Battery electric trucks follow decarbonization route

An International Council on Clean Transportation (ICCT) study comparing the lifecycle greenhouse gas (GHG) emissions of European heavy goods vehicles puts battery electric trucks at the top of its cleantech options. And a key finding of the report – published this month – is that fuel use dominates the emissions landscape. Over their lifetime, HGVs can travel over 1 million kilometers. And trucks (and buses) account for more than a quarter of Europe’s transport emissions despite representing only 2% of vehicles on the road. The numbers indicate that while there’s still much to be gained from encouraging car owners to switch from fossil-fuel to battery-powered models, transportation emissions are geared for rapid improvement.

Currently, diesel powertrains dominate (96.3% of trucks and 93.5% of buses, based on 2022 data). And just 1% of 2021 new heavy-duty vehicle registrations corresponded to zero-emission alternatives. Yet, the ICCT report finds that battery electric trucks bought today would offer GHG emission savings of 63% compared with diesel-powered vehicles. And these calculations are based on the current electricity grid mix, which is far from being fully renewable. The contribution of battery electric trucks, and other heavy-duty vehicles such as buses, will grow further as more wind, solar, hydro, and other clean energy generation sources are added to Europe’s electricity infrastructure.

What about biofuel?

Longer term, the EU’s electricity grid is becoming greener – compared with energy production in the 1990s, today’s power supply is 54% less GHG intensive. If all-renewable energy sources were used to charge battery electric trucks then GHG emissions savings could be as high as 92%. Diesel can be blended with biofuel to soften its emissions impact, but the report finds that the percentage of the bio-component is low (around 7% by volume) and points out that the EU has a limited number of sustainable sources. Adding biofuel to diesel won’t solve the problem of transport emissions on its own. And there will need to be an increase in the use of battery electric trucks and buses. EU regulations call for fleet-wide average CO2 emission reduction targets of 15% by 2025 and 30% by 2030.

Fossil fuel fans are quick to mention that the construction of battery-powered vehicles can be much more energy intensive than models featuring internal combustion engines. But electric vehicles quickly make up ground during use thanks to reduced road emissions, especially when the energy sources used to recharge battery packs are renewable. “The greatest climate impact produced by trucks and buses over their whole life comes from the use or fuel consumption phase, not from the extraction of raw materials, construction, or maintenance,” write the study’s authors.

The report also considers hydrogen as a fuel source for vehicles. But GHG savings from hydrogen-powered trucks don’t get close to batteries until hydrogen can be sourced renewably. Progress is being made in that area – for example, in Toulouse, France, where green hydrogen-powered airport buses are pathfinding uses in aviation. The buses are supported by a 1 MW hydrolyzer that can produce 400 kg of green hydrogen per day by splitting water using clean energy. And the idea is that the infrastructure could be scaled up to provide renewable fuel for light aircraft once designs for hydrogen-powered aviation engines have been validated.

Another option is so-called electrofuels (e-fuels) or synthetic fuels. Hydrogen is combined with CO2 to produce synthetic hydrocarbons such as methanol or ethanol, which could then be used in vehicles. The popular motor racing series, Formula 1, has pledged to use 100% sustainable fuel from 2026. And it’s project partner ARAMCO will be producing the synthetic fuel at two industrial facilities – one located in the Middle East and the other based in Spain. A big benefit of e-fuels is that they can – in principle – be used as a drop-in replacement for gasoline or other fossil-fuel derivatives. But the flip side is that synthetic fuels can be energy intensive to produce. A citation in the ICCT report flags that the required amount of electricity required to make electrofuels is 6x higher compared with using the energy directly in battery electric vehicles such as cars, trucks, or buses.

Supply constraints

But there are still road bumps when it comes to battery electric vehicles. Haulage firms are concerned by the initial cost of battery electric trucks compared with diesel-powered versions. And there are hold-ups in availability. Tesla announced its battery-powered semi-truck – the motorized half of a heavy-duty tractor and trailer combination – in 2017. Five years later, the US-headquartered electric vehicle maverick is reportedly shipping its first battery electric trucks to customers. Battery-powered trucks require much larger numbers of battery cells compared with electric vehicles, adding to the demand for lithium-ion materials, which are already supply constrained globally.

Other manufacturers of battery electric trucks for haulage applications include Daimler Trucks, Lordstown Motors, Proterra, Nikola Motors, and Rivian. China, which leads the world in battery production, is also home to automotive firms offering battery electric trucks, such as BYD. Whether battery electric trucks represent the future of transporting goods by road, or provide a stop-gap until the widespread rollout of green hydrogen infrastructure, remains to be seen. But focusing first on vehicles that spend much of their lifetime on the road, rather than parked up on the drive, or in the street, will ramp up the capacity of electric power to reduce transport emissions.