ITEN: Sustainable Transport


Helen Viner, Vijay Ramdas and Martin Lamb on why it’s time to get real about decarbonising transport

The remarkable Swedish teenager Greta Thunberg has brought focus and a growth in the sense of urgency surrounding the task of reducing emissions of greenhouse gases (GHG).

This poses a serious challenge to transport professionals, as it is generally recognised that transport is a major contributor to overall GHG emissions and is the sector that is proving most resistant to reduction. It is doubly relevant, as the transport sector also stands to be severely impacted by some of the projected climate change and extreme weather events, such as sea level rise, severe storms and flooding and extreme temperatures.

Since 1990, UK annual CO2 emissions have dropped by nearly 40 percent and other sources of GHG have dropped by nearly 60 percent [1]. In this period, unlike most other major sectors, emissions from the transport sector have remained stubbornly close to the 1990 level and now represent the largest single sector, at 33 percent of overall UK CO2 emissions (Figure 1). The greatest share of CO2 emissions arises from road transport, primarily from cars, heavy goods vehicles and vans (Table 1).

[1]2018 UK Greenhouse Gas Emissions, Provisional Figures – Statistical Release. Department for Business, Energy & Industrial Strategy, March 2019.

In its tenth annual report to Parliament, the Committee for Climate Change (CCC) reported that while the UK had led the way in the G7 to date, showing the most substantial emissions reduction during a period when economic growth was above the G7 average, there is a high risk we will fail to meet the next carbon budgets[3]. These targets, covering the periods 2023-2027 and 2028-2032, will require a reduction of around 10 MtCO2e (million tonnes of carbon dioxide equivalent) each year and it is clear from the values in Figure 1 why a change is needed urgently in transport. The UK Government announcement on 12 June 2019 that the UK will set a legally binding target for net zero greenhouse gas emissions by 2050, will accelerate the need for these reductions.

“In June 2019 the UK Government announced that the UK will set a legally binding target for net zero greenhouse gas emissions by 2050, accelerating the need for these reductions”

The challenge is complex and will require a range of solutions. The CCC report identifies a host of actions regarding the regulation of, and incentives for, new clean vehicles and modal shift to deliver a significant reduction in the miles driven by cars, the biggest single source of CO2. The additional detail in the UK Department for Transport’s “Road to Zero”[4] aligns with the CCC recommendations. However, it also emphasises the scale of the challenge: while detailed, this document does not give confidence that change can be achieved within the timescales needed.

There are two key areas in which action is needed: decarbonising fuel supply and achieving a shift to low-carbon travel modes. In our view, the critical requirement to facilitate the transformational change needed, is the provision of suitable infrastructures for generating and supplying green energy, for reducing (to near zero) the burning of fossil fuels for propulsion and to transition to lower-carbon modes of transport. This latter topic will be covered in a future article.

For cars, electric and hybrid vehicles are market-ready although sales are hampered by high purchase price, limited choice of models/high waiting times for new vehicles and low range under electric power. Many of these will improve as battery technology develops and prices continue to fall but, at present, the UK continues to lag behind the EU in the take up of hybrid and electric cars, with a growth of 2.9 percent in the UK versus 40 percent in the EU during the first quarter of 2019[5].

The viability of fully electric vehicles as a choice for consumers and, for hybrid vehicles, the proportion of miles driven under electric rather than fossil power, will be influenced by how frequently the vehicles can be, or are charged. While schemes such as Low Emission Zones in city centres can incentivise the purchase of hybrid vehicles, they will not able to discriminate the regime in which the vehicles are powered. Drivers consequently need easy access to charge points, and the electricity provided needs to be generated from renewable sources; both can be considered to be infrastructure projects. There are currently around 23,000 public charge points at nearly 9,000 locations in the UK but many more are needed; for example, Aurora Energy Research has reported that electrification can deliver a 90 percent reduction in emissions[6] and has suggested that between 1 and 3 million charging outlets would be needed, covering fleet vans, workplace commuter charging, public car parks and motorway service stations.

[2] Final UK greenhouse gas emissions national statistics 1990-2017. Department for Business, Energy & Industrial Strategy, March 2019.

[3] Reducing UK emissions, 2018 Progress Report to Parliament. Committee on Climate Change, June 2018.

