Open-source Simulation of the Long-term Diffusion of Alternative Passenger Cars on the Basis of Investment Decisions of Private Persons

Numerous studies have shown that a full electrification of passenger cars is needed to stay within the 1.5° C temperature rise. This article deals with the question of how the required shares of alternative vehicles can be achieved by the year 2050. In literature the preferred technology are battery electric vehicles as these are more energy efficient than hydrogen vehicles. To be able to demonstrate how alternative vehicles diffuse into the German market, the passenger car investment behavior of private persons was investigated. For this purpose, a discrete choice experiment (DCE) with 1921 participants was carried out empirically. The results of the DCE show that the investment costs in particular are important when choosing a vehicle. This is followed by the driving range, fuel costs and vehicle type. Less important are the charging infrastructure and CO₂ emissions of the vehicle. A CO₂ tax is of least importance. The utility values of the DCE were used to simulate future market shares. For this purpose the open-source software Invest was developed and different scenarios were defined and calculated. This paper shows that conservative assumptions on attribute development leave a large gap until full electrification, as conventional vehicles still account for around 62% of market shares in 2050. In order to achieve full electrification, extreme efforts must be made, targeting the technical and economic characteristics of the vehicles, but also addressing person-related characteristics such as level of information, the subjective norm or the technological risk attitude. A ban on new registrations of combustion engines from 2030 could also lead to a full electrification by 2050. An average annual increase in the market share of alternative vehicles of 2.4 percentage points is needed to achieve full electrification. Other important factors are measures that address the modal shift to other modes of transport (rail, public transport, car-sharing).