Secondary engines for transport refrigeration

MQT on 2019-06-20
Session date: 
June 20, 2019
Question By: 
Caroline Russell
City Hall Greens
Asked Of: 
The Mayor


According to the Transport for London (TfL) study on non-exhaust vehicular emissions, Auxiliary temperature reduction units in the Greater London area, published in March 2018, 3,500 refrigerated delivery trucks on London roads have secondary engines that use red diesel, which emit 4.5 times more NOx and 30 times more PM than tailpipe diesel emissions. What specific actions have you taken to address this?


Secondary engines for transport refrigeration

Secondary engines for transport refrigeration

Answered By: 
The Mayor

TfL remains actively involved in cutting edge research to develop a robust, representative and cost-effective methodology for measuring the energy consumption and emissions performance of refrigerated commercial vehicles. TfL, via the LoCITY ( network, is also working directly with operators to understand current barriers to deployment, and to promote the use of cleaner auxiliary power units where possible. 

My recently launched Freight & Servicing Action Plan (March 2019) commits TfL to working with boroughs and businesses to transform how deliveries are made in the capital. A reduction in the number of vehicles entering the Greater London Area will help address the impact auxiliary temperature reduction units are having on air quality. Increased efficiency can be achieved through the use of pvc strip curtains across doorways, certified driver training and the mandated use of cleaner diesel, which will require policy changes at a national level.  For that reason, as I state in my London Environment Strategy, I will continue to lobby for the appropriate tax treatment of rebated ‘red’ diesel, so that a switch to cleaner or alternative fuel is financially incentivised.