“The drawback of conventional taxonomies is that they fail to adopt and define emerging technologies ... classification uses the non-renewable term for mostly brown energy such as coal, gas ...

A lot of our energy comes from non-renewable sources such as coal, oil and gas. These resources are made up from the remains of ancient animals and plants… …that ...

Renewable energy sources are plentiful and all around us. Fossil fuels - coal, oil and gas - on the other hand, are non-renewable resources that take hundreds of millions of years to form.