Which way to net zero? : a comparative analysis of seven UK 2050 decarbonisation pathways

Since the UK’s Net Zero greenhouse gas emissions target was set in 2019, organisations across the energy systems community have released pathways on how we might get there – which end-use technologies are deployed across each sector of demand, how our fossil fuel-based energy supply would be transferred to low carbon vectors and to what extent society must change the way it demands energy services. This paper presents a comparative analysis between seven published Net Zero pathways for the UK energy system, collected from Energy Systems Catapult, National Grid ESO, Centre for Alternative Technology and the Climate Change Committee. The key findings reported are that (i) pathways that rely on less stringent behavioural changes require more ambitious technology development (and vice versa); (ii) electricity generation will increase by 51-160% to facilitate large-scale fuel-switching in heating and transport, the vast majority of which is likely to be generated from variable renewable sources; (iii) hydrogen is an important energy vector in meeting Net Zero for all pathways, providing 100-591 TWh annually by 2050, though the growth in demand is heavily dependent on the extent to which it is used in supplying heating and transport demand. This paper also presents a re-visited analysis of the potential renewable electricity generation resource in the UK. It was found that the resource for renewable electricity generation outstrips the UK’s projected 2050 electricity demand by a factor 12-20 depending on the pathway. As made clear in all seven pathways, large-scale deployment of flexibility and storage is required to match this abundant resource to our energy demand.