
The Solar Panel That Works at Night: How Thermoradiative Diodes Are Breaking the Limits of Solar Power
The panel on the rooftop of the Spilker Building at Stanford University looks like any other photovoltaic array. Its dark blue surface tilts toward the sky, absorbing sunlight during the day and converting it into electricity. But when the sun sets and the other panels in the test field go dark, this one keeps producing. Not much—a trickle, really, about 50 milliwatts per square meter—but the trickle is enough to power an LED or a small sensor. And it never stops. Through the night, through overcast days, through the dead of winter, the panel generates electricity from something that was long considered a waste product: the cold of space.







