Bill McKibben writes:

Something approaching a miracle has been taking place in California this spring. Beginning in early March, for some portion of almost every day, a combination of solar, wind, geothermal, and hydropower has been producing more than a hundred per cent of the state’s demand for electricity. Some afternoons, solar panels alone have produced more power than the state uses. And, at night, large utility-scale batteries that have been installed during the past few years are often the single largest source of supply to the grid—sending the excess power stored up during the afternoon back out to consumers across the state. It’s taken years of construction—and solid political leadership in Sacramento—to slowly build this wave, but all of a sudden it’s cresting into view. California has the fifth-largest economy in the world and, in the course of a few months, the state has proved that it’s possible to run a thriving modern economy on clean energy.

A good place to view this feat is from Mark Jacobson’s home—a light-filled two-story modernist house that he shares with his family at the end of a classic suburban cul-de-sac on the edge of the campus of Stanford University, where he is a professor of civil and environmental engineering. In part, that’s because the house is an energy-efficient showpiece; its solar panels produce more than enough energy to cover what he uses, though it is still tied to the grid. In the garage, there are two Teslas (including a 2009 Roadster with a license plate that reads “GHG Free”) and a pair of the company’s Powerwall batteries. The first place Jacobson shows you on a tour is the mechanical room, where an air exchanger recovers ninety-seven per cent of the heat from the stale air that it pushes out of the house. Next up is the kitchen, where an induction cooktop cuts energy use by sixty per cent compared with gas, even as it boils water twice as fast. He also showed me an app on his phone that monitors his usage of the power generated by solar panels on his roof every few seconds. “Yesterday, seventeen per cent of the generation from my rooftop went into the batteries in the garage,” he said. “I used eight per cent of it at home, and I sold seventy-nine per cent to the grid.”

But the real reason to go see Jacobson is that he said this transition could and would happen. Beginning with an article he co-wrote for Scientific American, in 2009, he’s been making the case for a-hundred-per-cent renewable energy. It’s not been easy—after he won a prize, from the National Academy of Sciences, for a 2015 paper laying out the vision, twenty-one energy researchers wrote an analysis for the academy’s magazine that accuses him of modelling errors and of making “implausible and inadequately supported assumptions.” So Jacobson can be excused for crowing a bit on social media this spring, if you define crowing as posting almost daily graphs of the renewable-energy surge. [Continue reading…]