The Non-Exhaust Particulate Emissions Impact of EURO VI to Battery Electric Bus Fleet Transitions

There is already strong evidence that non-exhaust emissions (NEEs) are a significant source of transport-related particulates, and an expectation that this will increase as we transition from 13 conventional to heavier alternative technology vehicles. (1) Therefore, we need to ensure that our existing commitment to zero (at tailpipe) emissions is complemented by an active effort to mitigate any unintended consequences for NEEs. (2)

This work, led by FirstBus, and funded by the TRANSITION Clean Air Network funded by the Natural Environment Research Council within the UKRI Clean Air Programme (3), uses the EURO VI-to-Battery Electric Bus transition as a case study to explore options to: (a) improve inventorying information available to fleet managers considering fleet upgrade options; and, (b) gather evidence on the potential divergence between regulatory metrics, conventional emission factors, inventory model predictions and the real-world outcomes as we migrate to what need to be significantly cleaner technologies.