Land and water requirements for the supply of renewable heating and transport energy using anaerobic digestion and water electrolysis: A case study for the UK

This paper considers nine scenarios for the supply of all the required energy for domestic heating and road transport in the UK from renewable resources and compares their land and water requirements. The scenarios use hydrogen and/or methane as main energy vectors, with anaerobic digestion (AD) of organic waste and energy crops, water electrolysis (WE) and electricity from solar PV panels. The land requirements of WE-based scenarios are much lower than for energy crops. If WE only is used, the land requirement is 1.52 Mha (6 % of the total UK land), which can be decreased by 30-34 % (1.00-1.07 Mha) if WE is used with AD of organic waste. The lowest land requirement (0.73 Mha) is obtained with electric vehicles for transport and WE and AD of organic waste for heating. For most scenarios, the direct water requirements are in the range 40-126 Mt/year (1-4 % of the drinking water supply in the UK). This study indicates that it is possible to supply all the required energy for domestic heating and road transport in the UK from renewable resources, in particular solar PV panels and organic waste, with a moderate impact on land and water use.