Energy and Environmental Benefits of In-Motion Charging Trolleybuses: A Case Study of Vilnius

Abstract

Reducing greenhouse gas (GHG) emissions depends mostly on urban transport electrification. However, the role of trolleybus systems in this process is still under discussion. The objective of this study was to analyze the viability of trolleybus buses in relation to diesel buses regarding environmental and economic aspects. The research was conducted in Vilnius, Lithuania using an extended CO2 emission methodology incorporating physicochemical fuel properties and real-world operational data that allowed us to estimate CO2 emissions and economic impacts. The findings indicate that the Vilnius trolleybus system prevents 84,996.32 kg of CO2 emissions monthly compared to diesel buses (gross avoided emissions). After accounting for emissions from electricity generation (based on Lithuania’s 2023 grid mix), the net avoided emissions are approximately 61,569 kg of CO2 per month, equivalent to EUR 4284 in carbon credits. The system also significantly reduces local air pollutants. Moreover, the new In-Motion Charging (IMC) technology improves system flexibility by decreasing dependence on overhead wires and maintaining low emission levels. IMC trolleybuses represent a cost-efficient option compared to battery-electric buses (BEBs) and hydrogen fuel cell buses (FCEBs). Our findings support the European Union’s decarbonization goals and provide essential insights for policymakers considering public transportation electrification efforts.