Active Load Management of Hydrogen Refuelling Stations for Increasing the Grid Integration of Renewable Generation

Hydrogen Fuel Cell Electric Vehicles (FCEV) can help reduce carbon emissions, air pollution and dependency on fossil fuels in the transport sector. Clean hydrogen fuel can be generated by a power-to-gas process at refuelling stations equipped with water electrolysers, especially in renewable rich areas. Coupled with onsite hydrogen tanks, the fast response capability of electrolysis, could potentially turn the station demand into a flexible electricity load since the hydrogen can be stored and used when needed. This paper presents a novel real-time load management scheme that actively operates a hydrogen refuelling station to relieve thermal network constraints, handles the fluctuations from renewables, and releases network headroom for connecting renewable generation. The key components involved in the refuelling station and their operational characteristics are explicitly modelled in the analysis. The economic impact of the different operational strategies is also examined. In the case study, the effectiveness of the proposed control strategy to avoid overloading and save curtailment in the local distribution network is verified by running the real-time network simulation at 1 minute steps over a 1 hour window and 5 day window respectively. Moreover, a whole year simulation of the station operation shows that the proposed active control strategy enables wind farms in the local network to avoid 9.5 times more curtailment than under passive control strategy. The station’s net cost of electricity consumption thus can be reduced by 7.5%., by making use of excess electricity that would otherwise be curtailed. A further 5% reduction on the cost would be possible if the incentive rewards for offering network constraint management services are in place

Review of Hydrogen Production Techniques from Water Using Renewable Energy Sources and Its Storage in Salt Caverns

Hydrogen is becoming an increasingly important energy carrier in sector integration for fuel cell transportation, heat and electricity. Underground salt caverns are one of the most promising ways to store the hydrogen obtained from water electrolysis using power generation from renewable energy sources (RES). At the same time, the production of hydrogen can be used to avoid energy curtailments during times of low electricity demand or low prices. The stored hydrogen can also be used during times of high energy demand for power generation, e.g., with fuel cells, to cover the fluctuations and shortages caused by low RES generation. This article presents an overview of the techniques that were used and proposed for using excess energy from RES for hydrogen production from water and its storage techniques, especially in underground salt caverns, for the aforementioned purpose, and its feasibility. This paper compares and summarizes the competing technologies based on the current state-of-the-art, identifies some of the difficulties in hydrogen production and storage, and discusses which technology is the most promising. The related analysis compares cost and techno-economic feasibility with regard to hydrogen production and storage systems. The paper also identifies the potential, technical challenges and the limitations associated with hydrogen integration into the power grid