What is non-renewable energy?

Non-renewable energy comes from sources that can't be replenished in a short period of time. We get most of our energy from nonrenewable energy sources, which include fossil fuels such as
oil,
natural gas,
coal and from
nuclear energy. Fossil fuels are thought to have been formed from the buried remains of plants and animals that lived millions of years ago.
Did you know that between 20 to 25 percent of the electricity generated in Pennsylvania comes from our five nuclear power plants?