Hydrogen-based solutions to help the electrical grid management: Application to the Terceira Island case

Abstract

The need for decarbonization has become an urgent objective being pursued across borders and sectors. The energy sector is one example to follow, with the penetrations of renewable energy sources increasing year after year and already having an impact on carbon emissions. Despite their benefits, as these penetration levels grow, grid frequency is likely to be affected, namely in small, isolated power systems. Part of this instability is caused by the different types of connections to the grid used by most renewable energy sources. These converter-connected technologies do not contribute to the grid's inertia the same way synchronous generators do, therefore the difficulties in keeping the frequency under control. Focusing on the behaviour of the system's frequency, following some disturbances, a grid model of the Portuguese Terceira Island is created to assess the potential benefits of using hydrogen technologies (electrolysers and fuel cells) to provide grid services. In this paper, two scenarios are analyzed, the system's frequency response to large imbalances and steady-state imbalances stemming from load and wind power forecasting errors. The results reflect how the frequency behaviour is affected by the amount of the system's inertia, synchronous generators characteristics, and the presence of electrolysers and fuel cells. Hydrogen systems impact positively on the frequency containment after large disturbances, the impact related to the response to steady-state imbalances being lesser and prone to affect the stacks lifespan.