How Do Solar Panels Work?

For the first half of 2023, renewable sources, including solar, wind, and hydro, produced 25% of America's electricity. But how do solar panels make electricity out of light? Can they be a viable replacement for fossil fuels at scale? In this article, we'll look at how solar power works and what it can—and can't—do.

How Do Solar Panels Generate Electricity?

The Earth's surface receives about a kilowatt of solar energy per square meter under optimal conditions, which means "at the equator, at solar noon." The best solar cells can wring out nearly half that light energy as electricity.

It happens like this: A photon from the sun strikes the solar panel's photoactive layer, which "knocks" an electron out the far side of the panel. This is possible because solar panels use semiconductors to transform light into electricity.

Silicon, like carbon, has a half-full ...