The heat sources of a thermal power plant are:
- Fossil fuels (coal, diesel and natural gas)
- Nuclear reactions of uranium atoms.
- Solar energy.
The first two are non-renewable energy sources. On the other hand, biomass and solar energy are considered renewable energy even though the former emits greenhouse gases and solar thermal power plants do not.
How Does a Conventional Thermal Power Plant Work?
A conventional thermal power plant is a thermoelectric plant that can use coal, oil or natural gas as fuel. They are the most widely used thermal power plants despite the environmental impact and the emission of carbon dioxide and other greenhouse gases that they produce.
The operation of the cycle of conventional thermoelectric plants is the same regardless of the way in which heat is obtained.
The typical thermal power plant is divided into several segments: a boiler, a turbine, an alternator, and a condenser.
In the boiler the fuel is burned to obtain thermal energy. With this energy a fluid is heated to obtain water vapor. Steam is used to drive a steam turbine in this way, the internal energy of the steam is converted into mechanical energy.
Finally, the steam turbine is connected to an alternator that transforms the energy into electricity. The resulting steam passes through a condenser to restart the cycle.
What Are Combined Cycle Power Plants?
Combined cycle thermal plants are thermoelectric plants that combine conventional cycle plants with a gas turbine. The combined use of gas and steam cycles improves energy efficiency and yields close to 55% are achieved.
The fuel for this type of plant is natural gas, diesel and even coal if it is prepared in a special way.
The main characteristic of the gas cycle is that there is no phase change of the fluid. The process is the following:
- Gas compression.
- Gas heating.
- Gas expansion in a gas turbine. In this case, the turbine is connected to an electric generator to produce electricity.
The gas that comes out of the gas turbine is still at a very high temperature so it is used to generate steam and activate a conventional cycle in parallel.
Can Thermal Power Plants Run on Solar Energy?
The concentration of all the solar energy at this point generates very high temperatures that are used to generate steam.
From here on, the operation is the same as in any conventional thermal power plant.
What Effects Do Thermal Power Plants Have on the Environment?
Currently, thermoelectric plants are obliged to control their emissions. This obligation is particularly relevant for large power plants where there is an important section to reduce pollutants.