Sensitivities of Power-to-gas Within an Optimised Energy System

The storage of fluctuating energy production is a major challenge on the pathway to a fully renewable electricity supply. This paper investigates the role of Power-to-Gas (PtG) as a key storage technology in the fulfilment of the Energiewende. This study describesthe optimal composition and application of energy supply technologies using a detailed cost optimisation model based on data from an existing system in an actual German region. The region's electricity demand can be covered with 100% renewables at a levelised cost of electricity (LCOE) of 11 ct/kWhel. We found that the PtG capital expenditures (CAPEX) do not significantly affect the optimal system in terms of the installed capacity of PtG. Due to the high storage capacity of the existing gas grid, the use of PtG results in lower LCOE than the use of batteries. Alteration of system components towards greaterfluctuating energy production increases the need forlong-term energy storage, especially PtG, and results inhigher total costs. In summary, this investigation demonstrates the significance of Power-to-Gas.