Investigating the Potential of Renewable-Hydrogen Energy Storage Systems (RHES) in Enabling Scotland’s Farming Communities Net-Zero Transition and Sizing the Proposed RHES System

Abstract

Renewable-hydrogen (H2) is a key component in Scotland’s decarbonisation plans and its implementation in farming communities can support achieving net-zero goals. HydroGlen, a demonstrative renewable-powered farming community at Glensaugh, is used as a case-study to investigate the potential of renewable-hydrogen in enabling Scotland farms’ energy transition. For our case-study farm, two renewable-hydrogen configurations (Solar-H2 and Wind-H2) were proposed, sized, and assessed to identify their capability in supplying most of the farm’s residential and commercial demands by clean renewable-energy as well as the transport demands by green hydrogen stored during renewables’ surplus. The effectiveness of the proposed configurations was then assessed against that of the Solar-Wind-H2 configuration proposed by RINA (RINA 2021). The study started by assessing the currently installed renewables-system in meeting the farm’s demands and results showed that the system can only meet 11% of farm’s commercial and residential demands and none of the transport fuel demands. To allow meeting more residential and commercial demands as well as transport demands, a hybrid Solar-H2 system was proposed with an additional photovoltaic (PV) capacity that was sized to feed a higher percentage of the demands with renewable power and a hydrogen energy-storage system to store the surplus in PV production in the form of green H2 to be used in feeding the transport fuel demands. Components of the proposed green-H2 energy-storage system (electrolyser and storage-tank) were accordingly sized. The effectiveness of the proposed hybrid PV-H2 configuration was then assessed, and results showed it was capable of supplying 35% of the residential and commercial demands from solar energy and 100% of the transport demands by green H2. This generous amount of green H2 resulted from the plenty PV daytime surplus given that most of the residential demand is not during sun availability hours. A hybrid Wind-H2 configuration was then proposed, sized and assessed. Results showed that this configuration was capable of supplying most of the residential and commercial demands from wind energy as the wind-generation profile closely matched these demands, and around 44% of transportation fuel demand by green H2. The levelized cost of energy (LCOE) was then estimated for each of the proposed hybrid configurations showing that the LCOE for the hybrid PV-H2, 0.3 £/kWh, is more cost competitive than that of the Wind-H2 of 0.4 £/kWh; thus, the hybrid PV-H2 system was recommended for the farm. Finally, a Simulink model was developed to simulate and assess the operation of the proposed PV-H2 system given that this has not been considered in RINA study.