Depends on the type of capacity. I gather that peaking power is typically provided by gas combustion turbines (https://en.wikipedia.org/wiki/Gas_turbine#Indust

Depends on the type of capacity. I gather that peaking power is typically provided by gas combustion turbines (https://en.wikipedia.org/wiki/Gas_turbine#Industrial_gas_turbines_for_power_generation https://en.wikipedia.org/wiki/Gas_turbine#Industrial_gas_tur...), which have much lower capital costs and much higher operating costs (including maintenance). But if you need more baseline, then, yeah, you're going to be spending a lot of money, although I'd expect modern gas powered baseline plants to be relatively cheap (don't ask about nuclear, and fuel handling is much easier than coal, plus coal is nasty dirty stuff that needs exhaust cleaning, and disposal of ash).