EU's RES-E targets for 2020 and the corresponding national action plans will connect large amounts of non-controllable renewable power generation to the grid, if plans are implemented. This gives increased need for production technologies that easily can balance demand with supply at moderate costs. In this project we have considered alternative power transmission grids in the North Sea, which will connect controllable Norwegian hydropower stronger to the rest of Europe. The power market in northern Europe is simulated for year 2020 using the EMPS model. Renewable power generation is set in accordance with national action plans, while the rest of the system is updated in accordance with forecasts for 2020. We consider different connection points for a direct connection between Norway and GB, cases where the cable is connected to off-shore nodes that include wind-farms and electrification of petroleum installations, and more integrated cases that include a connection to Germany. Each case is evaluated in a cost-benefit analysis. Additional cases show effects of changing assumptions, notably for the amount of wind-power installed in the North Sea, phase-out of German nuclear power and trade the boundary of the simulated system. In the final evaluation, we discuss major finding as well as uncertainties and limitations of our study.