The Potential of Biogas; the Solution to Energy Storage.

Energy storage will be essential for balancing the renewable energy systems of tomorrow, especially if excess electricity from wind and solar power requires immediate utilization. The use of biogas as a carbon source can generate carbon dioxide-neutral carbon-based energy carriers, such as methane or methanol. The utilization of biogas today is limited to the generation of heat/power or biomethane (first-generation upgrading); both processes disregard the potential of the coproduced carbon dioxide during the fermentation process. By using renewable energy, biogas upgrading systems can convert carbon dioxide into hydrocarbon-based high-energy-density fuels, which can replace fossil-based fuels for applications in which they are hard to decarbonize. The possibilities for the future utilization of biogas are discussed, and the terminology for "second-generation upgrading" is introduced to help research and development within this field. It is believed that second-generation upgrading of biogas will have a huge potential for dynamic energy storage.