LNG trucks: a dangerous dead-end for the climate

The gas industry claims that trucks powered by liquified natural gas (LNG) could reduce greenhouse gas (GHG) emissions and air pollutants compared to conventional diesel trucks, whether they run on fossil natural gas or renewable methane.

But the results of T&E’s testing are sobering: LNG trucks are no better for the climate than diesel trucks, neither in terms of greenhouse gases nor air pollutants. Over a 100-year global warming potential (GWP), the LNG truck reduced well-to-wheel GHGs only by 7.5% compared to the tested diesel truck. When looking at a 20-year GWP time frame, the LNG truck caused higher emissions than the diesel truck, resulting in 13.4% higher GHGs. A previous study commissioned by the German Environment Agency found similar results.

Even when looking at tailpipe CO2 only does not change the picture: When the International Council on Clean Transportation analysed the official monitoring and reporting data of new trucks, it found that Iveco’s gas trucks are performing even worse than Scania’s best-performing diesel trucks.

And contrary to the manufacturer’s claims that LNG trucks would reduce particle mass emissions, our real-world testing also showed that both particle mass and particle number emissions can be higher than those from diesel trucks. The tested LNG truck emitted particularly large amounts of ultrafine particles which are increasingly considered as the most harmful to human health and currently not regulated under the Euro VI pollution standard.

The findings are in stark contrast to the industry’s claims that LNG is a viable ‘bridge technology’ which could reduce GHGs from trucks on the road immediately, and power the fleet with renewable methane in the future.

The problem is that neither sustainable biomethane nor synthetic e-methane will be scalable or affordable enough to decarbonise trucking. Advanced biomethane feedstocks are only available in limited quantities. Our analysis shows that, even with extremely high subsidies – up to six times the retail price of fossil LNG – the biomethane potential in the six biggest European countries could only meet 4% to 28% of the expected energy consumption from trucks by 2050.

Exploiting this potential would not only cost the German taxpayer dearly, it would also mean that no biomethane would be left for the power, buildings and industry sectors where its abatement potential is badly needed.

Let’s take the German example: No German LNG refuelling station is currently supplying liquefied biomethane to LNG trucks. And a mere 17% of today’s biomethane production in Germany – which is mostly converted to electricity and heat – is sourced from sustainable wastes and residues.

There are no large-scale gas liquefaction plants in Europe today. The first ones will probably be able to deliver larger volumes of bio-LNG to the European market by 2023. That means that the vast majority of LNG for trucks will continue to be imported from overseas for the foreseeable future, including from the U.S. and Russia, two countries which struggle with high levels of methane leakage along the fuel supply chain.

When it comes to e-methane produced from green electricity and CO2 from direct air-capture, no large-scale quantities would be available until 2030, and whatever volume could be delivered to the market in the 2030s would come too late to decarbonise trucking and be significantly more expensive from a total cost of ownership perspective than the zero-emission alternatives.

Continuing the investment into vehicles and LNG refuelling infrastructure would therefore lead to stranded assets and create a fossil fuel lock-in due to the lack of renewable alternatives. As long as some truck manufacturers, hauliers and infrastructure operators continue to invest in this technology, they will have a vested interest to protect those investments. Since there will not be enough renewable methane available at competitive cost, the industry would instead (need to) rely on fossil gas in order to meet the fuel demand from a growing LNG truck fleet.

Spending time and money on a technology which can deliver little, if any climate benefit and can actually increase emissions over the next two decades is not compatible with climate neutrality. Instead, Europe should end its harmful subsidies for gas trucks and focus on zero-emission technologies.

First published in Tagesspiegel Background Verkehr & Smart Mobility on 19 November 2021 [LINK].