Power-hungry humans

Vaclav Smil and Chris Turner on the millennia-old story of energy

Just before Christmas, I found myself at a snowbound cabin in the woods about three hours north of Toronto. The cabin was off the electrical grid. It featured a wood stove for heat, solar panels for light, and a backup generator for emergencies. Every morning, my husband knelt before the wood stove, worshipfully coaxing its embers back to life and tending to the fire as the day wore on with split logs from the stack kept outside by the door. Every morning, I dashed out in my tall rubber boots and parka to sweep the night’s blanket of snow off the solar panels, waking them so they could store the sun’s rays for the day to come.

It wasn’t just that we were patrolling our energy use. (Did that light really need to be on? Couldn’t I wear one more sweater rather than put another log on the fire?) And it wasn’t just that we were acutely conscious of where the energy came from—the sun, the woods around us. It was...