For EnBW, the energy sources coal, gas and oil are an essential component of a reliable energy supply. In view of the rapid expansion of renewable energies, flexible coal-fired and gas-fired power plants play a central role in ensuring reliable performance in times of low regenerative supplies.
A coal-fired power plant uses steam to convert heat energy into electrical energy – hence the name “steam power plant”.
The combustion of coal produces hot flue gases in the boiler. These are used to generate steam. The steam flows through a turbine and transfers its energy to the turbine blades. This energy is converted into turning energy. The turbine shaft drives a generator that generates electricity.
In the condenser, the processed steam is cooled down to water, which is pumped back into the steam generator. The desired electrical energy is thus produced from chemically bound energy (coal) via thermal energy (steam) and mechanical energy (rotational energy).
Power plants generally generate electricity by burning fossil fuels. Plants that generate not only electricity but also heat (e.g. district heating) at the same time work according to the principle of combined heat and power generation and are also referred to as combined heat and power plants.
The heat is extracted as hot steam from the turbine. It is then transferred via heat exchangers to a distribution system that delivers the heat to private households (heating) and industrial plants (process heat). The simultaneous generation of electricity and heat makes better use of the primary energy used by the fuel and thus significantly increases the efficiency of CHP plants. In addition, pollutant emissions are reduced because the central district heating supply from the combined heat and power plant replaces a large number of decentralised individual furnaces.
EnBW operates most of its conventional plants with environmentally friendly co-generation of heat and power.