Pathways to achieve future CO2 emission reduction targets for bus transit networks

Apart from electric vehicles, emissions targets for 2025 and 2030 in the heavy-duty transportation sector could be achieved with hybrid powertrains. Moreover, alternatives such as the use of synthetic or e-fuels may also offer a feasible path for transport decarbonization. This work explores different pathways to reduce CO2 emissions considering the city of Valencia as a case study. The 10 most used bus lines operating in the city are evaluated using their GPS based vehicle speed information with 0D GT Suite simulations. First, the hybridization level for the share of buses was varied from 0 to 100% and the number of different bus types operating in each line was optimised for minimum CO2. Next, the battery and E-motor sizing is optimised for each bus line. Further, an assessment was done assuming 100% electrified fleet, with the 2030 and 2050 electricity generation CO2 footprint projections. Moreover, the potential of e-fuels in the current fleet is also evaluated. The results show that to meet the 2050 target, 100% electrified fleet (with 2050 electricity mix) as well as using e-fuels (generated from renewable sources) in the current fleet are feasible options. However, the e-fuel pathway is more economical than 100% electric fleet. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

This study explores different pathways to reduce CO2 emissions in urban public transportation systems through hybrid powertrains and alternative solutions such as e-fuels, obtaining valuable findings in the case study of Valencia.