Discussions about alternative energy technologies and fuels have become more prominent in the transport sector. Both public and private sectors are committing to the decarbonization of transport systems.
Public Transport Considerations
Consultant Zutari’s senior transport economist, Marco Steenkamp, addressed the issue of transitioning to alternative fuels for public transport during the Southern African Transport Conference on July 10. He highlighted the developmental challenge of investing in public transport infrastructure in a rapidly evolving environment.
Steenkamp emphasized that transport authorities must plan for future needs while addressing current demands.
Effective decision-making requires policymakers to consider the total cost of ownership (TCO), overall budget impacts, and emission reduction measures, all while being mindful of global trends and domestic priorities.
Economic Viability of Electric Buses
Research cited by Steenkamp indicates that electric buses only reach cost parity with diesel buses after 15 years, or eight years in the best-case scenario with increased renewable energy integration into the grid.
Worldwide, policies aiming for net zero and reduced greenhouse gas emissions are being implemented, especially in Europe and China, under the Paris Agreement.
Countries like China, Japan, and the US offer subsidies and tax incentives for electric vehicle adoption. In South Africa, green initiatives are supported by funding opportunities like the Green Fund and the Development Bank of South Africa’s green bond framework.
Factors Influencing Fleet Conversion
Before converting a bus fleet from diesel to electric, several factors must be considered: depot and electrical infrastructure, charging equipment, bus route lengths, and the bus fleet’s size and composition.
Capital expenditure for both diesel and electric buses includes fleet size, battery replacement, chassis refurbishment, and electrical infrastructure costs.
Operational Expenditures and TCO
Operational expenditures encompass insurance, license fees, fuel or electricity costs, maintenance, and tire replacement. Electric buses would only achieve cost parity with diesel buses after 15 years, primarily due to the high capital costs involved.
Steenkamp noted that the emissions difference between an electric and diesel bus fleet might not be as significant as expected due to the coal-based power generation in South Africa.
A mixed fleet offers marginal TCO savings of about 2% over the buses’ lifespan, while the TCO difference between a full diesel and a full electric fleet is about 14%.
Operational and Capital Costs
While electric buses have lower operational costs and require less maintenance over time, the high capital costs make it challenging to offset these savings quickly. Insurance and license fees might also be higher for electric buses.
The total CO2 emissions for a full diesel fleet scenario constitute about 0.014% of South Africa’s total transport-related emissions. Replacing 12m and 18m diesel buses with electric ones would reduce CO2 emissions by 0.22%.
Over an 18-year period, this would prevent approximately 150,000 tons of carbon emissions. If adopted nationwide, this could lead to a cumulative reduction of about 2.3 million tons of CO2—still a marginal impact.
Conclusion on Electric Buses
Steenkamp concluded that although an electric bus fleet would have lower operational costs over a 19-year period and achieve 14% lower CO2 emissions than a diesel fleet, the total capital cost for electrifying bus fleets would be 118% higher compared to a diesel fleet.
“Emission reduction through a full electric bus fleet remains marginal, with costs breaking even only after 15 years—just four years shy of the buses’ end-of-life,” Steenkamp remarked.