Is there a limit to wind power?

[Andrew Mason]

If nuclear costs raise concern, see transmission costs for intermittent power. The most recent advanced transmission line completed in N. America was the West Alberta Transmission line: 500 kv, HDVC, 1 GW, 350 km, $1.7B, or $7 million per GW-mile. Imagine then, replacing a US east coast nuclear plant, perhaps the 4 GW nuclear plant completing construction in Georgia, where there's little wind resource, with transmission to ample (but intermittent) US mid-west wind. Average US wind capacity factor is 33%, so that the line must support 12 GW of wind power while it blows to replace the average of the nuclear plant. Distance is some 850 miles, so total cost based on the most recent installed technology is $23 billion, requiring right of way for perhaps six different lines across five states.

All fair points, but these are not overwhelming problems. You don't have to build the windfarms all in one place so why would the distribution lines have to have such high capacity? Why would you need 850 miles of transmission line to connect a windfarm to the grid?

AM

 

[mheslep]

All fair points, but these are not overwhelming problems. You don't have to build the windfarms all in one place so why would the distribution lines have to have such high capacity? Why would you need 850 miles of transmission line to connect a windfarm to the grid?

AM

Existing transmission capacity is finite, which services existing need. In the scenario I used, if 12GW additional flow is required, then additional transmission must be built.

 

[anorlunda]

All fair points, but these are not overwhelming problems. You don't have to build the windfarms all in one place so why would the distribution lines have to have such high capacity? Why would you need 850 miles of transmission line to connect a windfarm to the grid?

AM

Don't forget, new transmission lines take more than just money. They need large areas of land, called "right of way". Simetimes, the land must be obtained by force (eminent domain). The process typically generates one lawsuit per mile.

For several decades, US utilities have been trying to live with the land already used for transmission lines. They figure that in the future, very little or no additional land will be available to them.

The number one flaw in the thinking of people who dream of new and better ways to generate and deliver electricity is failure to appreciate the problems of scaling up to meet the bulk demands for power. The number of plants, the numbers of lines and the amounts of energy, and the reliability of supply demanded exceed their imaginations. Clever innovations are a dime a dozen, but making one work on the scale required is very difficult.

 

[Andrew Mason]

50 years ago the experts would have given us 50 reasons why the Dick Tracy wrist video phone would never be possible or, in any event, practical. 50 years from now, I predict that people will see the arguments against renewable power the same way we see those.

These are problems that can be solved with political will and money. Windfarms are cropping up all over the place and the utility companies who put them up are finding ways to get access to the land . The windmills are spread over dozens of farms which all feed into a local station from which the power is transmitted to the grid. All I am suggesting is that we make the grid world-wide so that the US has access to solar power from the Sahara to charge our electric cars overnight.

AM

 

[jbriggs444]

All I am suggesting is that we make the grid world-wide so that the US has access to solar power from the Sahara to charge our electric cars overnight.

Arguing on the one hand that 850 miles is an unreasonable distance to transmit power and on the other hand that piping power from the Sahara to the U.S. is reasonable does not help your case.

 

[OmCheeto]

I don't imagine one wind farm would matter much, but if people are getting Terawatts from wind it's a bit worrisome. I hope someone has done studies on this.

I'm sure lots of studies have been done. I can't find the webpage I looked at yesterday stating that one study says there would be little effect, and another study says there would be disastrous effects. Everyone has their model.

Here's one from MIT done almost exactly 5 years ago:

Wind resistance
MIT analysis suggests generating electricity from large-scale wind farms could influence climate — and not necessarily in the desired way.
Morgan Bettex, MIT News Office
March 12, 2010
...
According to Prinn and Wang, this temperature increase occurs because the wind turbines affect two processes that play critical roles in determining surface temperature and atmospheric circulation: vertical turbulent motion and horizontal heat transport. Turbulent motion refers to the process by which heat and moisture are transferred from the land or ocean surface to the lower atmosphere. Horizontal heat transport is the process by which steady large-scale winds transport excessive heat away from warm regions, generally in a horizontal direction, and redistribute it to cooler regions. This process is critical for large-scale heat redistribution, whereas the effects of turbulent motion are generally more localized.
...

