we know how much offshore wind power from an existing plant will cost to produce in 20 years' tim, but we have no idea whatsoever what power from a gas-fired power plant will cost then. That certainty has value.

In fact perhaps the prime objective of public policy (apart from sustainability and greenhouse gas emissions reduction) is to improve the visibility, predictability and volatility of future economic and social costs of energy - a bit like an insurance policy against unpredictable future costs. What's wrong with the state buying insurance against future price volatility?

Index of Frank's Diaries