This article first appeared in Forum, The Edge Malaysia Weekly on February 27, 2023 - March 5, 2023

To achieve economy-wide carbon neutrality in Malaysia, the energy systems that underpin virtually all economic activities need to be deeply decarbonised. While efforts have been made to increase the deployment of renewables, we must look beyond power generation when it comes to achieving such a transformative transition towards net zero. The whole energy system needs to be decarbonised, including the end-use energy demand.

To this end, transitioning away from fossil fuel in the short- to medium-­distance road transport sector presents a low-hanging fruit, given the technological maturity in electrifying them. The newly sealed joint venture between Computer Forms Malaysia and Absolute Energy Thailand to spur public electric bus adoption in Malaysia is undoubtedly encouraging news in accelerating the energy systems transition. Nevertheless, despite having a progressive first step in energy demand decarbonisation, there are some critical points that relevant stakeholders should consider to maximise the decarbonisation impact of public transport electrification.

First, the decarbonisation impact of electric public transport should not be merely measured by the number of electric buses that are deployed, but also by the average number of internal-combustion engine (ICE) vehicles that are taken off the road. Therefore, the success of the electric public transport initiative hinges on its ability to not only retain but attract a higher number of passengers.

At the bare minimum, the location of electric bus charging stations and a relevant charging schedule needs to be strategically optimised. The strategic planning of the charging system should be aimed at preventing an excessive number of new charging infrastructures to be deployed and thus, minimising the grid reinforcement and management costs. This charging system should also be optimised to ensure the battery state-of-charge of public transport fleets is always sufficient and with a safety margin during its operational schedule. This is critical to ensure the operability of a highly electrified public transport system and is also crucial in building public confidence. If electric buses break down frequently due to insufficient charge, it will not only reduce public confidence in the public transport system but also increase consumers’ range anxiety on electric vehicles, which can have a spillover effect of inhibiting the uptake of electric private vehicles. This can cause an unintended negative impact on the energy system transition beyond the public transport space.

In addition, the potential redesign of bus routes in consideration of charging requirements should ensure the proposed new routes can improve the overall transport connectivity and predictability of bus schedules. As the bus routes are being redesigned, relevant ministries should work with urban planners in ensuring the accessibility of the bus stations and improve the infrastructure, such as having more dedicated covered walkways and facilities to promote park-and-ride. These steps to improve the first- and last-mile issue of public transport utilisation are crucial in promoting public transport usage, allowing the low-carbon public transport system to meaningfully reduce society’s reliance on private ICE vehicles.

A significant deployment of electric buses would be translated into a surge in electricity demand. This presents a potential risk if unmitigated — the local residential areas’ peak power demand can increase significantly if most buses are scheduled to charge in the hours when most people are not actively commuting, or public transport utilisation is relatively low but building electricity demand is high. This will result in a greater need for flexible power generation assets to mitigate the higher energy demand in peak hours.

In the case of Malaysia, where new generations of flexible nuclear power plants are unlikely to be deployed in the near term, increasing peak demand will inevitably be translated into the power system’s increasing reliance on carbon-emitting natural gas power plants. Even the best available carbon capture and storage technologies are unlikely to reduce natural gas plants’ emissions by more than 90% while the life span of these new assets will need to be substantially long to justify the high investment cost required. Thus, an electric bus initiative that is not comprehensively thought through can be counter-­productive to the overall net zero transition when the reduction in transport sector emissions is coupled with higher emissions in the power sector while leading us to a potential carbon lock-in risk.

As such, when optimising the routes and charging schedule of electric buses, the relevant stakeholders should ensure the fleets are scheduled to maximise their charging during periods of peak renewable output when the grid emission intensity is low. In some cases, creative ideas, such as having alternate charging schedules for different groups of electric bus fleets, would be worth considering. Policies that encourage electric bus system operators to obtain physical power purchase agreements with dedicated renewable power plants would allow these increases in transport electricity demand to spur the deployment of additional renewable power capacity. This would also allow the system operators to have greater predictability of charging schedules, which could help improve the visibility of power flow and allow necessary actions to be taken to prevent bus charging requirements from overloading the local power network during the existing peak demand hours.

Lastly, there is a need for the system planner to actively think beyond the transport energy demand space and recognise its synergy with the broader power system, especially when we enter into a future with a high share of intermittent renewables. For example, flexibility and adaptability of strategic charging schedules can play a role in providing energy system services like load-shifting.

In a system with a high share of intermittent renewable power generation, huge investments in energy storage assets, such as grid-scale batteries, will be required if the peak demand hours do not align with the peak power generation hours. The batteries of a huge electric bus fleet can serve as energy storage for the system and absorb excess renewable power generation in a time of low demand. Ultimately, strategic planning of bus charging schedules can reduce the investments required in deploying additional energy storage assets and cost-effectively mitigate power system imbalances. In the longer term, there would be merit to study the need case for vehicle-to-grid-enabled electric public transport fleet to provide a wider range of services to enhance the power grid’s resilience, such as back-up electrical power and grid frequency response.

All in all, we are heading in the right direction in energy demand decarbonisation and should think about strategies to maximise the net benefit of such initiatives on the overall net zero transition.

Evan Ng is an energy market consultant focusing on power and low carbon solutions at a leading consulting firm in London

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