Researchers from the Innovation Unit in Transport (CENIT) at the International Centre for Numerical Methods in Engineering (CIMNE) estimate that replacing 772 conventional and hybrid buses in Barcelona with electric vehicles could save €66.5 million over 15 years. The study was commissioned by Transports Metropolitans de Barcelona (TMB), the main public transport operator in the Barcelona metropolitan area.
Overall, the analysis puts the cost of owning and operating a fully electric fleet over 15 years at €794.4 million, compared with €826.9 million for conventional replacement. Allowing for the possible certificate revenue reduces the estimated net cost of electrification to €760.4 million. The findings suggest that higher upfront spending on vehicles and charging facilities could be offset by reduced energy use and maintenance costs.
The estimated savings have two components: €32.5 million from a lower total cost of ownership than renewing the fleet with diesel, gas and hybrid vehicles, and around €34 million in potential revenue from energy-saving certificates (CAE). Under Spain’s CAE scheme, verified energy savings can be converted into certificates and sold to energy suppliers.
Electrifying the fleet would entail an estimated €442.1 million in vehicle investment, compared with €268.2 million for renewing it with conventional vehicles. Infrastructure investment would rise from €5.9 million to €73 million. Over the same 15 years, however, fleet operation and maintenance costs are projected to fall from €547.5 million to €249.3 million.
To produce these estimates, CIMNE researchers analysed data provided by TMB on vehicle and infrastructure costs, energy consumption and prices, mileage and historical maintenance expenditure. They also interviewed technical staff and visited bus depots to check operational assumptions. The assessment covers upgrades to the depots in Horta and Zona Franca, while the Triangle depot is already largely electrified.
Environmental and social impact
The study also projects annual reductions of more than 58,000 tonnes of carbon dioxide (CO₂), 91.7 tonnes of nitrogen oxides (NOₓ) and 594.2 kilograms of particulate emissions from combustion engines. When the associated climate and air-quality impacts are expressed in monetary terms, the report estimates a further €81 million in social benefits.
Conditions for economic viability
Researchers note financial savings depends on several conditions, including maintaining a near one-for-one replacement of conventional buses with electric models, ensuring each vehicle has sufficient range to complete its daily service after overnight charging, and securing manufacturer warranties covering battery replacement. The study therefore presents electrification as economically viable under specified operational and procurement conditions.
About CENIT and its urban mobility research
CENIT is CIMNE’s Innovation Unit in Transport. Its research and innovation activities span transport economics, mobility, logistics and the sustainability of transport systems. Through its Urban Mobility research line, the unit works on public transport optimisation, travel behaviour, electromobility, urban freight distribution and traffic modelling.
