LowCVP identifies ‘quick win” technology to tackle air pollution

LowCVP has identified and assessed vehicle retrofit technologies capable of making a “near-term impact” on air pollution in Britain.

This comes after working with the government’s Joint Air Quality Unit (JAQU).

Using LowCVP’s analysis, a new £30 million government grant scheme is now open to local authorities in England and Wales who are looking to implement accredited, rapid, cost-effective and reliable emissions-reduction retrofit programmes in bus fleets.

Published today, 27 September, LowCVP’s Evaluation Report on the previous Clean Vehicle Technology Fund (CVTF) and Clean Bus Technology Fund (CBTF) Programmes assessed a range of retrofit technologies tested through these public grant schemes that have been run over the last five years. The outputs have helped to shape a robust and reliable method for assessing competing retrofit technologies and helping authorities and operators to identify effective technologies.

The LowCVP, working with the Energy Saving Trust (EST), has developed the findings from the Evaluation Report to produce the Clean Vehicle Retrofit Accreditation Scheme (CVRAS), which will enable the existing fleet of urban vehicles (initially buses, but extending rapidly to a wide range of vehicles) to be fitted with proven emissions-control solutions.

The Evaluation Report shows how it is critical for any vehicle operators and authorities to get independent and reliable emissions data or certification, before committing to any retrofit programme, and to ensure the technology is both effective and reliable in-service.

The CBTF (2013/2015) and CVTF (2014) programmes were introduced by the Department of Transport (DfT) to help reduce NOx emissions from diesel vehicles in cities experiencing poor air quality. The funding facilitated trials which involved retrofitting 2,137 diesel vehicles using a variety of NOx emission abatement technologies.

JAQU commissioned and funded the LowCVP to undertake an evaluation of the CVTF and CBTF programmes, with the objective of determining the efficacy of different retrofit technologies in terms of reducing tailpipe NOx emissions and evaluating in-service performance.

In addition, the study assessed the impacts of the technologies on other air pollutants and greenhouse gas emissions. It covered twenty-five local authority projects, five vehicle types and seven technologies including exhaust after-treatment such as selective catalytic reduction (SCR), fuel saving systems such as flywheel hybrids and engine conversions (such as the introduction of electric powertrains).

The LowCVP analysed a range of vehicle testing data, before and after retrofit equipment was fitted and when in service.

The key findings of the Evaluation Report were: the highest NOx emission reductions (80 per cent to 100 per cent) were seen for retrofit SCR after-treatment and diesel bus engine conversion to use an electric powertrain; moderate NOx emission reductions (25 per cent to 29 per cent) were achieved by retrofit thermal management and flywheel hybrid technologies; and low NOx emission reductions (3 per cent to 6 per cent) were achieved by mild hybrid, hybrid assist, and dual fuel CNG conversions.

SCR retrofit, as well as showing the highest emissions reduction also demonstrated excellent conformity with testing undertaken six months and two years after the initial fitting. The technology achieved high levels of NO2 emissions reduction (>80 per cent). The majority of retrofit SCR systems were fitted with particle filters, also resulting in high reductions (>75 per cent) in particulate (PM) emissions.

LowCVP’s head of projects, Gloria Esposito, said: “The LowCVP work has highlighted the need for robust and independent vehicle emission testing to demonstrate the performance of retrofit technologies in terms of both air pollutants and greenhouse gas emissions.

“The Clean Vehicle Retrofit Accreditation Scheme builds upon our earlier work, enabling technology providers and vehicle users to focus on a nationally recognised independent system of equipment quality, durability and performance.

“LowCVP’s work in developing retrofit technology accreditation over a number of years provides one important part of the solution to tackling the urgent problem of cutting air pollution in our cities.”