Increasing installable photovoltaic power by implementing power-to-gas as electricity grid relief – A techno-economic assessment

Abstract

The integration of renewable electricity generation poses challenges for today's energy system. Since renewable potentials are geographically unevenly distributed, solutions to overcome bottlenecks such as grid congestion are necessary to raise as much renewable potentials as possible. In specific, a part of Austria is characterised with high photovoltaic installation inquiries and low electricity demand. Electricity grids are designed to cope with today's loads, therefore the integration of inquired photovoltaic would overstrain the built infrastructure. In this paper we investigate how power-to-gas can ease this photovoltaic related grid strain. The feed-in of hydrogen into natural gas transmission pipelines and the usage of hydrogen and biogas from local fermentation plants for methanation feeding synthetic natural gas (SNG) into local distribution grid is assessed in various scenarios. Based on the technical assessment results, an economic evaluation of each scenario is performed to determine generation costs of hydrogen or SNG. Depending on the electrolysers location in the electricity grid, the installable photovoltaic power can be increased significantly without causing electricity grid congestion. Costs for hydrogen and SNG vary across each scenario, mainly influenced by CapEx for electrolyser and methanation as well as electricity purchasing costs.