There’s a political economy implication too. Renewables are getting more politically and culturally influential by the day. Warren Buffett, Citigroup, Deutsche Bank, the World Bank.. The wind PTC survived in the US Congress last December; the German solar FITS have just survived an attempt by Minister Altmeier to roll them back.

“Always on” generation like (already built and paid for) coal and nuclear plants have low production costs but they must sell at an overall profit. As other technologies such as wind or natural gas take away some of their hours, or force them to sell at a loss, the price that they have to earn during other hours rises. And that can force them to fail. A quarter of existing US reactors are in financial danger.

Natural gas is probably the best protected. NG plants have very low overnight costs and come on line quite rapidly. That means that they don’t have the sort of interest burden that new coal or nuclear would have. Most of their expense is fuel and since they can shut down during those time blocks in which they can’t sell at a profit, they can avoid the hurt that non-dispatchable generation encounters.