Hundreds of scientists have been looking for solutions to our clean energy issue for decades, but could the answer have been hanging out in the world’s deserts all along?

We have some great options with wind, solar, and hydroelectric power, but experts are finding that storage capacity is a big issue. Battery technology has become the new – and biggest – hurdle to solving the world’s clean energy needs.

People have been throwing out wild ideas, like CO₂ bladders and giant weights that store kinetic energy until they’re dropped, but nothing has seemed realistic or easy to test.

At least not until now.

Sand stores massive amounts of energy as heat, and it can hold the excess created by wind and solar, dispersing it in times of need.

In fact, a large sand battery could store 8 megawatt hours of energy and discharge 200 kilowatts of power, both of which are huge amounts.

It could also store this energy for months on end with very little effort, says Polar Night Energy in a statement.

“Its main purpose is to work as a high-power and high-capacity reservoir for excess wind and solar energy. The energy is stored as heat, which can be used to heat homes, or to provide hot steam and high temperature process heat to industries that are often fossil-fuel dependent.”

Sand has a high boiling point, which means it can store more energy than water and so is really limited only by construction materials for the battery.

Polar Night is testing a large sand battery in Kankaanpää, a town in western Finland. There, it helps heat homes and also a local swimming pool.

It’s 23 feet tall and contains 110 tons of sand. When the energy inside is needed, air flows through pipes that set close to the sand. They get heated, then provide heating elsewhere or heat water into steam to power things like a turbine.

It is most efficient if if doesn’t have to convert heat into electricity, but it can if needed.

New and innovative types of batteries are desperately needed, and this cheap and available solution might be the best option out there right now.