The paper describes analyses of profitable increases in cross border capacities in Europe to 2050 in 4 scenarios with different RES-E shares. The analyses use the power market simulation model EMPS and an investment algorithm sequentially for each decade. Considerable increases in transmission capacities will be necessary. Capacities are more than doubled in 2050 compared with 2010 when profitable investments are carried out. The additional capacity varies from 120 GW to 713 GW dependent on the volume and location of the new renewables. The increase is highest in a scenario that is dominated by large scale offshore wind production and import of solar based production from Africa. Another scenario mainly based on local and regional production has the lowest emissions, the lowest power prices and much lower need for new transmission capacity.