Performance simulation of hydrogen-electric transit bus running in a mountain environment

Abstract

As is well known, the transport sector accounts for a third of all final energy consumption in the EU and is responsible for more than a quarter of total greenhouse gas emissions, making it one of the main contributors to climate change. Reducing the negative effects of transport is a strategic objective of the EU, which has put in place a series of actions to promote cleaner and more efficient transport modes, using more sustainable technologies, fuels, and infrastructure. The development of more sustainable and zero-emission collective transport solutions implies the use of novel propulsion systems capable of using energy carriers produced from renewable energy sources. This article deals with the preliminary design and performance analysis of a hydrogen hybrid passenger bus to be used in a mountainous area characterized by mainly curvilinear routes with high gradients both uphill and downhill, within an experimental context of technological-energy innovation. The study is part of a wider project (LIFE3H) co-funded by the European Union, which, among other objectives, intends to lay the bases for the development of a Hydrogen Valley (integrated hydrogen production, storage, and use site), through public hydrogen transport and refuelling stations in the mountain area of “Altopiano delle Rocche” in Abruzzo (Italy). The studied vehicle power-train configuration is based on an electric motor fed by a hybrid power unit consisting of a hydrogen fuel cell functionally coupled with an electrochemical battery. A minibus configuration run over a round trip path according to the real traffic conditions is simulated and main vehicle powertrain components are sized. Finally, hydrogen consumption for traction is estimated.