BERLIN (AP) - Japan's Mitsubishi is investing €576 million ($770 million) in developing German offshore wind farms. Netherlands-based grid operator Tennet said Wednesday that Mitsubishi will take a 49 percent stake in the €2.9 billion high-voltage cables linking four offshore farms to the German grid. The four plants have a total production capacity of 2.8 gigawatts, more than two average nuclear reactors. Linking the wind farms, some of which are more than 100 kilometers (60 miles) offshore, to electrical grids is costly. Tennet needs to invest a total of €5.8 billion to connect ten offshore wind farms, and has been struggling to finance the grid expansion. Germany is phasing out nuclear power by 2022 in favor of renewable energies instead, and offshore wind is expected to become one of the main energy sources.