The lignite power plants
Lausitz Energie Kraftwerke AG operates the Lusatian lignite-fired power plants Jänschwalde, Schwarze Pumpe and Boxberg. We are also the operator of the Lippendorf lignite-fired power plant near Leipzig and the owner of one of the two units. The supply of lignite fuel is ensured by the nearby opencast mines. In purely mathematical terms, the electricity generated by our power plants is sufficient to reliably supply more than 14 million households.
In addition to electricity, we also generate about three billion kilowatt hours district heat annually to supply thousands of households and municipal facilities such as hospitals, schools and offices. The supply takes place in close vicinity to our sites for example in Leipzig and the Lusatian towns of Cottbus, Spremberg, Weißwasser and Hoyerswerda. Our third product is process steam available for industrial customers.
|Power plant||Installed capacity||Electricity produced 2019|
|Jänschwalde||3,000 megawatts||15.4 billion kWh|
|Schwarze Pumpe||1,600 megawatts||9.8 billion kWh|
|Boxberg||2,575 megawatts||17.4 billion kWh|
|Lippendorf (Block R)||920 megawatts||6.8 billion kWh|
How does a lignite power plant work?
The lignite is stored intermediately in coal bunkers on the power plant site. From there it is transported with conveyors inside the plant. It is then crushed, dried and milled to dust. This is blown into the combustion chamber of the boiler. Here the lignite dust is burnt and heats water in the pipe system to produce large quantities of steam.
The high-pressure steam is then guided on to the impellers of the steam turbine which forces the turbine shaft into a rotary motion. In the turbine there are high pressure, medium pressure and low-pressure stages. These are designed in such a manner that the energy of the steam, that diminishes on the way through the turbine, can be used optimally
On the other end of the turbine shaft a generator converts energy of the rotary motion into electrical energy. This happens in a similar way to a dynamo on a bicycle. After transformation to 380 kilovolt, the electrical energy is transmitted via overhead lines to transformer stations and from there fed into the extra-high voltage grid. The steam is cooled down to condensate and reused for steam generation in the boiler via intermediate stages.
|Power plant boiler |
up to 1,000 °C
|Turbine and generator |
50 rotations per second
frequency of the electricity grid
|Several cleaning steps |
to reduce emissions
380 kilovolts extra high voltage
Lignite and the Energy Transition
The German energy supply is undergoing a fundamental change from conventional generation to the use of renewable sources – the Energy Transition (Energiewende). By 2022, the phase-out of nuclear energy is to be completed. The last coal-fired power plant is to be disconnected from the grid by the end of 2038 at the latest. Until then, our lignite-fired power plants will remain a stabilising factor for Germany's energy supply. Firstly, they are reliably available around the clock. On the other hand, they are highly flexible and support the system integration of solar and wind energy.
The amount of energy fed into the power grid must at all times correspond to the amount of energy withdrawn from the grid. This principle is essential to ensure that the electricity flows reliably. Electricity from renewable sources has priority in the grid. The production of the lignite-fired power plants is adjusted to the electricity demand of the consumers and the currently available electricity generation from renewables.
If a high volume of wind and solar power meets a low demand, our power plant park can reduce its production to 25 percent of the installed capacity. If wind or sunshine decreases, our plants can quickly increase their output. How far we can reduce the output of our power plants depends on external conditions such as temperature and district heating requirements. System services that we provide for the electricity grid operator must also be ensured.
The amount of electricity being produced out of renewable sources is increasing. But currently there is insufficient grid capacity to transport the electricity. Furthermore, large scale economical storage possibilities for electricity have still to be developed. That is why we are also involved in this field of technology. We are building and operating a battery storage facility at the Schwarze Pumpe power plant that is unique in Europe as regards its size and constellation – the BigBattery Lausitz.
Carbon dioxide emissions from lignite-fired power plants
Every combustion process produces carbon dioxide (CO2). CO2 contributes to the natural greenhouse effect in the earth's atmosphere. In order to limit an increase in this greenhouse effect and thus to limit global warming, man-made CO2 emissions are to be drastically reduced worldwide. For every tonne of CO2 emitted by our power plants, we are obliged by European and national regulations to procure a CO2 emission allowance. The European emissions trading system effectively limits the emission of greenhouse gases in the sectors involved.
LEAG, including its predecessor companies, has reduced its CO2 emissions by around 46 percent since 1990. This means that we have already exceeded the Federal Government's target of reducing CO2 emissions in Germany by 40 percent by 2020 against 1990 levels for our power plant park for quite some time. In addition to billions invested in efficient technology, this reduction was also attributable to the decommissioning of numerous eastern German power plants and industrial facilities after reunification.
Reduction of further emissions
The combustion of lignite as well as other fossil fuels produces flue gas. It is cleansed in our power plants and released together with steam via the cooling towers. Strict emission limits apply to power plant operation. They are expressed as concentrations in milligrams per cubic meter of flue gas. The emission limits are made mandatory by the permits issued in accordance with the German Federal Immission Control Act (BImSchG). We are obliged to continuously monitor compliance and report to the environmental authorities concerned.
The combination of a large number of technical measures ensures that emissions from power plants have been significantly reduced in recent decades. These include low-nitrogen oxide combustion, flue gas dedusting and flue gas desulphurisation.