Anthropogenic heat from road transport

In road transportation, there are almost no waste products or chemical absorption processes and it can be assumed that all the energy consumed by the road transport sector is eventually transformed into heat. As vehicles move, they actively produce heat that contributes to the increase of urban temperatures. Apart from its active contribution, road transportation also passively releases heat that is stored by roads as a consequence of prolonged exposure to solar radiation. Road traffic is believed to be a significant contributor to the Urban Heat Island (UHI) effect.

external page Dr Jordan Ivanchev and Dr Jimeno Fonseca from the external page Cooling Singapore team studied the active component of traffic anthropogenic heat in this report. Their work aimed to evaluate the potential for heat mitigation with the complete electrification and automation of the road transport sector in Singapore.

In the report, the researchers presented a case study examining the spatio-temporal profile of heat emissions due to road transport for a typical day in Singapore. They then calibrated and validated a city-scale agent based simulation model, which was used to analyse future electrification and automation scenarios. Furthermore, they also evaluated the temporal energy demand associated with the electrification of transport and assessed the heat released for the production of the energy in demand. Lastly, they studied how the presence of autonomous vehicles might affect the amount of heat produced by road transit.

The results from the study showed a six-fold decrease of the energy usage of the road transport sector in the scenario with the complete electrification of all vehicle classes. However, vehicle electrification causes an increase in indirect heat generated due to electricity generation at power plants. Summing up the direct and indirect heat, the researchers saw that an electrified road transport system brings a three-fold decrease in heat generation.

The study further showed that autonomous mobility significantly reduces the average commute time from 23 minutes to 14 minutes while the energy usage levels are almost identical to the full electrification scenario. It was also shown that the lorries and vans vehicle class is the biggest contributor of heat and that the peak in terms of heat generation in a day coincides with the rush hour traffic occurrences.

For full details, read the report external page "Anthropogenic Heat Due to Road Transport: A Mesoscopic Assessment and Mitigation Potential for the City of Singapore" published by the Singapore-​ETH Centre.