Operating Methods for Electrolyzers Coupled to Wind Turbines

Inhalt:
The transition of the energy system towards a carbon-neutral system and the necessary sector coupling impose a heavy burden on the power grid and renewable electricity generation. The flexibilization of consumption and generation, as well as energy storage, are promising possibilities for the transition. This raises the question of how electrolyzers, as flexible consumers, should be operated to minimize the impact on the grid. To study this, we systematically investigate operating methods for electrolyzers coupled to wind turbines to utilize excess energy and mitigate the impact on the power grid. Various operation methods are introduced and compared: regular, peak clipping, mixed, and market-based operation. In addition, regular and market-based operation are complemented with short-term battery storage to smooth the power input to the electrolyzer. The impact of these methods on a generic medium-voltage power grid is evaluated for various power ratios between the electrolyzer and the wind turbine. We assess how coupling an electrolyzer to a wind turbine mitigates line loading and voltage limit violations in the grid. The results show that even small electrolyzers with only a tenth of the wind turbine peak power can reduce the limit violations by up to 43 % and reduce grid reinforcement needs accordingly. However, large electrolyzers are necessary to eliminate the violations. The study is part of the "Northern German Living Lab" and uses future electricity price predictions from Fraunhofer IEE.