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.
So, who’s right?
Anti-nuclear environmentalists are right that Diablo Canyon will be cheaper to shut down rather than keep open in the long term. But pro-nuclear environmentalists are right that it’s political choices that will make the plant expensive.
Let me explain:
Right now, Diablo Canyon power is cheap, but that’s likely to change
Lucas Davis, an energy economist at University of California at Berkeley, told me that because Californians have already paid for Diablo Canyons construction, the cost of producing electricity is probably around $27 per megawatt hour — the cost of salaries, fuel, waste management, and all the other operating expenses. That’s pretty cheap! Pro-Diablo people like to quote some version of that price.
However, costs will rise if it doesn’t shut down in 2024 as planned. A California regulatory committee has required the plant to build a multi-billion dollar water-recycling system, so that it doesn’t kill fish eggs when it draws water out of the ocean. Building the cooling towers to reuse the water would drive up prices. Anti-Diablo people like to quote some version of a price (like $70 MWh) that includes this.
The other economic bullet aimed at Diablo Canyon is renewable energy. Californians aren’t using any more electricity each year, and the state keeps subsidizing more renewable power. As any economics student knows, adding supply without expanding demand leads to lower prices. That’s making it harder for older power plants to compete.
Are renewables cheaper?
Everyone also brings their own numbers on renewables to say that existing nuclear is more — or less — expensive.