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July 27, 2006

Comments

Jeff Olney

Texas is headed to over 3,500 MW capacity. AWEA.org shows Texas at 2370 MW, with 400 MW under construction. Several sites were left off the "under construction" list, including Mesquite (100 Gamesa 2MW turbines), and the rest of Horse Hollow Phase II. (100 2.3MW turbines). Camp Springs (130MW) and Buffalo Gap Phase II (230MW) will be starting shortly.

Jeff Olney
GE Wind Energy

Cervus

Of course, the difference between wind and other power generation methods is that with coal and natural gas you can increase output to meet demand.

I read an article in the Toronto Star last week that planners only factor in 10% of rated output for wind generators to be available during peak demand.

The downside? As Astle points out, wind can't really offer us a true capacity rating. Sure, we can say we're building a 100-megawatt wind farm, but that figure is assuming the turbines spin at optimal speed 24 hours a day or on request.

Let's take Ontario during the month of July. Last Thursday, for example, the output of the province's three operational wind farms, which at full output can produce 207 megawatts, only generated between 4 and 42 megawatts depending on the hour.

For most of the day last Friday, output was below 10 megawatts, working out to less than 5 per cent of "nameplate" capacity. So far this month the typical range is between 35 megawatts to 75 megawatts, with a top output of 157 megawatts achieved during a single hour.

This is part of the reason why power planning authorities, when factoring in the contribution that wind makes to the grid, only assume that an average of about 10 per cent of theoretical output will make it to the grid during peak times.

And that, I think, is wind power's problem in a nutshell.

Jeff Olney

Facts:

*ERCOT (The texas power grid) used the same capacity factor of 10%. They recently dropped that number to 1.9%.

*At low wind speeds (under 5 m.p.h.) wind farms frequently consume more power than they produce. (to keep electronics running, to yaw the turbines into the wind, etc.)

Wind power isn't intended to replace conventional power plants. The technology needed to store vast quantities of energy at a low cost isn't available yet--unless you live near a pumped storage facility.

Wind power simply takes advantage of the times when the wind blows to produce clean energy at an affordable rate. When the wind blows, fossil fuel plants produce less power, therefore consuming less fossil fuels.

Today's generators produce 30 to 40 percent of their capacity. (a 1MW turbine averages 300kw to 400kw production throughout the year.)

Jeff Olney
GE Wind Energy

amazingdrx

"The technology needed to store vast quantities of energy at a low cost isn't available yet"

Any news on superconducting energy storage Jeff? This would seem to be a possible solution to large scale energy storage, from variable renewable sources like wind and solar, given some financial support for a prototype.

GE just got a government grant to produce a floating offshore wind machine. A design a norwegian company has already perfected.

Wouldn't it be better for GE to use scarce capital resources to pioneer this energy storage technology instead?

As far as capacity factor, percentage of peak load, and other measures of wind energy devices beloved of wind power critics, aren't kwh per year and cost per kwh less confusing ways to define power output from wind? I believe wind power contracts are specified in these terms for just that reason.

Jeff Olney

I know nothing about superconducting energy storage. I work with wind turbines. :-) I don't work in R&D, and I don't decide how money is budgeted. I wish I did, but I don't.

Energy produced is left out of contracts because you can't guarantee how much the wind blows. Contracts usually state an operational percentage of a wind turbine during a specified period of time; a warranty-type contract on the machine itself.

I like your blog, amazngdrx.

Robert McLeod

Well this discussion has quickly moved into the realm of the negative aspects of intermittent renewables. Myself and others have suggested that introducing plug-in hybrids or some other form of deferrable power demand would greatly ameliorate the negative intermittent aspects of wind power.

I've made a couple of posts recently that are topical to this discussion, one on the proclivity of wind power:
http://entropyproduction.blogspot.com/2006/04/proclivity-of-wind-power.html

and this post on how wind and solar can work in a mix of other power sources:
http://entropyproduction.blogspot.com/2006/07/texas-power-mixer.html

I'm working to add deferrable demand to my model.

amazingdrx

Thanks jeff, keep up the good work. I for one appreciate your point of view from inside the industry.

I think more of that kind of reality check is needed, especially on us Jules Verne wannabes, hehey.

Ender

jeff - "Energy produced is left out of contracts because you can't guarantee how much the wind blows"

I thought you could pretty well with advanced weather prediction such as this:
http://www.djc.com/news/en/11146933.html
can greatly increase the reliability of wind power. Also dispersed wind farms are unlikely all to have no wind at the same time.

amazingdrx

Another factor in favor of wind Ender, the taller the wind machine, the steadier and stronger the wind.

I have tried to get wind speed data for 1000 feet with no luck. The tallest structure in america is a 2000+ foot TV broadcast tower in North Dakota.

I think 1000 foot wind machines on the great plains and on offshore floating platforms would be a solution to intermittent wind energy supply. As well as wave power systems, which would be steadier by the nature of waves.

