Transport and air pollution Air pollution: what is the scale of the problem and what can be done about it? Dr Marc Stettler m.stettler@imperial.ac.uk | @TransEnvLab_IC Centre for Transport Studies | Department of Civil and Environmental Engineering Imperial College London 20th April 2017

London’s NOx emissions by sector Katie King (Aether), APRIL meeting, 14th October 2016.

A transport impact identity… Car sharing Teleconferencing Optimised logistics Activity ↔ Economy Cleaner engines (better emissions control) Alternative powertrains (e.g. EV, hybrid) AQ impact=Activity× Energy Activity × Emissions Energy × Impact Emissions When I think about AQ impacts of transport and when I try to communicate the issues to my students for the first time, I like to start with a simple identity equation. Some of you may have seen something similar before. Essentially, the AQ impact is proportional to how much transport activity there is, how much energy is used per unit of activity, the emissions per unit of energy and a very simplified impact factor, which is determined by how the emissions are dispersed into the atmosphere and how close they are to the population. So in simplified terms, we can reduce the impact of transport by reducing one of these factors. For activity… For energy intensity… For emissions factors… For impact… So today I’m highlighting 3 priorities as I see it, in roughly order of timescale, so from short to longer term priorities. More efficient engines Light-weighting Reduced drag Low rolling resistance tyres How close are people to the source of emissions?

Caution: Air quality (NO2) in London NO2 concentrations have not improved even though vehicle emissions standards have become stricter… EURO 3 EURO 4 EURO 5 EURO 6

Priority 1: Real-world emissions compliance Real-world diesel emissions ~5 times (average) higher than Euro 6 standard European Commission Real-Driving Emissions limits Euro 6 ×2.1 (0.168 g/km) from Sep 2017 Euro 6 ×1.5 (0.12 g/km) from 2020 Independent, in-service testing required O’Driscoll et al. 2016. Atmospheric Environment 145: 81–91. http://www.sciencedirect.com/science/article/pii/S135223101630721X

Consumer information www.equaindex.com Here is an example of the information that’s open for all of you to look at for the different vehicles tested by Emissions Analytics www.equaindex.com

Priority 2: (Ultra) low emissions vehicles Range of options to suit passenger/commercial vehicles Low (potentially zero) tailpipe emissions EVs make up <2% of new car sales in UK Hybrid EVs (HEV) Plug-in hybrid EVs (PHEV) Battery EV (BEV) Advanced IC engines Geofencing Range-extended EVs Hydrogen fuel cell EVs That is ultra low emissions vehicles. At these early stages, we’re seeing a very large range of technology solutions to meet the specific requirements of different customer needs. In the medium term, I expect they will all have some part to play. These technologies drastically reduce tailpipe emissions, some to zero. Geofencing is when there is an automatic switch in a vehicle with energy storage to say that the battery power must be used and the range extender engine can be switched on. This could be used around air quality hotspots or in ulta-ultra-low emissions zones. Natural gas/ biomethane Zero tailpipe emissions

Opportunity: Reduce peak engine load O’Driscoll et al. 2016. Atmospheric Environment 145: 81–91. http://www.sciencedirect.com/science/article/pii/S135223101630721X

Hybrid trucks HGVs account for ~24% of London NOx emissions Use electric power to provide ‘boost’ during acceleration http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_14-2-2017-11-30-58

Driving behaviour [TRAFFIC SUMULATION VIDEO] Smoother ‘eco-driving’ benefits Fuel consumption: up to ~10% NOx emissions: up to 25-50%

Thank you. Dr Marc Stettler m.stettler@imperial.ac.uk | @TransEnvLab_IC Centre for Transport Studies | Department of Civil and Environmental Engineering Imperial College London 20th April 2017