Highlights • We present the results of a Delphi study on low-emission heavy-duty trucks in Germany. • A truck’s reliability and an available fueling/charging infrastructure are most relevant. • We identified BE, FCE, CNG and LNG as promising technologies to reduce emissions. • The possibility to enter low-emission zones is a major motivation to use alternative fuels.

Abstract The transport sector is the third-largest producer of greenhouse gas (GHG) emissions in Germany, but within the scope of the government’s climate action plan, the country aims to cut emissions from transport by at least 40% by 2030. Apart from passenger cars, commercial vehicles including heavy-duty trucks (HDTs) are one of the main contributors of emissions. Eco-innovations such as alternative fuel-powered HDTs could change that but diesel is still by far the prevalent fuel of choice. Hence, what factors affect the purchasing decision and operation of low-emission HDTs and which are the most relevant ones? We employed a Delphi study to answer the question of how 34 factors affect the adoption of alternative fuel-powered HDTs in Germany. Our factors combine cost factors, socioeconomic issues, environmental criteria, operational aspects, and political considerations. According to the experts, a truck’s reliability, an available fueling/charging infrastructure, the possibility to enter low-emission zones as well as current and future fuel costs are key factors when purchasing and operating an alternative fuel-powered HDT. In addition, we identified battery electric (BE), fuel cell electric (FCE), compressed natural gas (CNG) and liquefied natural gas (LNG) as promising technologies to reduce emissions from HDTs. Thus, we analyzed motivators, barriers, and ways to overcome the main barriers when switching from diesel to those technologies. Among others, the experts evaluated the possibility to enter low-emission zones as an important motivator, but the fragmented fueling/charging infrastructure as a main barrier. Subsidies are one promising way to spur the penetration of low-emission HDTs.