[tialaramex]

> Gas plants may still be running at a loss for whatever reason

My assumption, given how the UK numbers look when there are negative prices but still a little bit of gas running, is that shut down/ start up for a CCGT is so undesirable (expensive maybe?) that a 100MW plant which can say throttle to 5MW would rather pay to give you 5MW of electricity for the next half hour than switch off the plant and provide nothing then need to start it back up in a few hours.

I don't know what "throttling" looks like for this equipment. It seems implausible that these units have no ability to control their fuel usage/ power output at all, just binary on or off, but on the other hand presumably in practice it's far from infinitely variable.

[Panzer04]

I imagine it's just be keeping the equipment warm and moving, especially for something like a steam turbine. Partial output sounds like a reasonable guess to me.

[raphaelj]

That might be part of the answer.

But IIRC, in Belgium at least, these plants are also remunerated on "secondary" markets for non-productive tasks. These secondary markets are mostly for grid balancing.