10. Biomethane and Natural Gas

One of the crucial requirements for distributed generation is the presence of an efficient and sufficiently encompassing network for easy transfer of energy from sources of production to the end-user: allowing continuous variation of these players both in time and place. The natural gas grid—constructed over several decades—has these properties, and provides an immediate opportunity for the implementation of decentralized generation and use. Biogas from anaerobic digestion, due to its high methane content, is the ideal energy carrier to substitute non-renewable natural gas. In order to conform to natural gas quality, the biogas has to be upgraded, which entails especially the removal of carbon dioxide and sulphur compounds, so that it becomes biomethane. Harmonized and univocal regulations are called for to establish the conditions and methods of biomethane feed-into the natural gas grid, to promote a smooth transition from the one energy vector to the other.