Amid heightened concerns over Karachi’s severe air pollution, the Asian Development Bank (ADB) says E-buses are not a suitable solution for the city’s Bus Rapid Transit (BRT) systems mainly due to its unstable electric system.
As an alternative, using biomethane buses was assessed with Karachi having a very large potential to produce biomethane derived from cattle waste dumped currently in the sea in the larger urban zone of the city. This solution is not only much cheaper than e-buses (with a TCO comparable to diesel units), but also technically simpler than electric units and with a larger GHG impact due to not having upstream emissions from electricity production, suggested the ADB.
ADB, in its study-E-Mobility Options for ADB Developing Member Countries, said apart from reduced customs duties, Pakistan has no specific incentives for Electric Vehicles (EVs). The impact of an EV on local pollution levels is high due to the high sulfur contents of fuels and the low vehicle emission standards applied.
Karachi is one of the most densely populated cities in the world, Karachi is consistently ranked as one of the world’s most unlivable cities. Traffic congestion and induced air and noise pollution play a major role in these poor rankings. Karachi’s current transportation system includes informal paratransit vehicles and approximately 4,000 privately owned buses.
The city is in the process of constructing a bus rapid transit system with multiple open bus lanes operated with 9-m, 12-m, and 18-m buses and linked together with last-mile connectivity services.
ADB is financing the BRT red-line which shall start operations in 2020 with around 200 buses. Within this project, an assessment of the potential of low-carbon buses was made including hybrid, plug-in hybrid electric, and biomethane-hybrid buses. The project also includes last-mile connectivity services with e-pedicabs (electric cycle rickshaw).
Annual GHG reductions of 10,000 tCO2 are achievable using e-buses with the current grid factor of Pakistan. However, total costs of ownership are 20% higher than conventional buses, requiring substantial subsidies. Also, the electric system of Karachi is relatively unstable with many blackouts and with problems to cover peak demands, it added.
The second component of the project, according to the ADB, is to integrate non-motorized transport and pedicabs for last-mile connectivity of the bus system, increasing the attractiveness of the system and allowing for multimodal usage. In total, 300 e-pedicabs shall be integrated with the system, replacing primarily motorized rickshaws.
E-pedicabs combined with zero-emission buses can therefore form an interesting combination for an integrated multimodal zero-emission public transport system.
The ADB study finds that E-buses can be used in BRT systems. However, other solutions including biomethane buses might be financially, technically, and environmentally more attractive as zero-emission buses, especially if the grid is still carbon intensive, fossil fuel prices are low, and electricity supply is relatively unstable. The suitability of technical options toward low-carbon mobility should thus be considered in a comprehensive manner to allow for an optimal and cost-effective solution, added ADB.