It's a sight that would bring joy to anyone who has ever paid an electric bill: that little wheel on the meter outside your home literally spinning backward, signaling a reduction in your payment and the distribution of excess electricity to your neighbors.
Yes, that actually happens at a few hundred thousand homes across the United States that have rooftop solar panels and are part of an arrangement known as "net energy metering."
"Every time people install a solar system, it means the need for more power distribution is reduced and the need for more energy generation (by utility companies) is reduced," said Ed Fenster, co-founder of Sunrun, a California company that installs rooftop solar systems.