In the UK it will be compulsory for vehicle retailers to sell a proportion of electric powertrains (the system which propels the vehicle forward) from 2024, rising each year until 2030 when the sale of new petrol and diesel combustion powered cars and vans will be banned entirely, including all hybrids. And recently the government announced just over £600 million of investment to support infrastructure and speed up the rollout.

However Professor Chris Smith, Director of the new Centre for Future Clean Mobility at Exeter, says: “Road cars and vans account for about 40–50% of transport emissions, with the other 50–60% coming from heavy goods vehicles (lorries), construction vehicles, rail vehicles, ships, and static diesel-powered machinery, and this portion has received far less attention to date. This is where more action is desperately needed and where we focus our efforts.”

The Centre for Future Clean Mobility specialises in developing zero emissions electric, hydrogen and hybrid powertrains. Researchers partner with businesses to develop zero or low-emission, ultra-efficient integrated power systems for applications in the marine, off-highway, rail, HGV, defence, and energy sectors.

Chris says: “There are several million diesel engines in the UK, but about 13 million or less than half of the total are in road vehicles, with many more large and inefficient engines in large, complex, and expensive vehicles working away on our railways, beside our roads, on construction sites, in ports, and many other industrial sites. These are often emitting CO2 and other pollutants right in the middle of our cities. We urgently need to convert these powertrains to zero emissions systems.

“We’ve got quite a few partnerships at work at the moment, some of which are too early for public release. For example, in 2018 we started working with Quattro Group, who are the largest provider of maintenance and repair services to Network Rail amongst other things. One of the aims of this partnership was to design a new clean powertrain for road-rail vehicles, which are used to maintain our railways, many of which go past houses, schools and hospitals in urban settings. Quattro asked us to help them remove all emissions from their fleet of vehicles and I expect some exciting developments for these vehicles to be announced soon.”

One of the longest-running partnerships has been with Supacat, a world-leading defence and high mobility vehicle manufacturer. The team worked to convert a unique six-wheel drive high mobility vehicle – the All-Terrain Mobility Platform, into a new hybrid or zero-emissions vehicle, now called the H-ATMP. The vehicle can be air-dropped, pull heavy loads up steep slopes and through rough terrain, and is also amphibious. It is the first military vehicle of its kind not powered by diesel, with the battery-electric version being just as capable as its diesel predecessor.

At the core of most of the Centre’s work are electric motors – highly efficient, compact and incredibly powerful. Electricity for these motors can come from batteries or increasingly from hydrogen fuel cells.

Chris says: “It is almost impossible to simply take an electric or hybrid powertrain from a road car and transplant it into a crane, a crew transfer work boat, a 44 tonne HGV, or a rail vehicle. In many cases the power demands are very different and much greater, and you will end up requiring so many batteries that you have to double the size of the vehicle or vessel to house them. This tends to be where hydrogen comes in as a viable energy store. The jury is still out on hydrogen in cars, but for much higher power demands it is probably one of the best, if not the best, solutions.

“We’re currently working on some prototypes of hydrogen – electric battery hybrid powertrains, which seem to be the most viable solution for heavier vehicles and vessels demanding longer range and higher power. Although there is some nervousness around hydrogen, it is so far proving to be safe. If we were inventing petrol as a fuel today we would probably have bigger concerns, yet we seem to have managed to use petrol pretty safely for a long time. We are working with Ecomar Propulsion on the design of a new class of zero emissions powertrains, many of which involve hydrogen fuel cells, for work boats such as crew transfer vessels, harbour tugs and ferries. All we can say now is to expect some exciting developments in 2022. The big challenge is getting the infrastructure and public policy in place to support take up of hydrogen.”

In September 2021 the Centre moved into its new home at Exeter Science Park, where there is space for 20 staff and a new clean powertrain assembly and test facility that allows the team to assemble and test powertrains with outputs up to 900 kW (1200 BHP). This facility is unique to date, and is made freely available for other researchers from universities or industry to develop, assemble and test new clean powertrains.

“It’s a really exciting time for the Centre.” says Chris. “There is a huge interest from industry in developing sustainable solutions and we are able to not only affect real and significant changes in emissions right now, but also train the next generation of engineers so they keep innovating and providing greener vehicles and vessels.”