Here in California we pay between $.4 and $.5 and they are going to raise the prices again next year. It’s really, truly insane.
I've also thought that if one could figure out some of the power electronics a wrecked Prius engine just ticking over at idle would probably provide most of your off-peak power and charge batteries and then during peak times it could just ramp up a bit. I've never heard of a natural gas conversion though so it would be a long road I suspect.