GAME CHANGER? MIT invents $4 solar desalination device.

The device worked for a week straight with no signs of salt accumulation, but we still don’t know exactly how long it could operate.

But the best news is that it would cost just $4 to build a solar desalination device large enough to meet the drinking water needs of a family of four, according to the MIT team. If it does prove durable, it could be a relatively cheap way to get freshwater to people in need of it.

“I think a real opportunity is the developing world,” Wang said.

Or in the de-developing parts of the world, like California.