This study investigates how electrification of the Scandinavian and German road transportation sectors under a stringent CO2 cap will influence investments in new electricity generation capacity up to Year 2050 and the dispatch of the electricity generation portfolio in Year 2030. We apply a cost-minimisation investment model and an electricity dispatch model of the Scandinavian and German electricity systems, assuming both optimised charging and a vehicle-to-grid (V2G) charging strategy for passenger electric vehicles (EVs). Different EV battery sizes and EV deployment levels are investigated in 11 different scenarios, whereby two of the scenarios include also electric trucks and buses using electric road systems (ERS). The results of the modelling show that with a cap on CO2 emissions, the additional electricity demand from an electrified road transport sector is met mainly by increases in the outputs from wind power and thermal power plants, in the form of coal in combination with carbon capture and storage. In Year 2030, wind power generation in Scandinavia and Germany increases by 7-30% depending on the EV scenario, as compared to a scenario without EVs, which corresponds to a few more percentage points than the increased demand from EVs in absolute terms. Furthermore, a V2G charging strategy for passenger EVs smoothens the net load curve and almost completely reduces the need for peak power capacity in the Scandinavian-German electricity system. The value of investing in solar power is also reduced in all the EV scenarios by 22-42%, as compared to a scenario without EVs. This is due to the fact that in Northern Europe solar power competes with EVs for peak power supply. ERS for mainly trucks and buses will increase the current load profile by up to 18 GW in the Scandinavian-German electricity system.