moment at which the entire country is seeing high winds or low winds.”
But the power from those winds varies from moment to moment quite considerably; there is no moment when the power is steady. Power grids work because the guy running the show can turn power stations on and off to balance the load. Because coal stations and nuclear stations and so on provide a fixed amount of power when switched in. Wind farms don’t, and that creates feedback.
The simile I’ve seen is that managing a power grid is like driving a bus down a winding road at night with very poor lights. Adding variable power sources to the grid is like giving all the passengers their own steering wheels. It makes a hard job into an impossible one.
OK, I see what you’re saying and where your problem is.
First, let’s deal with today’s world. Of course there are people in central control stations that handle the incoming power on a moment by moment basis. And yes, they have to handle fluctuations in the amount of power or else that will cause problems. But what you’re leaving out is that the usage, the load, also varies on a moment by moment basis, and far more so than the incoming power. It’s a delicate balancing act to keep the two even, true. But it’s been a known problem since Edison did the first city station in the 1880s. The entire system is set up specifically to handle variation.
What saves the system is that the variation at any given time is small proportional to the total, supply or demand. Loads are - and have been since the earliest days - analyzed obsessively to determine when peaks or spikes are likely to occur. Small percentage variations can be handled and obviously are, because they occur every second of every day and yet our appliances all work. (Those with the most delicate and sensitive equipment in fact do need to smooth their power from the lines. Again, this is a known problem and everyone acknowledges it.)
Wind power is currently too small a percentage of the total grid to cause the system to hiccup. I mean, we’re talking about a world in which 7% of the power is lost from the lines themselves. The system better be able to handle small percentage variations.
What about the future? Will this be a more serious problem if the percentage of wind-generated power grows to 50% of the total? Again, obviously yes. But nobody expects wind to grow to that percentage, probably ever. And the hidden assumption is that the system itself wouldn’t change and adapt in the future just as it has changed and adapted every day since 1882. Everybody in the industry is feverishly working on storage. (Flywheel storage is the next big thing, I’m told.) But it certainly does exist at small scale, and in the usual variety of forms that any infant industry takes. Everybody in the industry is feverishly working to upgrade the grid. Everybody is working to lower line loss. Loads can be added and shed faster than ever before now, and will be even faster in the future, because everybody is working on it.
Yes, the problem is hard. It may be harder than creating the current grid, although that history is so filled with overcoming seemingly impossible obstacles that whether hard or harder it will be done. We solve problems that we have no choice but to solve, and we always have solved electricity problems. I’m not usually the optimist in a discussion, but since the work is already being done and the changes have already started to happen, I don’t agree with your pessimism.
Power variation from windmills doesn’t seem to be an insurmountable problem. Simply using multiple sites spaced far apart eliminates much of the concern. From here (bolding mine):
Of note, Figure 2 in that link shows the correlation of wind speed as a function of distance, with correlation below 0.2 by 750 km separation.
Further, from here:
50 percent certainly isn’t “modest”, but we’re nowhere near that now, and presumably growth to it would be gradual, allowing the designers and operators to gain experience as the amount of wind power increases.
And there is such a thing as power storage, anyway; at the very least there’s reverse hydro.
Another question not addressed here or in the column is what effect turbulence caused by windmills will have on the weather.
Cecil mentions a little bit when he says:
I wanted Cecil to include more impacts on the weather in his column. Cecil disagreed with me and wanted to talk more about other aspects of the question. However, I’m sure he wouldn’t mind me elaborating upon it here. I hope this shall be useful to folks. From my notes when I was helping the Big Guy out…
Studies of a smaller virtual wind farm in Oklahoma of 10,000 turbines predicted the turbine blades would disrupt air near the earth’s surface, leading to the soil both warming and drying out. This could be a big factor for crops, since due to their small footprint wind turbines are pushed as having a good coexistence with farmland.
There’s a lot of interest in offshore wind farms to take advantage of the higher, less obstructed winds over the ocean’s surface. A conceptual study of a 3,475 square-mile offshore Dutch wind farm found one possible unintended side-effect: clouds were more likely to form on normally clear days, and rain tended to move from the coast to over the sea.
Researchers from Stanford University compared the total atmospheric energy loss from several different wind energy scenarios, even looking at a “worst case” of replacing the entire world fossil energy generation with 10 million wind turbines. Their conclusions: even the worst-case scenario required less than 0.08% of our total atmospheric energy. However, since we use so much more energy in the US we might lose 0.23% of the atmospheric energy over our mainland. This was still an insignificant amount when compared to the atmospheric disturbance from a doubling of atmospheric CO2.
That last note on CO2 is an important piece of the puzzle, and possibly another unintended side-effect of not reducing global climate change. Wind energy is directly linked to the climate, and if global warming leads to significant changes in atmospheric energy over the years – big problem. If the winds change you can’t just pick up 1,000 turbines and move them over to the next State, and that’s even assuming things are better over there. Some estimates show that the overall wind energy potential of the US could drop by 10% or more by 2050, although selected regions could see boosts in wind energy. A Canadian simulation predicted 30-40% reductions in wind energy by 2095. China, one of the big up-and-comers in wind energy, could also be seriously impacted: in the last two years average surface wind speeds were lower than they were in the 1950’s and 1960’s, and due to climate change impacts it’s predicted that by 2070-2100 the average Chinese wind speeds could decrease by as much as 12%, leading to even greater wind power reductions.
Fairley, Peter. “A Less Mighty Wind” IEEE Spectrum (January, 2011): 9-10.
Maria, Magdalena R.V. Sta. and Jacobson, Mark Z. “Investigating the Effect of Large Wind Farms on Energy in the Atmosphere” Energies 2 (2009): 816-838.
Rooijmans, Pim. “Impact of a large-scale offshore wind farm on meteorology: Numerical simulations with a mesoscale circulation model” Thesis. Utrecht University, The Netherlands, 2004.
Roy, S. Baidya, Pacala, S.W., and Walko, R.L. “Can large wind farms affect local meteorology?” Journal of Geophysical Research 109 (2004).
Wilbanks, Thomas J. et al. Effects of Climate Change on Energy Production and Use in the United States U.S. Climate Change Science Program Synthesis and Assessment Product 4.5, 2008.
Regarding power storage, could it be an option to use “excess” electricity to crack H20 and retain the hydrogen for combustion to generate energy during periods when the wind don’t blow or the sun don’t shine? It’s so simple I suppose there must be a simple reason why not–gross inefficiency? Or it’s not as simple as I think? Does anyone know?
In principle that could work, but in practice there are more efficient ways of storing energy. And even most of those still aren’t practical enough, in many cases.
This just begs the question, “How soon will tidal motion power generators pull the moon into New York?”