I guess I'm still not convinced. The power per unit would seem to be an attractive figure if it weren't for that fact that to reach truly significant numbers (approaching 10% of power needs, I would say) it requires just so damn many of the things.

And each one has to be pretty carefully maintained. It's not just subsidies that wind power receives, but very, very generous depreciation rates as well, which means that companies get to write the things off as approaching the capital equivalent of garbage faster than most forms of energy (compared to solar cells and coal plants, or just about any other). They're particularly finicky because of the stress on weldments, so they do actually take a lot of beating and wear out quickly.

How expensive would it be to replace 300 of the things that have been anchored to the sea bed off the Texas coast, or Nantucket, or Miami? The cost to build one isn't the same thing as the cost to ensure constant energy from that source. I'm certainly no expert as my thoughts show, but I still haven't seen anything about the real considerations of maintenance and consistency of power output.

I don't think people are suggesting that these things replace the power base for the country (which remains resolutely coal-driven), just that they can provide an efficient source of support. I'm skeptical of that, though. After all, the wind doesn't blow as constantly as coal can be burned in terms of duration and velocity. The irregularities in wind power harvesting put a limit on its usefulness in the overall grid, I believe, that is more of a hard ceiling than the cost per wattage that people seem to think is the key.

I'm all for renewable energy, but this just isn't convincing. Championing the creation of something as though it's going to simply work in perpetutity from now on seems disingenuous. I have to think that cost of upgrading coal and nuclear facilities per unit of output is dwarfed by that of wind farms. We can erect a long stretches of 3 MW turbines across farmland (which, incidentally, requires large areas of open land to use the automated watering systems you see driving through any ag-drive state, which seems to me to argue against the small-footprint benefit of wind turbines), but what happens when we want to incorporate 4 or even 5 MW ones? Just build more, though maybe smaller, wind farms elsewhere? Upgrading coal plants doesn't require as much increase in acreage as does the building of more and more windfarms as we adopt new turbines and leave old ones behind.

Again, I'm not at all an expert. Just some thoughts on the subject.

Some very good thoughts, Ian, and thanks for sharing them. Simon?

Given the instability and hostility in the energy exporting regions of the world, as a mater of national security the US, perhaps as part of the miltary budget, should be spending 10-20 billion a year on alternate energy research. We put a man on the moon and have phones that can take picture, you would think that in ten or 20 years we would have the issue resolved with cheap alternate energy.

Dunno, ZB. We put a man on the moon how many years ago? Got the technology down, all right. But is space flight cheap yet? Nope.

It will take a number of other advances in related to get us to cheap. Think about the effect of self-assembling nanotechnology improvements on solar cell efficiency and cost, for instance.

Ian, you have hit the nail on the head. The biggest problem with wind, as well as pretty much all renewable sources, is reliability.

Because the wind isn't always available to provide for the grids needs, you must also build a natural gas plant to make sure you can meet loads when the wind isn't there.

Hydrogen fuel cells could potentially eliminate this problem, by using electrolysis to generate hydrogen for the fuel cells at times when the full capacity of the wind farm isn't needed, but fuel cells have a ways to go before that can become a viable option.

I'm glad we're looking at renewable sources. I just wish all sides would take a pragmatic approach, and admit what they can and can't do. Then we could make some real progress.

There are two 660 kilowatt Vespa turbines near where I live. If the spacing between them is typical then I figure a line of equally spaced turbines would produce about 10 megawatts per mile. That's a lot of miles of turbines to replace even a modest (250 megawatt) power plant.

It's a pipe dream to think that wind can ever make up a large percentage of our power. Don't get me wrong, I'm all for renewable energy, but I'm an engineer too. Here's the deal:

The power grid has to balance. You have to put in as much as you're taking out at any moment. The power companies have very complex procedures for estimating demand over the course of the day and bringing generation capacity online to exactly match demand. You can't just flip a switch and turn on a plant in a second, either, it takes a while to get a plant online.

Wind energy is fine, but it VARIES. A front comes through and the turbines spin up like crazy. It can be windy one minute and not the next. You'll get some help by spreading them out geographically, but, statistically, you're still going to have that odd momemnt when a bunch of wind energy just goes away for a few minutes. How do you suddenly, within a minute or so, add a 100 megawatts to the grid? And how do you plan to bring on your generation capacity when you can't predict how much power the wind turbines will be producing an hour from now?