 

[Evanish]

50 years ago the experts would have given us 50 reasons why the Dick Tracy wrist video phone would never be possible or, in any event, practical. 50 years from now, I predict that people will see the arguments against renewable power the same way we see those.

These are problems that can be solved with political will and money. Windfarms are cropping up all over the place and the utility companies who put them up are finding ways to get access to the land . The windmills are spread over dozens of farms which all feed into a local station from which the power is transmitted to the grid. All I am suggesting is that we make the grid world-wide so that the US has access to solar power from the Sahara to charge our electric cars overnight.

AM

Electronics have advanced by making things smaller. You are talking about making something much bigger. The cost of building such a huge and complex machine is hard to imagine. I'm guessing the cost of maintaining it wouldn't be cheap either. Compared to this nuclear power seems cheap and easy.

 

[Andrew Mason]

Arguing on the one hand that 850 miles is an unreasonable distance to transmit power and on the other hand that piping power from the Sahara to the U.S. is reasonable does not help your case.

The idea is that regional grids would be linked to continental grids which, in turn, would be linked to a world grid. The grids are not just for wind power - they are for all power. So no one needs to build an 850 mile transmission line for a single windfarm.

Electronics have advanced by making things smaller. You are talking about making something much bigger. The cost of building such a huge and complex machine is hard to imagine. I'm guessing the cost of maintaining it wouldn't be cheap either. Compared to this nuclear power seems cheap and easy.

The links between continental grids could be large underground conductor paths. Those should have manageable maintenance costs. The idea is to build permanent infrastructure that would serve as an electrical grid that could last for perhaps hundreds of years. We do build things like that: canal systems and tunnels, for example.

Nuclear power in its present form is not sustainable. Even if we had enough U (which, based on present reserves and present consumption will meet demand until about 2050), the problems with decommissioning and spent fuel have to have simpler solutions. Perhaps the self-contained fast reactors would solve some of those problems and could allow us to use nuclear for another few hundred years. It takes 20 years to develop a nuclear plant. And it takes another 20 to shut one down. Fusion, if it is ever developed and becomes practical, would take even longer to develop and there are still huge shut-down and decommissioning problems and you are still left with radioactive core containment materials that won't be safe to go near for hundreds of years.

In 20 years we can build enough solar and wind to replace every coal plant in the US. We just have to use our imaginations to make it practical and make it work with other renewable energy sources such as hydro and biomass.

AM

 

[jbriggs444]

The idea is that regional grids would be linked to continental grids which, in turn, would be linked to a world grid. The grids are not just for wind power - they are for all power. So no one needs to build an 850 mile transmission line for a single windfarm.

Grids are not magic. You cannot sink a 12 gigawatt power surplus without budgeting for 12 gigawatts of excess transmission capacity to an available power sink.

 

[mheslep]

In 20 years we can build enough solar and wind to replace every coal plant in the US.

As I explained above, solar and wind as they exist now can not replace coal plants. Natural gas, nuclear, biomass, geothermal, hydro: these all can replace coal and do. Solar and wind can make coal plants run less, but not replace them and close them down. The cost of maintaining both systems side by side is, as shown Germany, very expensive.

other renewable energy sources such as hydro and biomass.

Reliance on biological sources for energy and materials in the past often led to their near extinction: forests, buffalo, whales. While fossil fuels have their own problems and there are reasons enough to limit their use, their introduction allowed forests to regrow where they had been nearly obliterated, e.g. most of the east coast forests of the US in the 19th century. A repeat of the mistakes of the past is comical as far as its currently gone; keep it up though and the comic might become tragic.

