I am a blithering idiot. I cannot imagine how I managed to miss the obvious until yesterday. I’ve always though in terms of a single equation (with differing coefficients) to handle all the energy resources. The obvious solution is to model non renewables with a gaussian curve and renewables with an exponential curve. Here are the equations:

Nonrenewables: Supply(price) = a * exp(-((price - b)**2) / c)

Renewables: Supply(price) = (a * exp(price * b)) - c

Here’s what this yields when I use appropriate coefficients for the different energy sources:

All in all, this looks pretty good. Why didn’t I think of this before?