Status quo and perspectives of biogas production for energy and material utilization

Biogas is in many respects a serious alternative to other fossil resources and complements other renewable energy sources from wind and sun. Biogas can be produced in many places decentrally. Its energy potential is high, and it is widely used in the EU and all over the world. With more than 16,000 ktoe of oil equivalent in the EU in 2016, it corresponds to approximately 8% of the total primary energy produced by renewable energies in the EU, produced with nearly 17,000 biogas plants. Nevertheless, the production costs of biogas and its products like energy, heat, and fuel are still too high. Kost et al. (2018) show a comparison of electricity generation costs of different renewable energies and their future potentials. While electricity from huge biogas plants offers generation costs from 10 to 15 ct/kWh, electricity from onshore wind and huge solar systems offers generation costs from 4 to 8 ct/kWh. Although substantial progress has been made with regard to substrate use, production techniques and market designs, many more innovations are needed throughout the biogas value chain for it to be competitive in energy markets without high subsidies. As several papers in the special issue on biogas show, there are numerous innovations and product designs with regard to energy and material uses that could maintain or even increase the importance of biogas production both within and outside of the EU. There are many potential benefits of biogas, as it offers high shares of produced renewable energies as well as large amounts of material products like digestates and in future maybe products of higher value such as proteins or lactic acids.