Research and analysis

Position statement on transport research and innovation requirements to support the decarbonisation of transport

Published 19 June 2020

Background

The Department for Transport (DfT) Science Advisory Council (SAC) convened on the 13 June 2019 to provide an independent perspective on DfT’s near, medium and long-term research and innovation (R&I) requirements for facilitating the delivery of a net-zero-emission transport system by 2050.

Transport decarbonisation is a priority area of focus for the DfT’s Chief Scientific Advisor and, in particular, ensuring that the supply from a future energy system is able to meet the demands of a future decarbonised transport system, while mitigating unintended consequences of fuel choices.

To frame the conversation, the SAC was asked to consider three overarching questions:

1. what are the challenges and opportunities associated with developing different fuels for different modes?
2. what are the potential synergies of fuels across modes and sectors, and what would be the resultant requirement on the energy system if those fuels were adopted?
3. where should government be focussing research and innovation efforts in the near, medium and long term to support decarbonisation of transport by 2050?

The session included contributions and presentations from additional academic and industry experts, and policy officials.

Introduction: an international imperative into UK law

Since the 2015 Paris Agreement, which committed signatories to hold global warming to below 2.0°C above pre-industrial levels and pursue efforts to limit warming to 1.5°C, a special report by the Intergovernmental Panel on Climate Change (IPCC) published in 2018 outlined a pressing need to hold global warming at 1.5°C against pre-industrial levels to mitigate risks associated with climate change.

Following the IPCC report the government commissioned the UK’s Committee on Climate Change (CCC) to assess what this means for current UK targets, policy and obligations. Published in May 2019, the CCC report concluded that the UK can reduce emissions to net-zero by 2050, and that this could cost the same as the existing 80% target (less than 2% of GDP). It proposed 3 cumulative packages of measures to achieve net-zero by 2050.

In response to the CCC report, the government introduced a statutory instrument into parliament on 12 June 2019, to amend the 2008 Climate Change Act and enshrine into law a 2050 net zero target for the UK. This was signed into law on 27 June 2019.

The challenge for transport

Against this backdrop, transport is the UK’s largest contributor to greenhouse gas (GHG) emissions. 28% of UK emissions originate from transport, and this does not include international aviation and shipping.

Most domestic transport emissions, approximately 90%, are from road transport and, while emissions from other sectors of the economy are falling, an increase in vehicle kilometres driven has offset increased vehicle efficiencies, resulting in only modest reductions of emissions since 1990.

With the commercial and societal challenges in mind, careful consideration and assessment of who pays for decarbonisation is required, so costs are distributed in a just way.

Known but under-developed technologies

Although the CCC report states that the transition to net zero is deliverable with known energy vectors and enabling technologies, significant research and development (R&D) is required to make those options viable for different modes and to understand where investments for the supporting energy infrastructure are required.

Modes and user cases

The development and deployment of alternative energy vectors are at different stages for different modes, and for different user cases (consumers, businesses and freight) within and across those modes. One fuel will not necessarily serve all purposes for each mode, so a combination of fuels is likely to be required to decarbonise transport. Even then, significant R&D is needed to make them viable market options, and the competing or supporting needs of other sectors must to be considered.

• road transport: Battery Electric Vehicles (BEVs) are the front-runners for light vehicles (cars and vans). For heavier vehicles, a different set of challenges are presented. Options include BEVs, but also Hydrogen Fuel Cell Vehicles (HFCVs) or overhead catenary direct electrification. Other potential options include biofuels and synthetic fuels
• aviation: for regional and national journeys, electric aviation could become viable, while hybrid aircraft could be viable for mid-flight, with traditional fuels at take-off and landing. For longer haul international flights, ‘drop-in’ fuels (synthetics and biofuels) that can work with existing engines could be an alternative to fossil fuels
• maritime: battery-electric ships are currently limited to short voyages; hydrogen fuels cells are an option, as are methanol, ammonia and biofuels as drop-in fuels for longer voyages. Each of these options come with challenges around safe and clean storage, sustainable production and use
• rail: around 80% of UK passenger travel is on the electric network, but not all of the network is electrified. Hydrogen and battery electric are options for short journeys on non-electrified lines, or short gaps in electrified lines, though both come with weight and storage issues. Freight is a particular challenge given the need to go anywhere on the network and the power/weight ratios of alternative fuels, with restrictions on the length of the train impacting on how much additional fuel can be carried

