Determining the Distribution of Battery Electric and Fuel Cell Electric Buses in a Metropolitan Public Transport Network

In recent years the world has come under increased pressure to reduce the harmful emissions caused by the burning of fossil fuels. In 2019 in the UK (pre-COVID), the transport sector was estimated to have emitted 27% of all greenhouse gas emissions, making it the highest emitting sector. This has led to government action, banning the sale of petrol and diesel cars by 2030, as well as the introduction of low and zero emission zones in our cities. Public transport modes, especially city buses, must therefore also transition towards zero emission technologies to continue to operate within city centres. Battery electric buses are currently the most common choice, with both single deck and double deck vehicles in regular use. However, long-term operational capabilities are still largely unknown and unreported. Hydrogen fuel cell electric buses are an emerging zero emission technology that have the potential to complement a battery electric bus fleet where the duty cycle is challenging for current battery electric configurations. In this study k-means cluster analysis is used to reduce a typical city bus network to a limited number of representative synthetic drive cycles, against which battery electric and hydrogen fuel cell bus technologies are evaluated. The resulting study derives energy consumption for a given chassis configuration, passenger load and heating requirement to determine the best technology for a cluster of routes. The methodology employed can provide bus operators with a robust mechanism to inform buying decision when transitioning to a zero emission fleet.