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comment by WanderingEng
WanderingEng  ·  2905 days ago  ·  link  ·    ·  parent  ·  post: Coal is dead, because nobody wants to build coal-fired power plants.

Boilers are like 35% efficient. Coal is just the fuel. I know just enough to say almost but not quite the right thing. I think I'm thinking of the Carnot efficiency limit discussed on the Wikipedia Rankine cycle page.

    This gives a theoretical maximum Carnot efficiency for the steam turbine alone of about 63% compared with an actual overall thermal efficiency of up to 42% for a modern coal-fired power station.

Coal plants (really pretty much any utility scale plant) will assume a 40 year life with lifespan extensions beyond that. People would happy build coal-fired plants if they thought they would remain profitable for 40 years. But the regulatory uncertainty means there's a really good chance they won't be.