Impact of power-to-gas storage on the integration of photovoltaic electricity into the grid

Since renewable sources will significantly contribute to the electricity supply in the future, good mid- and long-term storage solutions need to enable a decoupling of the production and consumption of electricity in order to maintain the grid stability. Besides well-approved and established storage solutions like pumped hydro facilities, other relatively new ideas of storing electricity are emerging. An example is the chemical storage of electricity in the form of gas, also known as power-to-gas. This paper contributes to the field of electricity storage by showing how power-to-gas could be used in combination with the pumped hydro facilities in Switzerland to facilitate the integration of photovoltaic sources into the electricity grid. We follow a simulation approach in order to determine the impact of power-to-gas on the grid. In a first scenario, we simulate the supply of three regions without power-to-gas as a basic scenario. In scenarios two and three, we show how a limitation of the pumped hydro capacities and the use of power-to-gas changes the situation. Our simulation shows that power-to-gas units can be efficiently combined with pumped hydro stations; this combination leads to better facility utilization for both and a better integration of photovoltaic electricity.