Maxine Perella finds out how UK hauliers are attempting to drive down emissions

Few would oppose the proposition that the freight transport sector needs to reduce emissions. The challenge lies in engineering a decarbonisation solution that is compatible with the diverse range of vehicle configurations, weights and fleet sizes. According to the government’s Freight Carbon Review 2017, heavy goods vehicles (HGVs) account for around 17% of UK greenhouse-gas (GHG) emissions from road transport, while being responsible for just 5% of vehicle miles.

‘There’s no one silver bullet to help to reduce freight emissions,’ says Rachael Dillon, former climate change policy manager at the Freight Transport Association (FTA). ‘Technology that is right for one vehicle may not be right for another. A refuse vehicle dependent on stop-start operations, frequent stops and low mileage is doing something entirely different from a supermarket retailer trucking up and down the motorway.’

In the review, which was published in February, the government acknowledged that a range of measures was needed if the road freight sector were to make a meaningful contribution to the UK’s target for emissions to fall 57% below 1990 levels by 2032, in line with the fifth carbon budget.

Improving performance

Although the delayed emissions reduction plan (known as the Clean Growth Plan) should outline the steps the government is proposing to decarbonise transport, there is still uncertainty about the right solutions for road freight. ‘This will necessarily be an evolving picture over time as HGV technologies continue to emerge and develop,’ the review points out.

It identifies five themes the sector could take forward to improve emissions performance. These centre on eco-driving, optimising fleet design, reducing road miles through modal shift, alternative fuels and more radical proposals such as electric trucks.

Dillon says the adoption of alternative fuels is already proving fruitful for some of the UK’s large freight operators: ‘The most progression has been with the gas vehicles over the past few years, so being able to switch from diesel to gas, and ultimately biomethane – that’s been the most viable solution, certainly for heavier trucks.’

One such operator is Waitrose. In February, the retailer rolled out a fleet of ten biomethane compressed natural gas (CNG) powered trucks, each capable of an operational range close to 500 miles. The Scania-built lorries are said to be the first in Europe to use twin 26-inch diameter carbon fibre fuel tanks, which store gas at 250 bar of pressure to enable such high mileage.

By running entirely on biomethane, the trucks emit 70% less CO2 than diesel. Waitrose calculates that each lorry will save more than 100 tonnes of carbon a year. Although the upfront cost of the trucks are 50% more than their diesel equivalents, expected payback is two to three years with fuel savings of £15,000 to £20,000 a year depending on mileage.

The vehicles should operate for at least five more years, generating overall lifetime savings of £75,000 to £100,000 compared with diesel equivalents. ‘We can run five gas trucks for the same emissions as one diesel lorry,’ says Justin Laney, general manager of central transport for the John Lewis Partnership, which incorporates Waitrose. ‘We will be able to make deliveries to our stores without having to refuel away from base.’

Biomethane supplier CNG Fuels has been working with Waitrose on the initiative, and has invested in a fuelling station outside the retailer’s Leyland depot in Lancashire. ‘Leyland is just one of four stations that will be put in,’ says chief executive Philip Fjeld. ‘We will install another station for Waitrose next year and then between 2019-2020 we will put in another two. That will then cover all of their truck demand [which is] 500-plus trucks.’

Significantly, the refuelling station will have public access, enabling other fleet operators to benefit from them. ‘The station at Leyland has capacity to refuel between 500 and 1000 trucks per day,’ says Fjeld. ‘If Waitrose were our only customer we wouldn’t be even remotely close to full utilisation. Waitrose is an anchor customer that can get us off the ground and underpin a certain percentage of usage, but the ultimate business case for us relies heavily on other users coming in over time and using the station.’

Going further

The biomethane CNG Fuels supplies is from food waste, but Fjeld says other waste streams, such as sewage sludge, can be used in future. The company has ambitious plans for growth. ‘From 2018, we are looking to roll out between four to six stations a year,’ he says.

With Waitrose, the proof of concept is now there to scale up supply of CNG biomethane as a clean, cost-effective alternative to diesel, he adds: ‘There are a lot of other companies now taking a very serious look at this and are ordering trucks for delivery later this year.’

Meanwhile, other freight operators, such as Howard Tenens, have introduced dual-fuel vehicles into their HGV fleets. The logistics firm has invested about £650,000 in conversions and operates 36 dual-fuel vehicles that used a combination of gas and diesel – 28% of its fleet.

‘At present we only use CNG, but we’ve always seen that as a stepping stone to biomethane,’ says Anna Rickard, environment manager at Howard Tenens. ‘By operating dual fuel vehicles in our fleet we have reduced our CO2 emissions by nearly 750 tonnes per annum, which equates to a reduction in fleet emissions of 6.5% per annum.’

The company is due to trial the UK’s first pair of dedicated biomethane 26-tonne rigid vehicles as part of the government’s low-emission freight strategy. Meanwhile, technology provider Advanced Plasma Power is building a prototype waste-to-biomethane plant to supply the biogas and should be on-stream early next year. ‘For vehicles that run 100% on gas, this will achieve a reduction in well-to-wheel CO2 emissions per vehicle of about 75% compared with diesel,’ says Rickard.

She adds that the rising price of diesel is helping to strengthen the business case for gas trucks – the company has invested more than £1m in gas refuelling infrastructure so far. Displacing diesel with gas also results in fewer air pollutant emissions, an important consideration given the wider policy push for improving air quality and the rise of city clean air zones.

