Renewable energy technology does not simply produce energy, heat and transport fuel, but also offers the opportunity to live in the footsteps of a reasonable future development. In Europe and other industrialized regions, the main reason for the development of renewable energy is the environment, in particular the concern in relation to global climate change and the need to improve security and diversity of energy supply. In the developing countries, they promise a new hope for renewable primary energy supply in regions without conventional energy and provide an opportunity for sustainable development. Production of "green energy" from biogas, which is among the renewable energy sources, promises an environmentally less damaging way of obta...