[robocat]

Incorrect.

most of the cost of peaker plants is the capital cost. The fixed costs are high and spread over few hours (peaker) or even no hours at all (just providing ready capacity if required e.g. ready in case of faults with generators or transmission).

The variable costs (fuel) are normally quite irrelevant.

[ZeroGravitas]

Ireland already has the gas capacity built though. It provides about 50% of their power today, so they just need to phase it down and then out, not build it from scratch.

This is broadly true of most developed nations.

[badpun]

If the standby gas capacity is needed to cover a majority of country's needs a few times a year, can it really be phased down?