Comments on: Kilo-who’s-its and Mega-what’s-its: A Primer on Energy, Power and Capacity

By: Formosa

Formosa — Fri, 27 Jun 2008 12:48:51 +0000

I challenge you to study and discuss the actual operation of conventional power plants vs. wind turbines on our grid. As you pointed out to Even his flaw, your severe flaw is making the assumption that _base load_ conventional power plants are operated simply by turning a knob from 0% to 100%, and that knob is directly coupled to the amount of _fuel_ they consume.

You do clearly understand that a coal plant produces electricity by heating water, generating steam, and turning a series of turbines?

Please research this and tell Evhen and your readers how long (in days and hours) it takes to bring a coal plant up or down in operating temperature, and what really happens when the turbines are asked to produce more or less. You will quickly find the flaw in your “knob” analogy and Tom Gray of the American Wind Energy Association clearly knows this —

If you beleive that when wind goes online for a period of hours that a coal plant then turns down a knob which then reduces coal consumption you are operating under a flawed assumption.

You do realize that wind operators do not publish operating output figures? To a company they state this data is confidential. Ask Tom Gray about that one.

The real myth is that wind replaces conventional power plants. There’s not a single example of this anywhere in the world after 20 years of industrial wind.

By: Luke Weston

Luke Weston — Sat, 07 Jun 2008 10:13:03 +0000

Irrespective of what the exact, actual capacity factors are (20-25% for solar, 25-30% for wind, 80-90% for coal, and 80-100% for nuclear, as a general rough idea), the overall content and spirit of this post is very good, and a very useful thing in educating people about making meaningful comparisons of different energy systems. Great work!

By: Andrew

Andrew — Fri, 18 Apr 2008 10:56:48 +0000

A 33% capacity factor is a vast over-estimate for all but the most optimal locations and extremely low downtimes for new turbines that don’t yet require much upkeep.

Actual constructed wind farms are closer to 16%.

http://www.german-renewable-energy.com/Renewables/Navigation/Englisch/wind-power.html

That’s from Germany, a country which is staunchly pro-wind, not a nuclear lobby or some other suspect source.

US Capacity factor is perhaps 28% as claimed by the US wind industry lobby:

http://www.awea.org/faq/wwt_statistics.html#How%20much%20wind%20generating%20capacity%20currently%20exists%20in%20the%20U.S.%20How%20much%20will%20be%20added%20over%20the%20next%20several%20years

But I find that figure suspect and likely high. Also that will decrease as the more choice locations are taken. (NM, they removed it, probably because it’s both embarrassingly low and a inaccurate over estimate). Also this doesn’t factor in increased transmission losses due to the distant and distributed nature of wind power.

Either way, a 33% capacity factor is far from typical.

Please see my post on the other thread which addresses the intermittent problem of wind power, wind power can be used to offset some fossil fuel use, but it can’t do much over 20%.