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Comment by bob1029 | Hacker News Reader

> Thermal plants require energy to start up

It's not just about the power. System components cannot be brought to operating temperatures, speeds and pressures faster than mechanical tolerances allow. If a thermal plant is cold & dark, it can take days to ramp it to full production.

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That's true of some kinds of thermal generators, but not all. Simple cycle gas turbines can come up very quickly (think jet engines). Or your car's engine.

> Simple cycle gas turbines can come up very quickly

In some cases yes. Modern combined cycle plants can take as little as 30 minutes to ramp to full output. Older designs can take upward of 4-6 hours.

If you have steam as an indirection, that's when things take a really long time. Natural gas turbines are a more direct cycle.

Combined cycle turbines do have a steam component (that's where the word "combined" comes from). The waste heat from the combustion turbine front end is used to make steam in the back end.

Combined cycle turbines are not primarily powered by steam. It is a secondary consequence of their operation. This contrasts with nuclear and coal plants where steam is the prime mover.

That's what they said, though

The steam part of CC systems shows hours and hours aren't inherently needed to get a steam power plant in operation. For that matter, warships with steam propulsion show the same thing, I believe.

Can thermal stations be kept running without any laod?

Sure. But not cheaply. And ramping up the power still takes time.

This capability is called "Trip To House Load".

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