Stove Industry Alliance responds to wood burning stove and HGV emissions comparison
- In the time taken to produce 1GJ (around 14 days’ worth) of heat to a home from a wood burning stove, at typical usage rates an HGV will have emitted 538g of PM2.5, over 7 tonnes of CO2e and similar amounts of NOx as the stove*.
- A Euro 6 HGV produces 13 times more PM2.5 emissions than an Ecodesign wood burning stove over the course of 1 week’s real-world use.
- In 1 hour an Ecodesign stove will emit 0.72g of PM2.5. In that time a Euro 6 HGV will have produced up to 4.3g of PM2.5.
It has been widely claimed that a modern Ecodesign stove produces the same number of particulate emissions as 750 modern HGVs.
The source of the original HGV figure is a report by the European Environmental Bureaucalled Where there’s fire, there’s smoke. This report looks at the amount of PM2.5 emissions given off by generating a GJ of heat in a stove compared to the amount generated by creating a GJ of power in an HGV.
The resulting claims are based on simplistic calculations using permitted rates of emission and do not consider either real world use or non-exhaust emissions. Furthermore, these permitted emissions rates rely on vastly differing measurement protocols and techniques. It should also be noted that there are several unreferenced assumptions, and the report does not appear to have been independently peer reviewed.
James Verlaque, technical manager of the Stove Industry Alliance, commented: “We must be very careful comparing two completely dissimilar things, and this particular comparison is highly misleading – like comparing apples to oranges. Comparing the emission rates between sources only tells part of the story. It is important to look at the impact of real-world use, and that paints a very different picture.”
According to Defra’s 2020 report, Burning in UK Homes & Gardens, by Kantar, on average, stove users light their appliance for 29 hours a week (between 3.7 and 4.5 hours a day) during the winter. Under current driver’s hours rules an HGV can be driven by the same driver for 9 hours a day. This is a much longer daily run time and is not subject to the seasonality of wood burning stove use – HGVs operate 24/7 up to 365 days a year. Over the course of a week of typical use an Ecodesign stove will emit 20.16g of PM2.5, whereas a Euro 6 HGV will emit 271g of PM2.5. That’s over 13 times the amount of the stove*. Using HGVs as a comparison is therefore deeply flawed.
It should also be noted that emissions from wood burning stoves are typically at 5 metres plus above the ground, whereas HGVs emit at near ground level. There is wide agreement in the scientific press that non-exhaust emissions of particulate matter from vehicles are greater than exhaust emissions, with AQEG estimating that this could be as much as double the emission rate from the exhaust.
Andy Hill, chair of the Stove Industry Alliance, added: “In order to tackle poor air quality we must be sure to fully understand the impact of all sources of emissions and not be selective. It’s simply not helpful, and is indeed misleading, to point the finger at one source or partial emissions from one source, without looking at all sources with the same degree of focus. In the case of the comparison presented by the EEB, no consideration has been given as to how stoves and HGVs are used in real life or the height at which they vent. Neither have the non-exhaust emissions of the HGV been factored into the comparison. This further analysis clearly shows that the 1:750 claim is misleading and fundamentally flawed by failing to take account of the real-world use of wood burning stoves compared to HGVs.”
*Figures have been independently verified.