[ta1243]

So I have a grid with Gas and Renewables connected.

100% Gas will use 100TWh of gas to generate power

50% renewable will use 50TWh of gas to generate power

[nothercastle]

You missed the fact that the mix shifted. Coal and nuclear are too expensive where solar is available so you go from: 35% coal 30% nuclear 35% gas

You go to 60% solar 40% gas.

Obviously the numbers are made up but that’s the point I’m trying to make.

[ta1243]

Or you go to 70% solar and 30% gas?

If your example you've reduced generation from fossil fuels from 70% to 40% so still a win.

I assume you're still going on about nuclear. The problem with nuclear is that it doesn't make financial sense even if it can run at 100% of capacity for 100% of the time, it certainly can't cope with variable load - you can't scale nuclear to provide your peak amount, so you need to be able to top up with gas or battery, just like renewables need top up