> it has to increase the cost of energy because you have to pay for renewables and pay for the battery operators to do nothing and pay for the gas operators to do nothing.

No, it doesn't have to increase the cost.

If you have a town powered by gas, the cost of maintaining and staffing the gas plant is locked in.

But most of the cost of that gas plant is the fuel.

If the total cost per kWh of a solar or solar+battery installation is lower than the fuel cost of the gas plant, then you build it. It saves you money even though you're paying the gas operators to do nothing part of the time.

If it's not cheaper than fuel, you don't build it. No harm no foul.

Follow that strategy and you'll end up with lots of renewables without wasting a penny.

Though honestly some idle gas plants don't cost that much. How many kilowatts do you need? 4? Okay, the fixed costs for 4 kilowatts of combined cycle gas power are $50 per year. That's all it takes to have backup production for the entire grid, even with no base load plants anywhere.