Comments on: Why Capacity Factor Matters to Energy Production

By: M. ELSHEIKH

M. ELSHEIKH — Tue, 20 Dec 2011 05:48:24 +0000

what I need to know is which type of the capcity we should use to calculate the capacity factor of a certain unit, we have different types of capacity :
-name plate(mentioned by manufacturer)
-actual( at 50c)
-ISO(@ 15c,1.013 bar and 60% RH)
-dependable(depend on inlet temp.)

By: anon

anon — Wed, 13 Apr 2011 14:23:14 +0000

You state that “The missing 26.3% is primarily due to equipment problems caused by the aging and lack of maintenance on the nation’s coal fired plants.” Does this mean that new coal plants operate at a similar capacity factor as nuclear plants? Can you please provide sources or supporting evidence? Thanks.

By: National Nuclear Science Week 2011: Get to Know Nuclear

National Nuclear Science Week 2011: Get to Know Nuclear — Mon, 24 Jan 2011 05:01:24 +0000

[...] average capacity factor of American nuclear power [...]

By: Energy Density and Waste Comparison of Energy Production

Energy Density and Waste Comparison of Energy Production — Fri, 18 Jun 2010 21:23:49 +0000

[...] to 292.875 MWh. I calculated the average output of a 1,000 MW rated natural gas and oil plant, with capacity factors of 11.4% and 13.4% respectively, to come up with the number of MWhs produced by each theoretical [...]

By: Jack Gamble

Jack Gamble — Fri, 21 May 2010 13:47:15 +0000

I would agree that natural gas and biomass could acheive a capacity factor similar to coal, but they don’t. It’s not because they aren’t needed, it’s because they’re just too expensive to operate. Expensive fuels is as much a cause of low CF as intermittent sources or equipment failures, if not more.

As I said in the post, I would expect the CF for natural gas has improved since 2007 because the price of natural gas has dropped with the financial collapse.

Nuclear can handle varying load, the fact that it can’t is a misconception. It’s just not perferable to run a reactor at 50% power because it’s so cheap to operate, why not shut down that expensive gas turbine instead? I don’t rate it at91.8%, this is an undisputible fact courtesy of the EIA.

By: anon

anon — Fri, 21 May 2010 06:17:47 +0000

You are mixing up two concepts here, the achievable capacity and the currently used capacity. Biomass and gas could provide as much capacity and reliability as a coal fired plant. It is just not called upon due to the varying load.
So you are not really mesuring potential with your numbers, but actual load.

Nuclear is actually bad because it can’t handle varying load – still you rate it at 91.8%..

By: Comparing Energy Costs of Nuclear, Coal, Gas, Wind and Solar

Comparing Energy Costs of Nuclear, Coal, Gas, Wind and Solar — Thu, 06 May 2010 13:27:04 +0000

[...] calculate the per kilowatt-hour (kWh) cost. This methodology controls for variable factors such as capacity factor and useful [...]

By: Avoiding Energy Sprawl

Avoiding Energy Sprawl — Tue, 27 Apr 2010 01:29:47 +0000

[...] provide for all of the electricity demand of the United States. Of course that number ignores the capacity factor of wind so you would need considerably more turbines spread throughout the country to compensate [...]

By: Jack Gamble

Jack Gamble — Sun, 18 Apr 2010 17:57:28 +0000

Mark,

Just to clarify, Capacity Factor is independent of thermal efficiency, which is what you’re describing. Thermal efficiency is a measure of electrical energy produced divided by thermal energy of burning the fuel.

Capacity factor has to do with what % of full power-24/7 does that source produce. Regardless of thermal efficiency, if a generator on runs at 50% of the plate value (even at 100% thermal efficiency, then the capacity factor is only 50%. If the generator runs at 100% power all day every day (even at 5% efficiency) then the capacity factor is still 100% even though much of the potential energy is wasted.

By: Mark

Mark — Thu, 15 Apr 2010 06:44:48 +0000

Hey Jack!

Thanks for the article. I just had something to point out: I think the capacity factor for combined cycle natural gas plants is actually 42%. The capacity factor for conventionally-fired natural gas plants is 11.4%.
(see: http://www.eia.doe.gov/cneaf/electricity/epa/epata6.html)

When you use the waste heat in a gas-steam turbine system to generate electricity (the combined-cycle approach), your efficiency rises to upwards of 60% and power generation suddenly becomes a lot cheaper. That’s why combined cycle plants have a capacity factor of 42%.

Centralized gas turbine combustion (see http://www.naturalgas.org/overview/uses_eletrical.asp) and gas-steam turbines make up nearly all of the electricity generation not attributable to combined cycle plants. They have a capacity factor of 11.4% because these technologies really aren’t intended for base load generation; they’re better suited for distributed generation during peak load hours, as you said.

Kind of splitting hairs, but just thought I’d provide the link. (An article about global electricity production is here http://www.eia.doe.gov/oiaf/ieo/electricity.html .)

Is it true that you can reprocess spent nuclear fuel indefinitely? I thought it could only be fed through a few times. Also, do you know if closed fuel cycles (reprocessing) is outlawed in the US or just not common practice?

-Mark