The virtuous integration of biogas production with other activities is certainly possible. This is demonstrated by the “Lukon” which two companies have adopted, one German and one Polish. As part of the project, a biogas plant is complemented by a photovoltaic plant and an algae cultivation system. The digestate from the biogas plant acts as a fertiliser for the algae, as does the recovered CO2. Thanks to this approach, naturally grown algae can be sold directly on the market.