This post is by Dr Philippa Horton, business manager for the UK FIRES programme.
Whilst the transport sector is taking on the task to decarbonise, there is an even bigger challenge ahead around the energy needed to do it. There simply won’t be enough zero carbon energy to meet the projected demand for green transport in 2050. Plans to deliver transport services with zero emission fuels will not be enough on their own, a new focus on energy efficiency is required to make sure it can happen.
How much zero emission energy will be available for transport in 2050?
The Climate Change Committee (CCC) states that achieving net zero by 2050 will need 9-12GW of additional energy capacity every year between now and 2030. In recent years, the UK has been able to add between 3-5GW of extra capacity each year. The CCC’s projection triples that rate and is unlikely to be possible.
A more realistic approach is to assume zero emission energy will grow at a linear rate. This would provide an ambitious, but achievable 62GW in 2050. If the proportion of total UK energy used for transport were to remain at the same level, we can estimate that 23GW of zero emission energy will be available for the transport sector in 2050. This is not enough energy to meet existing decarbonisation plans.
Plans exist to eliminate carbon dioxide emissions for most modes of transport (except shipping). Zero emission road travel can be achieved through the change to electric cars, vans, motorbikes and buses; the rail network is in the process of being electrified; it is possible to power HGVs with hydrogen or an Electrified Road System (ERS); and aeroplanes can be powered by electrofuels. Biofuels are not a suitable solution for 2050, since the supply of biomass feedstock cannot be significantly expanded from today’s levels.
But, and it’s a big but, these plans all require enough zero emission electricity to directly power motors and indirectly contribute to the production of hydrogen and synthetic jet fuel. Based on today’s requirements, existing plans to decarbonise the transport sector will take nearly the whole energy budget for the UK, which is more than double the proportion of energy currently available to the transport sector.
Over half of this projected energy requirement for 2050 is for synthetic jet fuel production. Hydrogen powered HGVs make up a quarter, and public transport only accounts for a small proportion of the total.
The numbers clearly don’t add up, so a plan is needed now to address the problem.
How to help transport meet its 2050 energy budget
The answer is more efficient allocation of the energy available. Although the scale of efficiency required to meet the gap in supply is going to be large, there are significant opportunities for the transport sector to grow and prosper with zero emissions.
Here are five ways the sector could contribute to lowering energy demand:
1. We need to fly less, or not at all
If the transport sector is to stay within its 2050 energy budget, people must fly less, or not at all. The supply of biomass for sustainable aviation fuel (SAF) is already reaching the limit so, if we don’t change our travelling habits, the production of electrofuels will require more energy than is available for the whole of the transport sector. Domestic and short haul flights could be replaced by electrified rail travel, but there needs to be a strategy for long haul flights which will take a significant amount of the scarce energy budget.
2. Switch from road to rail
Rail travel is a more efficient use of energy than road transport. A full electric train can move people using 40 times less energy per passenger than a car carrying one person. More freight and people could travel by rail to reduce the energy demand for cars, vans and HGVs. There is potential for innovative business opportunities in combining freight and passenger services, flexible timetables and connecting rail travel to other transport modes to complete their journeys.
3. Use electricity, not hydrogen, to power HGVs
Hydrogen is an inefficient use of energy. For every 100kWh of zero emission electricity drawn from the grid for a hydrogen powered lorry only 23kWh reaches the lorry with the rest lost during the transmission. In contrast, 77 kWh of that 100kWh would reach a lorry travelling on an Electric Road System (ERS) which has much fewer transmission losses. A combination of a national ERS and battery electric vehicles would require much less electricity than using hydrogen.
4. Cycle more
In the Netherlands, approximately 20 per cent of all distance travelled is by bicycle, compared to only one per cent in the UK. Better infrastructure for safe travel, better services at train stations and closer local amenities would enable us to make the most of pedal power.
5. Share the journey
On average each car journey in the UK has 1.6 passengers per car. Increasing the number of passengers per car would reduce the total number of cars that need to be charged. Up to 30 per cent of energy demand by freight could be saved by optimising the location of distribution centres and by creating new collaborative networks to promote coloading, where multiple customers share the same haulage space.
The task of preventing a 2050 transport energy gap might sound daunting, but we have the benefit of foresight. With a realistic plan now, it is achievable, and rather than holding up the economy, the right environment can be created for businesses and communities to grow and prosper, powered with zero emissions.