Energy vectors: demand, supply, infrastructure and mitigating unintended consequences

Balancing energy production and supply across the economy

In a 2050 net zero economy, demand for low carbon energy vectors will create direct and indirect competition across sectors. Direct competition could occur for the fuels themselves, for example hydrogen for transport and heating, while indirect competition could occur earlier in the supply chain, for example land use competition between growing biofuels and food.

Demand across the economy for energy will need to be managed. For example, current data^{[footnote 1]} and some estimates of future demand suggest that if all sectors decarbonised via electrification, then the total capacity to generate electricity would have to increase by 5 to 6 times, and cope with much larger peak power demand. Although the exact energy mix of a decarbonised economy is yet to be known, a similar challenge will exist for bio and synthetic fuels, risking a ‘battle for molecules’ across all sectors. At a system level, prioritisation between sectors and transport modes may well be necessary, so we need to understand when strategic decisions about energy vectors will have to be made.

Supporting energy infrastructure

Energy vectors require supporting infrastructure for scale up, distribution and storage, and while it may be possible to decarbonise a transport mode through a single energy vector it may not be cost effective to do so - the railways in the UK face this challenge.

Scale up and distribution for alternative vectors is a significant challenge, which can be exacerbated when you need more than one vector per mode. Where, for example, do you prioritise hydrogen distribution for HGVs if passenger vehicles are electric and don’t require a hydrogen distribution network? A similar conundrum exists for hydrogen on trains.

Thinking within modes is unlikely to be the answer; a more efficient approach for understanding where to locate refuelling infrastructure is to look at solutions across modes and across parallel sectors. Further, opportunities for how the transport system can support the energy system, through schemes such as vehicle-to-grid charging, should continue to be explored to understand how the approach can manage peaks and troughs in energy demand.

Mitigating unintended consequences of energy vectors

Transport will need to consider an energy vector’s full life cycle to ensure that any unintended consequences – such as those relating to the promotion of diesel over petrol vehicles, only to later appreciate harmful effects of nitrogen oxides – are understood and mitigated. Unintended consequences should be considered from production, through to use, and include the life cycle of supporting technology and infrastructure. For example, there are no GHG emissions from using hydrogen in fuel cells, but its production either requires electricity (for electrolysis) which will then need to come from a renewable and sustainable source, or is via steam methane reformation, which creates CO2 and will therefore require carbon capture, usage and storage (CCUS) technology to be feasible.

Drop-in fuels such as biofuels can be considered carbon neutral if their production is also sustainable, but they still emit CO2 at the point of use. Other synthetic fuels have similar challenges of balancing net GHG emission from production through to use. For example, power-to-gas or liquid fuels, which convert electrical power to a gas or liquid fuel, will require renewable forms of electricity to be carbon neutral. However, bio or synthetic fuels may emerge to be the only viable options for some modes (for example aviation and shipping), so further development of these options will still be required.

Transport demand and market framing

Consumer behaviour

Whether through purchase of a new type of vehicle, moving to greater sharing to increase utilisation, or switching modes, behaviour change will be required by consumers to enable the decarbonisation of transport.

Understanding around what will move the dial in consumer behaviour - increasing uptake of net-zero-emission vehicles, and shifting travel habits and attitudes towards sharing vehicles and rides or switching to different modes - does exist but is not from a holistic perspective. For example, issues around range anxiety for electric vehicles cannot be considered in isolation of other rationale for buying a vehicle (such as load capacity) and how consumers view their needs for different types of journeys – this includes factors balancing switching modes and convenience. Understanding this at a more holistic transport-system level may provide answers to consumers beyond their normal mode of travel.

