Energy security

Is nuclear power really that expensive?

There are dozens of dimensions in the arguments for and against nuclear energy as a source of clean electricity. But there’s one aspect that trumps all the rest: cost.

We don’t have to wade into the fights over safety or waste disposal if we can just compare the price of nuclear to the price of renewables. Nuclear averages between $112 and $183 per megawatt hour; utility-scale solar and wind ranges from $30 to $60 per MWh. Nuclear simply isn’t worth the money, right? Not so fast. Those numbers include the cost of building a new plant, which is really what makes nuclear expensive. What if we’re talking about existing nuclear, instead?

I’ve never been able to figure out the price of existing nuclear generation, because smart people I respect use wildly different numbers. So I set out to discover what was going on. As I asked around about this, I focused on one power plant as a case study: Diablo Canyon, which provides 9 percent of California’s power and has been slated for closure in 2024. The anti-Diablo crowd says it would be cheaper to close it down and spend the money we save on wind and solar. Pro-Diablo enviros say that the plant is cheap since it’s already built.