Emissions testing of gas-powered commercial vehicles

At the start of this year, a report prepared by the Low Carbon Vehicle Partnership, on behalf of the Department of Transport, published the results of tests to measure the greenhouse gas and air pollutant emission performance of various gas-powered HGVs.

Whilst freight transport is absolutely vital to economic growth, it has significant environmental impacts. Heavy goods vehicles are currently estimated to account for around 16% of UK greenhouse gas emissions from road transport and around 21% of road transport NOx emissions, while making up just 5% of vehicle miles.

With increased pressure being placed on the transport sector to reduce their carbon footprint and help to reduce greenhouse gas emissions, new alternative fuel sources are being watched with interest.

Heavy goods vehicles are currently estimated to account for around 16% of UK greenhouse gas emissions

The truck trial which ran between 2012 and 2016 (and largely tested Euro V trucks) revealed that  Nitrous Oxide (commonly known as laughing gas) emissions could add 5 to 10% to the Greenhouse Gas impact of a bus. Additionally, for dedicated natural gas vehicles there were mixed Greenhouse Gas results — with at best savings of 5% but at worst some 15% higher than the diesel comparator. Similarly, for the current-generation dual-fuel vehicles operating on diesel and natural   gas, levels of methane slip were found to be substantial under all test cycles contributing towards Greenhouse Gas increases of around 10-35%.

However, LPG retrofit conversions — produced LPG as an unburnt fuel rather than methane — and subsequently achieved average Greenhouse Gas savings of 2%. At a time when there is large amounts of evidence to suggest that more needs to be done to improve air quality, this presents a real opportunity for large HGV vehicles to help to help contribute towards this drive for cleaner air.

Previously part of the solution to reduce the environmental impact of vehicles was to switch to diesel, as it has lower carbon emissions. However, its particulate matter and nitrogen oxides (NOx) emissions are high and result in localised, very poor air quality.

LPG is seen as providing a solution to this — it is a quick and low cost way to address air quality issues — with 99% less particulate matter and 80% less NOx being emitted than an average diesel engine. In the Spring of this year, we have bioLPG landing in Britain for the first time. LPG provider Calor considers that this will mean that, not only can vehicles have much lower emissions of particulates and NOx, but also a much lower carbon footprint too, helping to tackle the global challenge of climate change.

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