5. Electric power stations that use non-renewable energy sources

Most of the electricity that we use comes from electric power stations that use non-renewable energy sources. There are two types: thermal power stations and nuclear power stations.

5.1 Thermal power stations that use fossil fuels.
Thermal power stations use fossil fuels to produce thermal energy. Then the thermal energy is converted to mechanical energy, in order to generate electricity.
Fossil fuels which is connected to the rotor of a generator. The generator produces electricity, which is transported by a network of high voltage power lines.

• Combined-cycle power stations.

Is generated in two systems. The first system burns natural gas with compressed air. This produces superhead gases, which turn a turbine to generate electricity.

The second system uses the hot gases from the first system and uses them to produce steam in a heat recovery boiler. Then the steam turns a turbine to generate more electricity. This makes combined-cycle stations more efficient that single-cycle stations.




5.2. Nuclear power stations.

• Advantages: are their productivity and profitability. They produce lots of electricity that can be sold a profit.
• Disadvantages: are the risks of nuclear accidents and the management and storage of radioactive waste.