Electrolytic hydrogen production for electricity market optimisation of refuelling stations and renewable power integration into electricity networks: Presentation

Hydrogen refuelling stations with on-site electrolytic hydrogen generation are currently being developed and deployed in the UK to support an increasing number of hydrogen internal combustion engine (HICE) vehicles and hydrogen fuel cell electric vehicles (HFCEV). Electrolytic hydrogen production with hydrogen storage can be used as a controllable load on the network, to take advantage of price variations in the electricity network [1], or to help with the integration of renewable resources on constrained networks, for example by generating hydrogen at times where generation would otherwise be curtailed [2]. Recent research carried out at the University of South Wales’ Hydrogen Research and Demonstration Centre will be presented, investigating the use of electrolytic hydrogen generation. In [1] an optimisation routine has been developed to minimise the electricity costs of operating a hydrogen refuelling station exposed to market prices. The performance of a hydrogen refuelling station is simulated, finding that the optimisation routine is capable of minimising costs, but that this is dependent on the level of hydrogen demand. Increasing the number of cars refuelled per day increases the electrolyser utilisation as shown in figure 1a, but increased utilisation limits the ability of the electrolyser to take advantage of electricity price variations as shown in figure 1b, where the electrolyser is in almost constant operation when serving 20 cars per day.

Figure 1: a) effect of number of cars refuelled daily on electrolyser operation and hydrogen demand not met. b) Electrolyser operation for 15 and 20 cars refuelled per day. [1]
Electrolytic hydrogen generation can also be used to support electricity distribution networks to integrate renewable generation, either by supplying a hydrogen demand from vehicles through a network of refuelling stations [2], or through applications such as power to gas. Recent research into the ability of electrolytic hydrogen generation to provide electricity network support will be described.
References
[1] Carr, S., Zhang, F., Liu, F., Du, Z. and Maddy, J Optimal operation of a hydrogen refuelling station combined with wind power in the electricity market, International Journal of Hydrogen Energy, In press
[2] Carr, S., Premier, G.C., Guwy, A.J., Dinsdale, R.M. and Maddy, J., 2014. Hydrogen storage and demand to increase wind power onto electricity distribution networks. International Journal of Hydrogen Energy, 39(19), pp.10195-10207.