In Parts 2 & 3, I’ve complained about Richard S. Courtney’s awful descriptions of the current state of the bulk power system. By laying out a phony scenario, Courtney can then appear to show that wind energy doesn’t reduced CO2 emissions. Here in Part 4 I’ll show some data from one of my favorite power generators that, like what I showed in Parts 2 & 3, completely contradicts Courtney’s claims.
For most fossil-fuel burning electricity generation stations in the US, the EPA publishes load, fuel use, and emissions data. I’ve taken the time to download the data for 2007 & filter it down to the data for a unit known as Big Allis, AKA Ravenswood 3, or Ravenswood 30. Big Allis is a 1000MW steam plant that primarily burns natural gas that was built in the late 60s. Big Allis is a huge, old plant that has been operating for about 40 years: not exactly new technology.
Courtney claimed, “only small variation to the output of each power station is possible.”
This plot shows the time series of output from Big Allis for early 2007.
Does that look like “small variation” to you? I didn’t think so.
Based on the chart, I think we can definitely, albeit qualitatively, say that at least some steam plants are capable of very large variations in output.
Courtney also wrote:
But operating a power station at less than its optimum output severely reduces its efficiency so it has little reduction to its fuel consumption and emissions although it supplies less electricity.
The following 2 graphs attack two claims made here, first that efficiency is “severely reduce[d]” from
the optimum level. Clearly you have to get pretty far away, and well beyond a “small variation” from the optimum level before efficiency is severely reduced. Moreover, the change in fuel use with respect to output is something much greater than a “little reduction.”
The above graph shows the efficiency of Big Allis versus its operating level. Here efficiency is measured in ‘heat rate’, which is the ratio of fuel burned (measured here in MMBTU) to the amount of electricity generated (here in MW). Heat rate can be thought of the amount of fuel that must be burned in order to generate 1MW of electricity.
The 2nd graph shows fuel burn rate per hour at various operating levels. Clearly even when the efficiency of Big Allis is seriously degraded at lower operating levels, it is using much less fuel, and therefore releasing much less carbon, than it is at its optimum operating level.
Only a true idiot could see this and claim that backing down Big Allis “has little reduction to its fuel consumption and emissions”
