Quantifying the value of hydrogen in the low carbon energy future using a whole system approach

Great emphasis has been placed on decarbonising the UK electricity sector, shifting generation mix by replacing fossil fuel based generators with renewable generation. The percentage of electricity produced from renewable sources exceeded 25% in the UK for the first time in 2015. However, there is evidence that the UK is unlikely to meet its 2020 target in time, due to the slow progress in decarbonising the heating and transportation sectors. A big push is needed on heat and transport to avoid losing momentum. There is an importance of the energy system not being developed in isolation. Given that the electricity sector will continue to accommodate more renewables, leveraging low-carbon electricity to help decarbonise heat and transport becomes increasingly appealing. Power-to-Gas provides a potential solution by using renewable energy from the decarbonised electricity and making use of existing gas infrastructure. Power-to-Gas is the process of converting electricity into hydrogen gas by rapid response electrolysis and subsequent injection into the gas network for heating and transportation. Through the energy vector of hydrogen, rather than electricity, both the gas and electricity network infrastructure can be better used to help increase the renewable penetration and also facilitate a transition from natural gas to a ‘greener’ mixed gas.
Many issues surrounding renewable Power-to-Gas are currently uncertain and require analysis. One such challenge is the lack of available tools which can study hydrogen in both the electricity and gas system together. This whole system approach is essential to capture the level of coincidence between generation, transport and consumption of hydrogen across the electricity and gas networks, so that the system potential for accommodating power-to –gas may be quantified. The purpose of this research project is to set up a whole system analytical framework which is capable of identifying the operational redundancy and stress on the future low-carbon electricity system, and assessing the value of leveraging alternative energy vectors, such as hydrogen, in decarbonising other energy sectors. This research focuses specifically on modelling both electricity and gas systems with essential spatial and temporal resolutions. The preliminary analysis shows that power-to-gas availability increases with greater capacity of renewable electricity generation but also shows significant regional imbalance and daily and seasonal variance, which could cause significant stress on parts of the gas network, limiting scope for renewable hydrogen.