Charging Infrastructure Optimisation for Electric Taxis
Develop an optimal charging structure for a fully electrified taxi fleet in Singapore and to increase the occupancy rate of taxis. Taxis are an essential part of public transport in Singapore. Even though they account for just 3 % of Singapore’s vehicle population, their share of CO2 emissions of all road transport in Singapore is 15 %. Hence, electrifying taxis is quite a significant contribution to emission reduction of road transport. We have been working on this project with a Singaporean taxi company since 2014.
Approach and Methodology
In order to determine an optimal charging infrastructure for electric taxis, a realistic simulation model has to be developed first. For this purpose, we equipped 50 taxis in Singapore with GPS loggers and recorded their trajectories over a period of six months in a temporal resolution of 1 data point per second. This gave us a very clear picture of where the taxis were going and when. The above image shows an occurrence map, i.e. locations taxis visit most frequently, for Munich, Germany, where a similar study was carried out by the Technical University of Munich. Together with booking data provided by the company, we were able to implement a simulation of conventional taxis and eventually electric taxis which does not only include taxis’ trajectories, but also the types of trips, status, and even revenue. Currently, we are finalising the simulation for the forthcoming optimisation of the charging infrastructure.
The project was successfully completed in 2017. We performed a profound analysis of the given taxi fleet and implemented a simulation.
At the end of the project, we proposed how to increase the occupancy rate of taxis and how to move from today’s taxi operation based on mainly diesel vehicles to electric vehicles.
A higher occupancy rate means that fewer taxis drive around without passengers. This reduces travel time and hence fuel consumption, emissions and traffic jams. Electric taxi operation energy demand and cost even more.