 

[mheslep]

Even if we had enough U (which, based on present reserves and present consumption will meet demand until about 2050),

90 years at the current rate of 66,000 tU/yr, using only reserves known today, using only U-235 thermal spectrum reactors. Known U reserves have been increasing for decades. Switch to fast spectrum reactors and the usable fuel supply increases by 100 times. Then there's the ocean content, then there's thorium.

 

[Evanish]

Nuclear power in its present form is not sustainable. Even if we had enough U (which, based on present reserves and present consumption will meet demand until about 2050), the problems with decommissioning and spent fuel have to have simpler solutions. Perhaps the self-contained fast reactors would solve some of those problems and could allow us to use nuclear for another few hundred years. It takes 20 years to develop a nuclear plant. And it takes another 20 to shut one down. Fusion, if it is ever developed and becomes practical, would take even longer to develop and there are still huge shut-down and decommissioning problems and you are still left with radioactive core containment materials that won't be safe to go near for hundreds of years.

Breeder reactors can been done, have been done and should be done more in my opinion. Decommissioning and nuclear waste are small problems compared to something like building a world wide electric grid.

 

[Andrew Mason]

As I explained above, solar and wind as they exist now can not replace coal plants. Natural gas, nuclear, biomass, geothermal, hydro: these all can replace coal and do. Solar and wind can make coal plants run less, but not replace them and close them down. The cost of maintaining both systems side by side is, as shown Germany, very expensive.

I agree, so long as wind and solar are highly variable or intermittent. All I was suggesting is that if we combined all solar and wind into a world-wide grid, that would not necessarily be the case. There is always sun shining and wind blowing somewhere on the earth.

Reliance on biological sources for energy and materials in the past often led to their near extinction: forests, buffalo, whales. While fossil fuels have their own problems and there are reasons enough to limit their use, their introduction allowed forests to regrow where they had been nearly obliterated, e.g. most of the east coast forests of the US in the 19th century. A repeat of the mistakes of the past is comical as far as its currently gone; keep it up though and the comic might become tragic.

Biomass is just a way of storing solar energy. You raise some legitimate concerns. But saying it is difficult does not mean it can't be done. I am not prepared to accept, at least right now, that with careful management, biomass could not be used to generate electrical power. I'm just saying that along with hydro, wind, solar, it could be used to supply all of mankind's electrical energy needs.

AM

 

[Andrew Mason]

Breeder reactors can been done, have been done and should be done more in my opinion. Decommissioning and nuclear waste are small problems compared to something like building a world wide electric grid.

I would like to have seen the US proceed with the Integral Fast Reactor because it does provide a reasonably acceptable solution to the spent fuel problem. It has its own operational challenges - e.g liquid metal cooling. Assuming those are solved, it still leaves the decommissioning problem. But it was canceled and we may never get there.

In the long term, however, we have to use the energy from the sun. It will last as long as there is life on earth. It would be a challenge to make it work but it will work. It is not as if we have to commit huge resources to wind and solar all at once. But if we don't make it an important goal, we will never find the solutions to all the problems it faces.

AM

 

[Evanish]

I would like to have seen the US proceed with the Integral Fast Reactor because it does provide a reasonably acceptable solution to the spent fuel problem. It has its own operational challenges - e.g liquid metal cooling. Assuming those are solved, it still leaves the decomissioning problem. But it was canceled and we may never get there.

In the long term, however, we have to use the energy from the sun. It will last as long as there is life on earth. It would be a challenge to make it work but it will work. It is not as if we have to commit huge resources to wind and solar all at once. But if we don't make it an important goal, we will never find the solutions to all the problems it faces.

The breeder reactors that we can be built today are good enough in my opinion sodium coolant and all. We should start building them now. We likely won't, but we should in my opinion. In the long run breeder reactors could power civilization for millions if not billions of years. That seems long term enough to me. I've spent a good number of years reading about this subject. It has not left me with much confidence in wind and solar. I'd feel much safer if we were building nuclear instead, but I seem to be outvoted (in western society at least) so I guess I'll just have to wait and see. I am a bit curious why you think decommissioning is such a big issue.

