Polymer electrolyte membrane electrolyzer and fuel cell system characterization for power system frequency control
Christian Peter, Evangelos Vrettos, Félix N. Büchi
Abstract
This work focuses on tests for control reserve of a novel Power-to-Gas-to-Power platform based on proton exchange membrane technologies and on pure oxygen instead of air in the re-electrification process. The technologies are intended as a further option to stabilize the power system, therefore, helping integrating renewable energy into the power system. The tests are based on the pre-qualification tests used by Swissgrid, but are not identical in order to capture the maximum dynamics by the plants. The main characteristics identified are the ramping capabilities of ±8% per unit per second for the electrolyzer system and ±33% per unit per second for the fuel cell system. The ramping capabilities are mainly limited by the underlying processes of polymer electrolyte membrane technologies. Additionally, the current and projected round-trip efficiencies for Power-to-Gas-to-Power of 39% in 2025 and 48% in 2040 are derived. Furthermore, during the successful tests, the usage of oxygen in the present Power-to-Gas and Gas-to-Power processes and its influence on the dynamics and the round-trip efficiency was assessed. In consequence, fundamental data on the efficiency and the dynamics of the Power-to-Gas-to-Power technologies is presented. This data can serve as basis for prospective assessments on the suitability of the technologies investigated for frequency control in power systems.