What can be done to achieve UK transport decarbonisation by 2050?

Real world learning from the rapid growth of Electric Vehicle models (EV) on the market has allowed us to better represent the cost profile for electric vehicles in our scenario modelling. So far, the most popular alternative has been the non-plug-in hybrid, internal combustion engine (ICE). However, the provision of a grant towards the cost of a new plug-in electric vehicle has helped spur the adoption of plug-in hybrid electric vehicles (PHEVs), and pure battery electric vehicles (BEVs).

Over the longer term, our scenarios also address the government announcement for a ban on new sales of traditional ICE vehicles from 2040. As we do not know if this ban will apply to non-plugin hybrid ICEs we have ensured that this uncertainty is reflected in both updated scenarios.

In Clockwork, the analysis shows that light vehicle manufacturers respond to fleet average CO2 targets by developing a wider range of non-plug-in hybrid ICE models. Over time these become mainstream and traditional ICE sales fall away. BEVs appeal to some consumer segments as a low carbon lifestyle choice, but play a more modest role than some anticipated, with PHEVs emerging as the preferred low carbon alternative. By 2050, Clockwork shows that electrification makes up 20% of all road transport energy consumption, as natural gas is rapidly adopted as a transitional HDV fuel before more comprehensive low carbon alternatives are adopted.

In this scenario, hydrogen fuel cells fail to take off due to a lack of any widespread investment in refuelling infrastructure and lack of consumer appetite for these more expensive models. Overall, across all road transport, including cars, vans, buses and other medium and heavy-duty vehicles, Clockwork sees a significant reduction and diversification in final energy consumption.

In other areas of the transport industry, Clockwork shows advances in aeroplane efficiency and aviation operations meaning that overall emissions from aviation sector remain on a par with 2010 levels. Shipping demand also sees some growth in this scenario, but emissions are again held steady, thanks to alternative technologies in the form of dual-fuel ships burning a combination of liquid fuel and natural gas.

Looking at Patchwork, the light vehicle market quickly diversifies, with non-plug hybrid ICEs appealing to many as a familiar alternative. With a ban on sales of new ICEs and hybrid ICEs from 2040, the market shifts towards PHEVs and pure BEVs, which requires substantial upgrades to the electricity networks.

As in Clockwork, final energy consumption across all road transport peaks in 2020, as efficiency improvements, including substantial electrification, drive reductions year after year. By 2050, electricity accounts for 70TWh of road transport energy use. Meanwhile liquid fuel use falls away dramatically from a peak of 430TWh to just 80TWh in 2050. The Patchwork scenario shows that natural gas acts as a lower carbon alternative to diesel in HDVs, making up 75% of all HDVs in 2040. Hydrogen also emerges as an important energy vector in transport, accounting for 10% of final energy consumption by 2050.

It is important to note that, while we do not capture air quality in our energy models, we have a proxy in the form of fleet average CO2/km emissions targets for new vehicles. In both scenarios these targets tighten over time. Although ongoing improvements to ICE performance are assumed in our model, the targets in our scenarios are sufficiently strict that they can only be met through the increased uptake of alternative vehicles such as hybrid ICE, PHEV, BEV.