So far, I don't think anyone has an answer, except for batteries, which isn't really an answer. Also, how is it economical to have all the turbines when you also have to have an equal amount of conventional generating capacity sitting around idle to take care of days when there's no wind?

Interesting comments Rob.

I talked to a Gubernatorial candidate at UCSD who is running on a wind platform. His plan was to put 1,000,000 generators off the coast. His claim is they would provide for all of the energy needs of the state.

He solves the variability, storage, and transmission problem by producing hydrogen which, he says, would be pipelined back to shore.

It sounds pretty fanciful to me. But, implementation issues aside, there are two things that bug me about it:

First, the turbines are eyesores. There's no way around it. Driving out 580 from the bay area you see hundreds (thousands?) of hideous turbines blighting the landscape. Same for I-10 going towards Palm Springs. Are the benefits of wind power worth the aesthetic damage to California? Do we want to ruin the desert or coastal landscape by pock-marking them with wind turbines?

Second, what about environmental impact? Using wind for a significant percentage of the country's power needs would require a huge number of turbines. Transferring power out of air currents, obviously reduces the force of the wind. How will this affect climate and pollution? Will it reduce pollen and spore transfer? Will it affect bird migration and soaring? Will it reduce the quality of surf on the California coast?

What about hurricanes? Not in CA, I know, but on the EC and TX?

Would they be strong enough to resist Isabel at full strength?

i live in southeastern michigan. i either have sunlight or i have wind. my idiot neighbor has a tiny windmill in his backyard. it's to look at, not to do anything. but it spins wildly almost every single day of the year. the blades are positioned about 5' off the ground. it wouldn't take a great deal to pump electricity from that device as small as it is.

feasible? absolutely. so is solar power. particularly if we create solar panels which work off of radiation, not just direct sunlight, because we have radiation which penetrates most cloud cover as well. why not use it? it's free. the equipment isn't, but it would pay for itself.

i have a garden hose attached to the faucet on the south side of my house and as long as it is warm enough, it stays attached. throughout the summer, the water in the hose gets extremely hot -- too hot to touch when it sprays out. and right now in the fall? it's still quite warm. and it's warm on days when it's not 40 deg F outside. (yes, i'll disconnect when it drops below freezing, it'd be stupid not to). but the point is, that if sunlight can create this much stored heat, it can easily do the same intensity of electricity -- year round.

we're better start developing these sources as burning wood is rapidly increasing the numbers of people with asthma and other health problems. wood has the same chemicals as tobacco and the chunks we burn are much larger and just as dangerous as a tiny cigarette.

i have neighbors who burn. and on days when there's an inversion or a thick layer of clouds or fog, the smoke does not disperse. my dogs have developed breathing problems and can't go outside on those days. neither can i.

The needs of the grid pretty much relegate wind generated electricity to a supplementary role. No bad thing when you consider what it costs to add marginal capacity to a grid; but because of the variability of the output of wind even that role has to be discounted.

When it comes to alternative energy I am inclined to think the most feasible alternative is geo-thermal in all of its many manifestations. Not for electrical generation but rather for home heating and water heating. Dig six feet down and you hit a constant temperature zone. Run pipe through that zone and hook it up to a heat pump. Effectively you can heat your house for the cost of the installation and a few dolars a year in the electricity cost of the heat pump.

Were we to provide tax incentives to offset the capital cost of the trenching and heat pumps and set a goal of retrofitting half a percent of the housing stock, there could be a huge dent made in the consumption of natural gas, oil and electricity.

The beauty of geothermal is that it works in reverse: in summer rather than turning on the electrically powered air conditioner, you flip the heat pump into reverse and such heat out of your house and into the ground. The reduces the peak loads experiences during heat waves and, in turm, reduces the need for additional generation capacity.

Best of all, the technology to implement geothermal exists right now.

I've been out of town for a few days so excuse the delay.

The foot print of a wind turbine in terms of agricultural land is on the order of 1/2% of the area required due to spacing requiremwnts. Not very significant.

As far as farmer acceptance: they like it. At about $2,000 per year royalty (1.5MW turbines) it pays better than farming. The fact that it's interference with farming is minimal is a big plus.

