SCR retrofit government support to end
Government funding for the retrofit of selective catalytic reduction (SCR) technology is being brought to an end.
Government funding for bus retrofits was paused in April 2023 after research suggested that real-world emission reductions from retrofitted buses were lower than expected.
Between 2017 and 2019, £64 million was allocated to the clean bus technology fund for bus upgrades and retrofits of this kind of technology. A further £31 million was provided to local authorities in the government’s NO2 programme. Approximately 9,000 buses in England have been retrofitted with CVRAS-accredited SCR technology.
However, in 2021 the government was made aware of new evidence from Scotland suggesting that real-world emission reductions from retrofitted buses were lower than expected. In 2022 a roadside monitoring campaign was commissioned to measure NOX emissions from retrofitted buses in three areas in England which reported in early 2023. The findings were similar to those in Scotland. This lead to the pause of support in April 2023.
Further research into this was conducted, resulting in a report that concludes that real-world performance of bus retrofit SCR technology is highly variable, achieving 80% to 90% NOX reductions in some cases, but having a minimal effect in others. There is an average 11% reduction in NOX emissions overall from retrofitted buses compared to non-retrofitted Euro V buses, which is significantly lower than the 80% reduction anticipated.
“Based on these findings, I am announcing today a permanent end to further government funding for retrofit and the closure of the clean vehicle retrofit accreditation scheme to further accreditations” – Transport Secretary, Louise Haigh MP
A written statement to Parliament from Transport Secretary, Louise Haigh MP, said: “The research shows that a number of contributing factors can lead to poor performance, including incorrect functioning of retrofit systems, the condition of bus engines and low catalyst operating temperatures. Based on these findings, I am announcing today a permanent end to further government funding for retrofit and the closure of the clean vehicle retrofit accreditation scheme to further accreditations.”
Moving forward, the government aims to work with bus operators and retrofit suppliers to encourage a step change in monitoring and maintenance of retrofit systems in an attempt to get the best possible performance from the retrofitted buses currently in service. This will include ensuring that buses are providing live data showing retrofit performance so that operators and depots can prioritise and target essential maintenance on the poorest performing buses. Providing this data will be a condition of the buses remaining on the list of CVRAS-accredited vehicles.
Commenting on the Bus Retrofit Performance Report, Keith McNally, Operations Director, Confederation of Passenger Transport, said: “CPT remains committed to working closely with all stakeholders, including government bodies and operators, to ensure that the investments made in retrofitting technology yield the best possible results.
“Both the government and operators have invested in this technology in good faith, and CPT will continue to advocate for solutions that maximise the environmental benefits while ensuring operators can achieve optimal performance from retrofitted buses.”