Previously Howard Tenens has participated in several low-carbon truck trials, part-funded by Innovate UK, which involved extensive emissions testing. ‘Understanding the benefits of dual-fuel vehicles was an important aspect of the trials,’ says Rickard. ‘We tested five vehicle types over the same route, first when the vehicle was running on diesel only and then when it was running on dual fuel. The tests showed that the NOx emissions averaged 16% lower when the vehicles were running on dual fuel.’

Zero-risk option

Richard Carter, sustainability and finance lead at drinks business Adnams, regards dual fuel as a ‘zero-risk approach’ to establishing biomethane trucks in the UK. The Suffolk-based brewer has been working with fuel technology specialist Diesel Dynamics to convert one of its 18-tonne trucks to run on biomethane using gas produced by Adnams’ on-site anaerobic digester (through the grid).

Trials of the dual-fuel HGV, which also runs on diesel, have returned some encouraging results. Based on the first six months of data, Carter says cost savings are more than 30%. ‘We’ve saved 9% of the CO2 emissions, which we are very pleased with. But best of all the NOx emissions are down by 63%. So this vehicle lets us reduce our cost, carbon and pollution.’

This is important as NOx emissions are fuelling concern about poor air pollution in urban areas.

Adnams’ plan is to implement a full-scale solution. ‘Clearly there’s a lot of work to do before we implement that, but it is very much our intention,’ says Carter. ‘It’s looking increasingly likely that we will adopt the same system on a second vehicle before we roll out it across the fleet.’ He adds that going down the dual-fuel route makes more sense for Adnams because the vehicles it runs now can be converted. ‘That makes the business case significantly more appealing. It is fair to say that the world will be stuck with diesel vehicles for some time to come, so finding a solution that can be retrofitted is critically important.’

Electric power

For some, electric-powered trucks represent the holy grail, despite the technical challenges involved with battery capacity and concerns over embodied carbon. One company making headway with electric fleets is UPS, albeit with smaller HGVs. In the UK, it has converted 52 of its 7.5-tonne trucks from diesel to pure electric (pure EVs).

‘It’s quite possible with a pure EV to conduct about a quarter of all of the duty cycles that we operate on a daily basis with vehicles of that type in the UK,’ says Peter Harris, UPS’s director of sustainability for Europe. ‘In the UK we’ve been focusing on London – we’re lucky in that our operating depot in Kentish Town is relatively close to the city centre so, in theory, just about every vehicle we operate from that depot – there are 170 of them – could be electric.’

He says the biggest challenge is in securing enough power to charge the vehicles: ‘Even when we only had ten pure EVs in London a few years ago we were already at the limit of our building’s power availability overnight for recharging. We took the decision to invest in a major power upgrade and that increased our capacity from ten [EVs] to 63, but we’re approaching that limit again.’

Keen to find a solution, UPS has formed a consortium with two companies, UK Power Networks and Cross River Partnership, and secured government funding to deploy a smart grid system to find a way to more efficiently connect its vehicles to the grid so it can minimise, or even eliminate, the need for further conventional capacity upgrades. ‘Primarily this is about being able to access the power that is available at certain times of the night when other requirements within the building are lower,’ says Harris.

If the two-year project is successful, it will be a key enabler for the company to electrify its other fleets throughout the UK and beyond, he adds. ‘We think we’re the first ones to deploy this type of fleet application of smart grid. We’re not aware of any others, certainly at this scale.’

Extending the range

For the three-quarters of duty cycles that cannot be covered by pure EVs, UPS is exploring the use of range extended electric vehicles (E-REVs). In a venture with E-REV specialist Tevva, it has built an E-REVprototype that has been operating for about a year. Further government funding has been secured to build 15 more E-REVs, which UPS will deploy later this year in Birmingham and Southampton – both of which are proposed clean air zone sites.

Harris says: ‘We serve Birmingham from Tamworth and we can’t get from Tamworth into Birmingham, do a day’s work and come back again using a pure EV. The battery range isn’t enough. But with an E-REV, you can run from Tamworth to the outskirts of Birmingham with the range extender operating, keeping the battery at full capacity. The extender would switch off at Birmingham city limits and the vehicle would operate all day as a zero-emissions vehicle. To get home, the range extender would kick in again.’

According to Harris, lifecycle impact savings for E-REVs have been shown to be around 30% well-to-wheel, similar to a pure EV. For UPS’s larger HGV fleet, he says electrification is not yet feasible: ‘For the interim period, and I think we’re talking several decades realistically, we think the answer lies with gas.’

Globally UPS has around 19,000 tractor units, 20% of which are running on both CNG and liquefied natural gas (LNG) – within this, renewable gas accounts for around 10% of use, mainly in the US. The situation is more complicated throughout Europe where the number of pure gas-powered HGVs is much lower.

In the UK, UPS has invested in 19 dual-fuel trucks, representing about 10% of its UK HGV fleet. Initially the vehicles ran on LNG biomethane but, due to a lack of government incentives, this is no longer feasible and UPS has reverted to conventional LNG.

But Harris is optimistic that the tide will turn for LNG biomethane: ‘There is a great opportunity here. When you think about the options you have for an HGV on the motorway, this is probably one of the single best strategic uses of renewable natural gas.’