(KXAN) — From sun to water to poop, renewable energy comes in a variety of forms.

David Yeomans, the chief meteorologist at Nexstar’s KXAN in Austin, explores renewable energy sources and why switching to them is so essential — including how, eventually, animal poop could help us use fewer resources.

You may be wondering: What is renewable energy and why are some energy sources renewable and some aren’t? As Yeomans explains in the video above, fuels like coal, natural gas and petroleum will eventually run out. Otherwise known as fossil fuels, these materials are drilled out from the Earth and are made up of the buried remains of ancient plants and animals.

But waste from animals is in never-ending supply. And it’s already being used for fuel.

As explained by the Texas A&M University AgriLife Extension, animal waste has many properties that make it amenable to power production, though some drawbacks also exist. When manure is used to make energy, the product is called biogas.

According to A&M’s Texas Animal Manure Management Issues page, biogas could eventually be produced on smaller scales and more immediately. For instance, farms or other animal facilities could recycle waste on-site and in real-time.