We know that you’ve heard of wind and solar power, but have you heard of poop power? At some farms in the US, cow manure is being mixed with food waste to form a smelly smoothie that gets dumped in something called a digester. Inside the digester, microorganisms break down the mixture of dung and food into a gas. The gas is then sent through a pipe to an engine that converts the gas to power and heat. Not only can such a system provide enough renewable energy to power the farm, but the excess power it produces can be sold back to the grid.