 

[Andrew Mason]

The breeder reactors that we can be built today are good enough in my opinion sodium coolant and all. We should start building them now. We likely won't, but we should in my opinion. In the long run breeder reactors could power civilization for millions if not billions of years. That seems long term enough to me. I've spent a good number of years reading about this subject. It has not left me with much confidence in wind and solar. I'd feel much safer if we were building nuclear instead, but I seem to be outvoted (in western society at least) so I guess I'll just have to wait and see. I am a bit curious why you think decommissioning is such a big issue.

I'm not sure about your "millions" if not "billions" of years. The fuel consumption of a faster breeder reactor, assuming it can reprocess and eventually use all of its Uranium fuel, is about 1/100th that of current light water reactors. So you seem to be saying that nuclear power using current reactors would work for 10,000 to 10,000,000 years.

Decommissioning is a problem for sustainability. It is very expensive and difficult to dismantle and safely keep the core materials isolated from living creatures for the few thousand years that is required. You end up having to encase everything in concrete and seal off the site forever. We don't know all the details of decommissioning most of the current nuclear plants let alone the cost and feasibility of decommissioning one 50 years from now.

AM

 

[mheslep]

You end up having to encase everything in concrete and seal off the site forever.

Dozens of US nuclear reactors have been decommissioned, paid for by the industry. Here's the Maine Yankee plant before closing in 1996:

and after (overhead):

http://www.3yankees.com/images/thumb_002.jpg

 

[Evanish]

I'm not sure about your "millions" if not "billions" of years. The fuel consumption of a faster breeder reactor, assuming it can reprocess and eventually use all of its Uranium fuel, is about 1/100th that of current light water reactors. So you seem to be saying that nuclear power using current reactors would work for 10,000 to 10,000,000 years.

The amount of Uranium that can be recovered economically increases greatly when breeder reactors are used. Right now the lowest grade ore used has around 100 part per million uranium, but if we had breeder reactors that are one hundred times more efficient then current light water reactors we could go after ores that are 1 part per million. The Earth continental crust has http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Uranium-Resources/Supply-of-Uranium/ on average. Pretty much everything is potential ore when breeder reactors are used. There is something like 40 trillion tons of uranium in the Earth's crust. Recovering just a fraction of that, and utilizing breeder reactors, would supply billions of people with a decent life till things heat up and life on the planet ends. We don't even necessary need to mine it ourselves since it's water soluble. The oceans are full of uranium that could be recovered if we were using breeder reactors, and rivers wash more uranium into the ocean at a rate of 32,000 tons (page 165). More then enough to meet all the worlds energy needs. It's awe inspiring really. It's a shame most people don't seem to be aware of it.

 

[rootone]

Regarding wind power, yes there is a theoretical limit, since the total amount of energy involved in driving the winds is not infinite.
However the proportion of that energy extracted by current wind farms is insignificantly small.
Even if we were to cover the entire surface of Earth with wind farms we wouldn't get anywhere near to approaching the theoretical limit

 

[OmCheeto]

Regarding wind power, yes there is a theoretical limit, since the total amount of energy involved in driving the winds is not infinite.
However the proportion of that energy extracted by current wind farms is insignificantly small.
Even if we were to cover the entire surface of Earth with wind farms we wouldn't get anywhere near to approaching the theoretical limit

I agree. I've been watching the wind power density above my house over the last few days, and my rough estimates are that there is somewhere between 1 billion and 20 billion times as much power in the wind as humans consume.

x axis is elevation in meters
y axis is watts/meter²

low power day (3/17/2015 16:00 PDT)​

high power day (3/15/2015 13:00 PDT)​

Numbers are from over my house 45.6°N 122.6°W
Data collected from earth.
Surface area of Earth: 510 trillion m²
Earthling annual energy consumption: 5 x 10²⁰ joules in 2010

On a somewhat humorous, very coincidental side-note; at about the same time I posted the following the other day:

Though, a 10km tall, 440 km long scaffolding, strikes me as a bit of an economic/engineering problem. Not to mention, the wind is constantly shifting.

