Intense summer sun can spike temperatures of solar panels, causing their electrical production to plummet.

Like humans, solar panels don’t work well when overheated. Now, researchers have found a way to make them “sweat”—allowing them to cool themselves and increase their power output.

It’s “a simple, elegant, and effective [way] to retrofit existing solar cell panels for an instant efficiency boost,” says Liangbing Hu, a materials scientist at the University of Maryland, College Park.

Today, more than 600 gigawatts of solar power capacity exists worldwide, providing 3% of global electricity demand. That capacity is expected to increase fivefold over the next decade. Most use silicon to convert sunlight to electricity. But typical silicon cells convert only 20% of the Sun’s energy that hits them into current. Much of the rest turns into heat, which can warm the panels by as much as 40°C. And with every degree of temperature above 25°C, the efficiency of the panel drops. In a field where engineers struggle for every 0.1% boost in power conversion efficiency, even a 1% gain would be an economic boon, says Jun Zhou, a materials scientist at Huazhong University of Science and Technology.

Decades ago, researchers showed that cooling solar panels with water can provide that benefit. Today, some companies even sell water-cooled systems. But those setups require abundant available water and storage tanks, pipes, and pumps. That’s of little use in arid regions and in developing countries with little infrastructure.

Continue reading… “New solar panels suck water from air to cool themselves down”