The THELMA project is a large scale, ambitious project aimed at an integrated assessment of a significant penetration of electric vehicles into the Swiss transport sector, and the impacts on both the Swiss electric grid and Switzerland as a whole. The project starts with a multi-criteria assessment of a broad range of future vehicle designs, using both drivetrain simulation and life cycle analysis. This is extended to the national level using fleet penetration scenarios and transportation demand forecasting to determine the incremental loads on the Swiss grid. Grid simulation then finds costs on the equipment, distribution and transmission levels. Finally, municipal case studies explore the roles of local distributed generation and consumer transport decision making. The goal is to comprehensively assess the tradeoffs and sustainability implications of the increased use of light electric vehicles, as compared to other drivetrains and fuels.