And all the expertise gained with superconducting particle accelerators could be applied to utility scale superconducting energy storage systems. They already exist commercially for small scale storage for computer systems.

Without large wind and solar inputs to the grid it seems no one is interested in pioneering this technology. But because of load fluctuation alone these storage devices would save fuel even without adding wind and solar into the equation.

Another aspect is that with the grid integrated on a larger scale, fossil fuel backup plants could come online at full capacity, yeilding maximum efficiency, rather than backing up a smaller region and operating at some fraction of capacity.

Fossil fuel plants are inefficient at less that full output. The added fuel costs negate the savings from wind and solar.

Paul Dietz

Any news on superconducting energy storage Jeff?

It's still too expensive, last I heard.

A problem is that a large SMES ring's storage capacity scales as R log R (R the ring major radius, and for a given fixed conductor cross section), so there aren't strong economies of scale.

There's another concept, the magnetically confined kinetic energy storage ring, where the stored energy scales as R^2, but the ring and levitation systems size and cost scale with R. This is unlike conventional flywheels, since the centripetal force is carried by the Earth instead of by the flywheel material. IIRC the economics for this don't really work out until the ring is quite large, and there's also safety concerns if the levitation or vacuum systems fail.

amazingdrx

"there aren't strong economies of scale"

Off course when your electron "flywheel" has a light speed velocity, economies of scale may not be vital. The energy stored is proportional to the square of the velocity.

A lot of smaller energy storage rings would be fine. When a room temperature superconductor is found, even batteries in electric cars maybe replaced by this technology.

A lot of conspiracy theory advocates believe that the government already has in its possesion alien spacecraft that use room temp superconducting technology to provide artificial gravity drive, hehey. And that it is suppreseed because it would make every industry we have obsolete and its introduction would precipitate complete economic/political chaos.

"another concept, the magnetically confined kinetic energy storage ring"

This is interesting, using subatomic particles approaching a signifigant fraction of light speed the amount of energy stored could be very large. Here is another technology that could be extrapolated from particle accelerator experiments.

amazingdrx

http://72.14.203.104/search?q=cache:r6WldXvFZpcJ:www.amsuper.com/products/library/WPScs.pdf+northern+Wisconsin+distributed+SMES+units+stability+transmission+loop&hl=en&gl=us&ct=clnk&cd=1

Who'd a thunk it. My very own power utility compny here in Wisconsin has SMES!! I gotta do a blog article on it.

Chuck the Lucky

I find it hard to believe that there would be such an increase in wind power production and investment if it was really so uncompetitive. As for the intermittent nature of wind, that is what transmission towers and energy markets are for. Utilities are constantly making decisions on whether to bring certain plants up to full capacity or buy more power from neighbors. Intermittent wind is no different than variation in natural gas and oil and coal costs. People often seem to judge alternative energy sources as an all or nothing replacement for fossil fuels. None of them can compete under those criteria but neither can any single fossil fuel.

Harvey D.


Jeff Olney:

Height, good steady winds (good locations) and efficient (proper) wind mills can maintain surprisingly high power production vs designed capacity.

Do you have data on average power actually produced vs installed capacity for various sites or farms?

I've seems (some) figures as low as 5% (for poor locations) and as high as 45% (for good locations)

Why would anybody install wind farms in poor locations?

Jeff olney

Sorry I haven't responded--It's been a hectic week, and I haven't had the chance to check the blog.

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Harvey - I've seems (some) figures as low as 5% (for poor locations) and as high as 45% (for good locations)

5% = 1980's turbines (can't turn into the wind, can't change blade angles) and the lack of modern computer technology to place the turbines where the wind is at its highest on a particular plot of land. (siting.)

45% = offshore wind farms. (VERY expensive to build.)

Most sites built in the past few years produce 30 to 40% of their maximum capacity per calender year.

A turbine placed "ten feet further to the left" or "ten feet further to the right" can change the output of the turbine by thousands of kilowatt-hours over the life of the turbine. Therefore, hundreds of manhours and computer processing hours are spent on getting the most out of a site.

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hey amazingdrx. thousand-foot turbines? I'm all for it! The only thing keeping the turbines from becoming larger is the strength of the blades. (From what I understand. I'm not sure about it.)

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Chuck the Lucky. I agree 100%. People often seem to judge alternative energy sources as an all or nothing replacement for fossil fuels. Alternative energy will not meet 100% of our needs within the next few years, but it can produce much more than the few percent it produces today.

-----

Ender - I thought you could pretty well with advanced weather prediction such as this:
http://www.djc.com/news/en/11146933.html
can greatly increase the reliability of wind power. Also dispersed wind farms are unlikely all to have no wind at the same time.

I should have been more specific. You can't guarantee how much the wind will blow during the length of a several-year contract. Yes, the wind is VERY predictable for days ahead.

amazingdrx

I've got a novel idea for the blade problem Jeff. As with the fictional King Kong (he would be physically impossible), giants tend to have their weight exceed the strength of the materials they are made from.

I guess I better keep it under wraps until I can talk to a patent expert.

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