Operating strategies for biogas plants - conflict of objectives between advantageous grid and economically oriented operation

In an intelligent energy system, ''smart grid'' and ''smart market'' must go hand in hand (Aichele et al., 2014). Changes to the legal framework, especially the German Renewable Energies Act (EEG), aim at bringing in line the requirement for increased generation of renewable energy with the market and system integration of renewable energies (see Schwarz, 2014). This determines whether the operation of a modern renewable energy plant has both the maximisation of profits (smart market) as well as the easing of the higher-order grid (smart grid) as its goal or whether it is only geared towards one aspect. The agricultural biogas producer is the focus of this interdisciplinary paper. He can either use the electrical energy generated by his plant himself in an economically orientated way or design the supply to the upstream grid in a way that is advantageous for the grid through the increased flexibility of generation and consumption. Through a two-stage simulation of the impact on the grid and the operational performance, the differences with regards to the strain on the grid and the financial losses to the farmer are quantified. If is clearly shown that none of the legislative and regulatory incentive schemes favour a mode of operation that is advantageous for the grid.