Upgrading a coal plant is not easy. New boilers, turbines and other machinery. Plus more coal to transport. Plus coal plants are very high maintenance. It is why you don't see small steam turbines burning farm waste for electric power. It is why you no longer have individual generators on farms for electric production. It is not cost effective.

The move to larger turbines is also a help re-maintenance. It takes very little extra maintenance to maintain a 1,500Kw turbine vs a 500Kw turbine.

As to depriciation: it is a tax thing. (Robbery by government). Take it up with your politician.

BTW old turbines are not left behind as long as the electrical power from them can be sold at a profit. If you look at what happened at Altamont Pass in Calif you can see the progression. The turbines there have been upgraded over a twenty year period. As the old machines became unproductive they were replaced.

The reliability issue:

Reliability is not as big a problem as you think. The problem is that people think of individual turbines not statistical aggregates.

Currently wind project costing is based on about 1/3 the nameplate output over time. Thus a 1.5MW job would be expected to produce 500Kw average the year around. This does not tell the whole story. When you start getting large numbers of turbines distributed over large areas you can count on a 20% of name plate rating for the base load. What that means is that by building about 50% more turbines than would be required on from an available energy point of view you can cover the base load with very cheap power available as excess capacity.

With wind prices based on learning curve estimates going to 1/2 of a base load coal plant or less over the next twenty years, building the excess capacity required to cover the base load will not be an economic problem. The question then becomes what to do with all the leftover energy (equivalent to 50 of total required electrical power)? Making hydrogen for cars or perhaps methanol will be a good idea.

The thing is that at this point the process cannot be economically rushed. We need to add wind capacity at a rate that increases turbine production by 30 to 50% a year and a doubling of turbine size every three to six years.

Currently with wind amounting to less than .1% or so of total electrical load there is going to be enough time to work out the issues. It will be 7 to 10 years before we are even up to 1%. By then we should know a whole lot more.

Fred,

Turbine spacing is minimum 6 turbine diameters and better 10.

What you fail to note is that turbine power goes up at the square of the turbine diameter. That means that doubling blade length doubles the amount of power that can be extracted from a given ground area. Turbines do not extract energy from a line or an area. They extract energy from a volume.

Since the farther from the ground you go the higher the wind speed the gain is actually greater than double.

Rob,

I wrote an article you might like to read on grid balance and negative resistance loads re: the New York blackout. It is here:

*Power and Control*

I understand the balance question. At low percentages of wind (under 20%). It does not seem to be a problem. Wind is dispatchable in 1/2 hour increments. A nice match with the gas turbines. By instrumenting an area we can get a pretty good idea about wind capacity several hours or more in advance.

What is needed once we get to higher capacities is interruptable loads (such as hydrogen gas production) or storage such as super flywheels. Ballard has a 250 KW rated 250 KWh storage machine in the prototype stages. In 15 to 20 years when we will need significant storage or interruptable loads they will be there.

All this will be worked out over time. Life is one big differential equation. Or as we like to say in the physics community "the reason there is time is so that everthing doesn't happen all at once."

pseudoDub,

Beauty is in the eye of the beholder. I think rows of large semi-mobile sculptures moving with the wind that also produce energy are a thing of beauty. There is one on I-80 in Iowa that is very pretty. I stopped and looked at it for quite some time while passing through.

What you are in effect asking for when you look at all the problems wind energy may cause is a perfect world. I can't offer you that. Only a better one.

You have to decide which is better for the planet: coal burners or wind plants (given equal costs). My vote re: better is for wind. You may have a different balance point.

The best technology evolves over time. We are on the way. There is no rush.

cris,

Radiation is a good idea. Unfortunately the energy is not of very high quality. You need a wavelength just around red or shorter to use to produce free electrons (with known technology & science).

I think your questions expemplify a serious failing in our school systems in that they do not even teach well things that have been known for over 100 years (the Einstein effect is what you have unknowingly refered to). Band gaps and Fermi levels have been an important part of all this since the invention of the transistor and solid state laser. Yet it is not even covered in the most rudimentary fashion.

Oh well.

Jay,

Excellent point about geothermal. It also serves as a way to shift thermal energy between seasons. In summer you are pumping heat into the ground. In winter you are "pumping" cold into the ground (extracting the summer heat).

The problem is capital cost and lack of knowledge.

Considering payback the capital cost is not excessive.