Continuous generation of electricity and heat
The biogas thus produced is generally utilised in combined heat and power (CHP) units for generating electricity and heat. Continuous operation of the CHP is ensured by filling and operating several fermenters at staggered time intervals. The electricity generated is fed into the electrical grid and is remunerated or sold on, subject to the national feed-in tariffs.
Only a small proportion of the excess heat produced is required for operating the plant. The majority of the heat energy generated is utilised externally; for example, it may be fed into a local or district heating grid or used for drying materials.
Generation of biomethane
Alternatively to power generation, the produced biogas can be processed into biomethane. This can then be fed into the natural gas grid or used as vehicle fuel (compressed natural gas). Thereby the generated energy can be stored and used in a wider market.