[4] The Road to Zero, Next steps towards cleaner road transport and delivering our Industrial Strategy. Department for Transport, July 2018.


“While schemes such as Low Emission Zones in city centres can incentivise the purchase of hybrid vehicles, they will not able to discriminate the regime in which the vehicles are powered”

It is an exciting opportunity: with infrastructure that can provide adequate connection, electric vehicles can become a part of the additional storage capacity needed to buffer the fluctuating energy output from solar and wind generation. After all, most vehicles are stationery for most of the time. Furthermore, the introduction of ‘smart’ connection to the grid (to facilitate charging during periods of low energy demand) can make better use of existing grid capacity by reducing demand at peak periods. Government grants for installation of charging points will be helpful, as will new EU rules introducing requirements for charging stations for non-residential buildings. It remains to be seen whether they will be sufficient to get us to a tipping point whereby electric vehicles become the natural choice to consumers, including those with no off-street parking

Low carbon options for powering HGVs have either batteries or hydrogen fuel cells as the primary energy source with various options for recharging and extending their range. All these solutions also require new infrastructure, either for generating and supplying the hydrogen, or for significant upgrades to the grid to supply the electricity needed for rapid charging. Electric Road Systems with direct power to vehicles (via overhead pantograph, “third rail”, or inductive transfer systems) could also be part of the solution in some locations.

Interestingly, Ricardo’s recent analysis predicts that the costs for the infrastructure needed for most options, when totalled up to 2060, will be less than the costs associated with the current scenario despite the up-front capital costs[7]. This is largely a result of the greater fuel-efficiencies compared with diesel: most options require only 30 to 45 percent of the energy that would be used under the current scenario. All the options considered are technically feasible: there are already a small number of hydrogen fuelling stations in the UK; 350kW rapid charging facilities are being rolled out in Europe and several trials of Electric Road Systems.

[6] Opportunities in Electric Vehicle Charging at Commercial and Industrial Sites. Aurora Energy Research Ltd., 2018.

[7] Zero Emission HGV Infrastructure Requirements. Ricardo report ED12387 for the Committee on Climate Change, May 2019

Of course, this energy needs to be generated, and from renewable sources. Again, Aurora has estimated that charging EVs could correspond to an annual demand of 11-15 TWh and Ricardo’s estimates put energy use by HGVs in 2060 at maybe double this. Combined, this would represent around 10 to 15 percent of current UK electricity generation[8]. Even with the current mix of sources for electricity generation, achieving this transition would lower GHG emission compared with burning petrol or diesel for propulsion.

“A sense of urgency, supported by consistent policies and long-term strategies, is critical to enable the drastic reductions in emissions from road transport that are needed”

However, worldwide, the capacity for renewable energy generation is growing strongly: it has nearly doubled since 2010, to 2.4 TW (the UK grew by 350 percent, to nearly 45 GW). With this growth has come falling prices and there seems agreement that it is feasible to generate a high proportion of national energy demands (60 to 80 percent) using renewable sources[9]. There are differing views about the prospects of further increases above this level, which means that alternatives strategies, for reducing energy demand (e.g. shifting to low-carbon modes of travel), are also needed.

A sense of urgency, supported by consistent policies and long-term strategies, is critical to enable the drastic reductions in emissions from road transport that are needed. It was welcome news that one of Theresa May’s last acts as UK Prime Minister was to announce legislation that would commit the UK to a binding target on GHG reduction by 2050. It needs to be followed up by actions that deliver the new infrastructures and incentivise the transition that can lead to this reduction in practice.

[8] Digest of UK energy statistics, chapter 5 (electricity). Department for Business, Energy & Industrial Strategy, 2018

[9] Can the world thrive on 100 percent renewable energy? The Economist, 13 July 2017.

The International Transport Experts Network (ITEN)

ITEN is a network of small, independent transport consultancies providing evidence-based research, consultancy and strategic advice to public and private clients. Working together we provide multi-disciplinary expertise, including:

· Vehicle safety

· Highway infrastructure and operations

· Railway systems

· Future transport systems and technology strategy


Helen Viner is iDirector of Enodamus Ltd

Vijay Ramdas is Director of Truvin Analytics

Martin Lamb is Managing Director of Maple Consulting

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