Non renewable energy resources are the fossil fuels (Coal, oil and natural gas) and nuclear fuels.  Power station (Fossil fuels)     Fossil fuels release a lot of heat energy when they are burned.    Fossil fuels are burned in power stations, the heat released is used to heat water. The steam       produced is used to drive turbines. The turbines then drive generators which produce electricity.    The Earth’s supply of fossil fuels (coal, oil and gas) and of nuclear fuels is limited.    It will take millions of years to replace the fossil fuels we have used.    Most of the energy used comes from non-renewable fuels, mainly from fossil fuels.  Power station (Nuclear Fuel: Uranium)    In a nuclear power station, the process of nuclear fission (unstable uranium splits into two)        releases thermal energy that is used to heat water. The steam produced is used to drive turbines.       The turbines then drive the generators which produce electricity.       Remember, nuclear fuel is not burned, it is used to heat water in a "heat exchanger".