This is a master thesis performed on behalf of WSP, aiming to investigate scenarios for future energy balances in bidding zone 3 in Sweden during year 2040, based on different production alternatives and consumption scenarios. This report aims to highlight the challenges of transitioning to a more electrified energy system where a greater proportion of renewable sources, mainly from hydro, wind, solar and bioenergy, are integrated into the energy system. Increasing the share of weather-dependent electricity production, such as solar- and wind power, set higher standard on the ability to maintain system balance and guaranteeing sufficient power when consumption is high. Higher consumption will be caused by increased electrification of different sectors, and urbanization, which will be necessary in order to achieve climate goals. Production from other power sources, import of electricity from other bidding zones, and flexibility will have to be considered when the demand for electricity cannot be met by solely the production that takes place in bidding zone 3. In this study, EXCEL is used to build a model that calculates future energy balances and presents the extent that future imports of electricity and flexibility, that will be needed to supply enough electricity to bidding zone 3 in the year 2040. With four different production alternatives and three consumption scenarios, 12 different cases of future energy balances are presented.