The news that Microsoft plans to fund the reopening of the undamaged reactor at Pennsylvania’s Three Mile Island nuclear plant spread almost as quickly as news about the nuclear accident at that same site in 1979. Microsoft’s decision was animated, as the Journal reported, by the “gargantuan amount of power needed for data centers for AI.” During the nuclear industry’s long winter following the 1979 accident, it would never have occurred to anyone that algorithms and not Congress would revive nuclear energy.

Three Mile Island’s city-scale power generator and massive concrete cooling towers now epitomize digital energy realities. But all the hullabaloo over the plant’s resurrection is about the kind of power that a single hyperscale data center uses. Hundreds more data centers are under construction or planned. Thousands more will be built. There aren’t enough nuclear reactors operating or planned to meet that kind of demand, even if the few retired ones are resurrected. How much electricity will digital innovations need?

The arrival of useful, affordable artificial intelligence is a wild card. It’s hard to predict how much AI will boost electric demand, since consumers and entrepreneurs are still sorting out where and how to use it.