A wind storm hit my city, and knocked down a 30 meter tall scaffolding.
I was like; "Yup. We can't even build a 30 meter tall scaffold. Good luck with one 10,000 meters tall."

 

[Buckleymanor]

Regarding wind power, yes there is a theoretical limit, since the total amount of energy involved in driving the winds is not infinite.
However the proportion of that energy extracted by current wind farms is insignificantly small.
Even if we were to cover the entire surface of Earth with wind farms we wouldn't get anywhere near to approaching the theoretical limit

Should imagine you might approach some kind of tipping point. If only from the reduction in the Earth's rotational speed, building all them windmills some sixty feet in hight covering the entire surface will surely affect the angular momentum of the planet.

 

[anorlunda]

Should imagine you might approach some kind of tipping point. If only from the reduction in the Earth's rotational speed, building all them windmills some sixty feet in hight covering the entire surface will surely affect the angular momentum of the planet.

Not if half the wind component is East and half West. East-west and north-south components of wind approximately cancel.

 

[Buckleymanor]

Not if half the wind component is East and half West. East-west and north-south components of wind approximately cancel.

Nothing much to do with the wind component. The construction of the windmills is all that is required to effect the angular momentum.Hold your arms out when you spin and you go slower.

 

[rootone]

I doubt if would affect the rate of the Earth's rotation in any noticeable amount though.
Probably it would have less effect then that does the tidal effect of the moon, which is already very gradually slowing the spin.
A sixty feet tower is trivial in mass compared to the bulk of the Earth, and even thousands of them would not add up to making a lot of difference.

 

[Buckleymanor]

The post quoted mentioned covering the entire surface of the Earth with wind farms. I doubt that would add up to thousands of wind mills.There are limits to any system and the effects they produce.I agree a few thousand windmills would not make much difference but a few million windfarms might.

 

[rootone]

Well obviously it's not a realistic proposition that the entire surface could be covered with windmills,
but in terms of the difference it could make to angular momentum in principal, we would need to consider the total mass of construction material this would involve and what difference it would make to angular momentum when displaced by 60 feet.
Compare this then to effect of the mass of the moon displaced by 384,400 km (1,261,154 feet).

 

[Vespa71]

Windmills and solar are actual contributions to future electricity solutions. They are much smaller, and require a vast reduction in total consumption, if they'ra going to replace fossile and nuclear. Hydro will buffer solar and wind on the grid. Artificial hydro-drops will possibly buffer some.

 

[Andrew Mason]

Well obviously it's not a realistic proposition that the entire surface could be covered with windmills,
but in terms of the difference it could make to angular momentum in principal, we would need to consider the total mass of construction material this would involve and what difference it would make to angular momentum when displaced by 60 feet.

Perhaps you meant angular speed of the Earth rather than angular momentum?

Compare this then to effect of the mass of the moon displaced by 384,400 km (1,261,154 feet).

I think you meant: 1,261,154,856 feet.

AM

 

[rootone]

Yes the latter was probably just a pasting error, (I used an online calculator).
I referred to angular momentum because this was the term used in the preceding discussion, but yes angular velocity would have been the correct term.
My point basically was that I doubt it would be much affected by construction of windmills even in enormous numbers, and that the existence of the moon probably has an effect which is orders of magnitude greater, and even that is too small to make any difference over timescales in the order of a human life span.

 

[Buckleymanor]

Yes the latter was probably just a pasting error, (I used an online calculator).
I referred to angular momentum because this was the term used in the preceding discussion, but yes angular velocity would have been the correct term.
My point basically was that I doubt it would be much affected by construction of windmills even in enormous numbers, and that the existence of the moon probably has an effect which is orders of magnitude greater, and even that is too small to make any difference over timescales in the order of a human life span.

You are probably wrong about the consiquenceis if windmills were constructed in enormous numbers if you consider that the construction of dams in the northern hemisphere allready has a measurable effect on the angular speed of the earth.