While oil gets the attention, America uses just 15% more of it today than when the first modern energy crisis hit in October 1973.

But electricity use is up 115% since then, thanks to all those plasma screens, iPhones, computers and data centers. And all economic forecasts see substantial growth in demand for electricity—think just of the coming electric cars—yet lots of problems in meeting it.

Right now the nation has 760 gigawatts of power plants to meet current consumption, with another 154 in reserve capacity to maintain grid reliability. But in fact only 10 gigs is truly excess capacity. The other 144 is utterly essential to keep lights on when unexpected demand arises from heat waves, outages or maintenance downtime. That reserve will begin to shrink quickly. NERC estimates that over the next decade 135 gigawatts of new capacity will be needed to meet the growth in consumption. But right now plants producing a total of 57 gigawatts are planned.

Ninety percent of electric power is fueled by nonrenewable coal, natural gas or nuclear power. Renewable sources will not cover the growth in demand. While wind is gaining ground (and now supplies 1% of power), hydro's share (7%) is shrinking as dams are dismantled. Solar, at 0.01%, is an inconsequential contributor.