5)ELECTRIC POWER STATIONS THAT USE NON-RENEWABLE ENERGY SOURCES

Most of electricity that we use comes from electric power station that use non-renawable energy sources. There are two types: Thermal power stations and nuclear power station.
THERMAL POWER STATION THAT USE FOSSIL FUELS
Thermal power stations use fossil fuels to produce thermal energy. Then the termal energy is converted to mechanical energy, in order to generate electricity.

Fossils fuels, are used to heat water in a boiler . Steam from the boiler turns a turbine, which is connected to the rotor of a generator. The generator produces electricity, which is transported by a network of high voltage power lines. After that, the steam goes to a condenser, where it cools and become liquid water again. Finally, the water is pumped back to the boiler.
Combined-cycle power station
In combined-cycle or cogeneration power stations, electricity is generated in two systems. The first system burns natural gases with compressed air. This produces superheated gases, which turn a turbine to generate electricity.
The second system use 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 make combines combine-cycle stations more efficient that single-cycle stations.
NUCLEAR POWER STATION
A nuclear power station is a thermal power station that uses a nuclear reactor to produce heat. The reactor uses radioactive material us fuel. The most commonly used materials are isotopes of uranium.

The main advantages of nuclear power stations are their productivity and profitability.They produce lost of electricity that can be sold at a profit.
The main disadvantages of nuclear power stations are the risks of nuclear accidents and the management and storage  of radioactive waste.