Market framing and stimulating business investment

Without consumer demand, a clear technology path and supporting infrastructure it is challenging for business to know how, where and when to invest in net-zero-carbon technologies. There are multiple potential energy vectors for some modes, with the supporting technology at different stages of development and, while some options may appear to be more viable than others at this point, further progress and understanding will change the energy assumptions across modes, and across the wider system.

There are no clear winners across transport modes at this stage, so government and industry will need to back more than one horse in the near term to reach medium and long-term answers. This will affect business decisions which will ultimately determine whether current businesses and new entrants will survive, and shape the future job market. To meet this challenge, and the potential rewards that being a world leader in this space will bring, requires a ‘fail quickly, fail safely’ approach to innovation.

The government will need to support transformational R&D and infrastructure investments, the transition of industrial incumbents and new entrants to the market – particularly in areas where there are several potential zero emission technologies. This will require a suite of innovation tools and methods including government procurement; for example, the SAC discussion highlighted the replacement of 1000 diesel Sprinter trains over the next decade.

Time is not on our side – we need to work towards a systems view

Decisions on energy vector options in and across modes will have to be made within the next 5 to 10 years to provide a pipeline of technologies and innovations that will support their deployment and meet the 2050 net zero target. This also allows for lead times around production, vehicle life cycles and the long tail of legacy polluting vehicles to dissipate.

However, the 2050 net zero target is for the whole economy to deliver, and DfT will need to consider transport energy vectors, and the technology which enables them, in relation to the wider economy needs, including sustainable energy production, scale up and distribution.

Recommendations

There are significant near, medium and long-term uncertainties around the transport energy vectors and enabling technologies that will get us to the 2050 net zero target. It is reducing the early uncertainties, and paving the way for medium to long-term decisions, where we advise government to concentrate its efforts. Two immediate studies are required to understand the position of existing technology and energy against extant UK policy and government ambitions. These are studies of:

1) viability of energy vectors in different modes: a systematic summary of transport decarbonisation options for each mode is required, mapped against those vectors currently under consideration or being developed for each mode under existing UK policy. The study should consider the economic cost and benefits for use of each vector against technical readiness and lead times for development; the infrastructure requirements for delivery at scale; and current take up of those vectors for different user cases and the business models which support them. This includes passengers or freight, journey types (such as local, regional, national, international), vehicle lifetimes and size and weight considerations. It should also include an outline of behavioural considerations for long-term adoption.

2) full life cycle impact of potential transport energy vectors, and potential synergies across that system: in parallel, a closer examination is required of the overall ‘well to wheel’ impact of potential transport energy vectors and any unintended consequences within that life cycle. This study should also look to understand if energy vectors increase in viability when produced, scaled, distributed and stored in partnership with other sectors and/or become part of the energy grid itself. Enhanced analytical models to understand the future energy system should be explored as part of this study.

These studies should inform DfT of how stakeholders from across government and existing funding programmes through UK Research and Innovation (UKRI – Innovate UK and the research councils)^{[footnote 2]} can interact to support the 2050 ambition, and provide the necessary information to:

3) develop an R&D roadmap for decarbonisation of transport, which aligns the science, research and innovation horizon with policy ambitions or targets, and the transport technologies or services which are being developed in parallel, such as automation and ‘mobility as a service’.

4) inform the development of a five-year UKRI research programme, specifically aimed at managing the uncertainties and informing future decisions around energy vectors, supporting technology, infrastructure, consumer and business behaviour.

Finally, more broadly, the DfT should consider:

5) what near-term options are available to support long-term decarbonisation of transport through procurement. In particular, where there may be barriers to net zero emission transport innovation in procurement processes, or where opportunities arise to shape/mandate the use of zero-emission transport options as part of a procurement exercise. The upcoming replacement of Sprinter trains may be an early opportunity to innovate here on vehicles which have a long service life.

Footnotes

1. Multi-vector energy analytics project, A.I.G. Wilson. Challenges for the decarbonisation of heat: local gas demand vs electricity supply (winter 2017/2018) Winter 2017/2018, P. Rowley, A.I.G Wilson, and R. Taylor, UK Energy Research Centre, 2018. ↩

2. These include the Faraday battery challenge, Driving the electric revolution programme, and others. ↩