How is energy generated from natural gas

In conventional power plants, the energy source - mostly coal or natural gas - is used to generate electricity or heat. Fossil-fired power plants are still required for a reliable electricity supply. With a view to the rapid expansion of renewable energies, they play a central role in a secure supply of electrical energy. They are still essential for a stable power grid and can be used regardless of the weather.

functionality

Air that is sucked in is compressed in the combustion chamber of a gas turbine and then mixed with a fuel. This mixture is ignited and burned. A gas with a temperature of up to 1,500 degrees is created, a connected turbine part converts this thermal energy into kinetic energy - heat becomes movement. A generator uses it to generate electrical energy. Various liquid or gaseous fuels are used as fuels, primarily natural gas.

Gas turbine power plants can achieve full output within a few minutes, which is why they are particularly suitable for covering short-term peak loads. On the way to a power supply that is predominantly based on renewable energies, such flexible and quickly deployable power plants will play an important role. Because they help to close the gap that arises between the demand for electricity on the one hand and the strongly fluctuating generation from renewable energies on the other - for example when there is no wind and at the same time weak solar radiation.

Example of a gas turbine power plant

In power station 1 of the Stuttgart-Gaisburg thermal power station, a gas turbine with an output of 60 megawatts helps cover peak loads. With natural gas as fuel, the gas turbine reaches its full output after just five minutes with a quick start.

It also secures the power supply in the event of failure of other systems. In addition, a diesel generator ensures that a so-called black start can be carried out in an emergency: If the power grid should ever collapse over a large area, the turbine can be started up by the power plant employees - without any external energy consumption. In this way, if the worst comes to the worst, the power supply can be rebuilt and the power grid stabilized bit by bit.

Combined gas and steam power plants (combined cycle power plants)

The investment outlay for pure gas turbine power plants is relatively low compared to other types of power plant: The costs per kilowatt of installed capacity are considered here. The disadvantage of this type of power plant, however, is its rather low efficiency, which is below 40 percent. If, on the other hand, the waste heat generated during combustion is also used to generate electricity, the efficiency increases to up to 60 percent. These power plants are known as combined cycle power plants (combined cycle power plants): The fuel used is used particularly efficiently.

Combined cycle power plants are therefore used in the medium load and the base load. Turbines with an output of 100 kilowatts to 40 megawatts are often installed in combined cycle plants. They have very short start times of just a few minutes and can be used particularly flexibly. Larger turbines with an output of 50 megawatts to 340 megawatts, on the other hand, run continuously and are therefore more likely to be installed in large coal-fired power plants.

Gas turbines can achieve full performance within a short period of time: Large quantities of air drawn in are compressed in the compressor and flow into the combustion chamber of the gas turbine. There, natural gas is burned with the compressed air. The hot flue gas flows onto the turbine at a high temperature and drives it.

In the Rheinhafen steam power plant in Karlsruhe, coal block 4 was converted into a modern gas and steam block. Here a gas turbine with a waste heat boiler has replaced the old boiler system. The steam turbine was still used, before that it was completely overhauled technically and mechanically. The area of ‚Äč‚Äčapplication of this power plant is primarily in the generation of peak load electricity.

To the Rheinhafen steam power plant in Karlsruhe