Biogas power when wind and sun fail: a Fraunhofer solution for digital retrofits
An industrial computer in the control cabinet is meant to prepare biogas plants for windless, dark periods: Fraunhofer IGB links operating data with electricity price forecasts instead of costly gas storage.
Symbolic image · Photo: Florian Gerlach (Nawaro) / Wikimedia Commons, CC BY-SA 3.0 (cropped and resized)
Biogas plants in Germany are to supply electricity mainly when the sun is not shining and the wind is not blowing. The amendment to the Renewable Energy Sources Act planned for 2027 is set to limit the number of operating hours eligible for payment. For the operators of almost 10,000 plants in Germany, the timing of grid feed-in will therefore decide profitability. According to the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, expanding gas storage is likely to pay off for only some older plants.
IGB has therefore developed a purely digital solution: an edge device, an industrial computer, is connected directly to the existing plant control system without interfering with it. It collects data such as digester temperatures, gas composition and gas storage levels, stores them over longer periods and can combine them with electricity price or weather forecasts. "For longer-term analyses, forecasts or overall optimisation, the data are often not available in the required form," says process engineer Alexander Laug.
Processing takes place on site; operating data do not necessarily have to go to an external cloud. On this basis, forecasts, soft sensors for values that are not measured directly and AI-supported optimisation are to deliver concrete operating recommendations. According to IGB, the principle can also be transferred to other facilities, such as wastewater treatment plants or agricultural irrigation.