Nov 18Liked by Brian Potter

That was a marvellously lucid explanation of the history of the gas turbine, pitched just right for the interested lay-person. Thank you!

Brian: you, Ed Conway with "Material World", and the Works In Progress crew (and perhaps Bent Flyvbjerg too,) between you all, seem to be recapitulating and expanding on the work of Vaclav Smil, in a far more readable way. I have a copy of his "Energy in Nature and Society", and between the typos and the lack of firm editing for readability, it's a bit of a slog.

Don't take that as belittling what you are doing: it's vitally important to clearly explain the facts of life and how we got to where we are today. Smil has done that for a few academically-oriented people; you all are doing it for everyone else. Thanks again.

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Nov 21Liked by Brian Potter

Excellent article and as another commenter noted, perfectly pitched for the knowledgeable layman.

In 1982 as Engineering Manager of Alcon's Puerto Rico plant I negotiated and signed the contract with O'Brian Energy. O'brien was to build, own and operate a cogeneration plant on our site to. Provide electricity and chilled water.

This led to a kerfuffle with the PR Power Authority trying to block it.

That eventually led to FERC ruling in favor of alcon/o'brien and mandating utilities nationwide to permit 3rd party owned cogeneration

You are welcome.

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One point missed in your otherwise excellent article is that the start-up time for CCGT keeps getting lower. It is now less than 30 minutes, versus many hours in the past. The start-up time is critical because our grid needs an energy source that can load balance for intermittent renewables. Previously, we could only do this with Simple Cycle gas plants (essentially a jet engine), which are far less energy-efficient than CCGT (40% vs 60+%).

This makes expanding CCGT a no-brainer because it can run as a base load (to substitute for coal) and peaking (as a complement to solar/wind). And it is much cheaper than nuclear or hydro.

Renewables need natural gas to load balance, so Greens should be in favor of its expanded use.

And best of all, it does not require government subsidies or mandates. The economics are justification in itself.

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Another excellent post! I love the shift to natural gas.

I believe that the combination of the Shale gas (discussed in your previous post) and Combined Cycle Gas Turbines is one of the most important energy revolutions of the 20th/21st century. With Shale Gas and CCGT, I believe that we have a far better alternative to renewables or coal. Expansion of both would be good for the economy and good for the environment.

As I wrote in my book "Promoting Progress", the US could replace all existing coal plants with CCGT for less than $124 billion. This is about a quarter of the cost of Biden's Inflation Reduction Act. For each plant, this would be a 67% reduction of carbon emissions and a virtual elimination of air pollution. This is far more rapid decline than renewables can achieve, because they are typically in addition to fossil fuels rather than instead of fossil fuels. Plus it would lead to more affordable electricity.


I go into more detail on why we should support expansion of natural gas on my "From Poverty to Progress" YouTube channel:


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one peeve about an excellent article. Perhaps a bit pedantic.

You say that it is unfortunate that gas plants are carbon emitting. To the extent that they are, I agree it is unfortunate and that carbon emissions are pollution.

But carbon emissions are not really the alleged problem, are they? I think what you really mean is carbon DIOXIDE emissions, don't you?

I think there are two reasons people say carbon emissions when they mean CO2 emissions

Many are ignorant and honestly don't know the difference between C and CO2. Obviously you are not one of them.

I think the real reason is propaganda. It is easier to get people worked up about carbon, a visible, dirty (coal, graphite, soot) solid than it is to get them worked up about CO2. CO2 is pretty friendly. A harmless odorless gas with a lot of beneficial uses. Fire extinguishing, beer foam, risen donuts and so on.

I've been reading you for a while and have never noticed you being political so I don't really think that you are trying to propagandize us readers on purpose. I suspect that it is just sloppiness falling into the common usage on your part. I really wish you, and everyone else that knows better would stop it. If you mean CO2, say CO2 please.

On the other hand, if you meant carbon, in the opening to the article. Apologies and please ignore the above.

And while we are on the subject of propaganda, I wonder how often the fraction of various gases making up air are expressed as PPM. Other than in the classroom.

I have seldom seen CO2 expressed as anything other than PPM. I can probably count on 1 hand with fingers to spare, the number of times in the past 60 years that I have seen O2, N2 and other gases expressed as anything other than percentages, 21 & 78 respectively.

I think that this is purposeful propaganda. 400PPM seems like a scary number until you realize that 1) it is 0.04% and 2) for comparison N2 is 780,000ppm.

Nothing to do with anything you wrote here or elsewhere that I recall. Just another peeve that I wanted to get off my chest.

I always find your articles fascinating and well done. Even when they are on topics I normally have no interest in.

Sort of like John McPhee does for rocks and Henry Petrosky did for bridge engineering.

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Also worth mentioning, but recuperated closed Brayton cycle systems heated by a nuclear fission reactor are being investigated by NASA for producing large amounts of energy (40kW+) for space applications such as Moon and Mars bases, in-situ resource utilization (making rocket propellant on the moon or Mars so you don't have to bring it) as well as nuclear electric propulsion vehicles.

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Excellent post. To bad we can’t compare the progress of gas turbines vs solar without government involvement. My guess is that gas turbine technology would have advanced much quicker than solar if the government had subsidized neither. Do you have any data on the amount of subsidies going to each? My guess is solar subsidies far exceed those for gas turbines.

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Very interesting. On the caption above "But we can overcome this problem by raising the operating temperature of our turbine, which lets us make use of higher pressure ratios even with efficiency losses in our components." the text appears to not make sense though:

"At some point raising, the pressure ratio will decrease thermal efficiency"

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