Buses are the backbone of public transportation systems and play a key role in our cities.
In 2015, buses and coaches traveled 543.5 billion kilometers across European roads. Since most cities face air quality problems, electric buses offer realistic solutions for European cities. This is especially true since the total cost of ownership (TCO) of electric buses will be better than traditional combustion engine vehicle ownership. To be part of this transition to cleaner public transport, Europe needs to catch up: the total electric bus stock in Europe was estimated in 2017 to be around 2,200 while 160,000 electric buses were sold in China that same year.
Electric buses reduce greenhouse gas emissions and lead to a drop in local air pollution, which is a major human health concern (up to 30% of Europeans living in cities exposed
to air pollutant levels exceeding EU air quality standards). According to the European Environment Agency, close to 400,000 premature deaths occur in Europe every year due to air pollution. Given that conventionally-fueled road transport is the largest source of NOx (46% of total EU emissions) and particulate matter emissions, it is crucial to clean-up buses along with other vehicles. In addition to reducing local air pollution, electric buses offer more silent operations in cities than conventional buses, bringing additional health benefits to citizens.
There are three main types of electric buses:
- Full battery electric buses rely on an electric powertrain system powered solely by electrical energy stored in battery packs. These buses are classified in two categories depending on their charging systems: a) overnight charging buses with batteries that are large enough (typically more than 200 kWh) to ensure continuous daily operations and charge slowly during the night at the depot; and b) opportunity charging buses which charge at higher power (up to 600 kW) either at the bus stops or the bus terminals usually through a pantograph (from 30 seconds to about 10 minutes depending on the charging power and the size of the battery).
- Fuel cell electric buses are buses that include fuel cells and a battery. Fuel cells provide direct electric traction or generate the energy needed to keep the batteries charged.
- Trolley buses are electric buses powered by two overhead wires. Battery packs can be fitted to these buses, thus reducing the need to build the required infrastructure in cities.