Cogeneration units are known for their high efficiency, as thanks to combined heat and power (CHP), they use 80 to 90 percent of the energy in the fuel. Their environmental impact level is even better if they are operated with biogas or sewage gas because then they are not only highly energy efficient, but also climate friendly. Another advantage in terms of sustainability is that if only waste materials are used for biogas cogeneration units, they do not represent competition for food cultivation.
They can also play a key role in ensuring a reliable power supply as part of the energy transition as small plants with outputs between 30 kilowatts (kW) and 3 megawatts (MW) can be installed locally and used to supply microgrids, making the construction of overhead lines unnecessary and the power grid more resilient and efficient. Since they can be regulated so well, cogeneration units are good backups for volatile energy sources such as wind or sun, and their flexible operation means they can contribute to load balancing and therefore increase the resilience of the power grids. In short, for companies with gas from agricultural waste – especially liquid manure – or sewage sludge, cogeneration units are the ideal solution for a decentralised energy supply based on renewable energies. A growing number of dairies, farmers, municipalities and operator communities are therefore relying on this concept, which has been in use for over 20 years and is based on tried-and-tested technology. As a result, in 2022, 50.2 terawatt hours (TWh) of electricity were generated from biomass in Germany alone.