Chris Mutel, a scientist at PSI's Laboratory for Energy Systems Analysis who specialises in life cycle and sustainability analyses, prepared a challenge for the Energy Data Hackdays happening on the 24th and 25th of September 2021 in Brugg. The title of this challenge is "The When of Green Electric Mobility" and it is about the combining of existing open data and models to help people better understand more precisely potential environmental and economic costs of specific electric cars combined with PV generation at their residence and their mobility patterns.