Energy exists freely in nature. Some of them exist infinitely (never run out, called RENEWABLE), the rest have finite amounts (they took millions of years to form, and will run out one day, called NON-RENEWABLE). Non-renewable energy is energy from fossil fuels (coal, crude oil, natural gas) and uranium.Fossil fuels are mainly made up of Carbon. It is believed that fossil fuels were formed over 300 million years ago, when the earth was a lot different in its landscape.It had swampy forests and very shallow seas.ir, water and land pollution are all consequences of using fossil fuels. In the pages that follow, we shall take a look at what each source of non-renewable energy is made of, and how they are used. Note that not all non-renewable energy comes from fossil fuels. There is also uranium, which is not a fossil fuel.