Nine European countries want to coordinate the generation of environmentally sound electricity using a huge high-voltage grid in the North Sea. Offshore wind parks, solar power facilities onshore, and hydroelectric power plants are to be networked as part of the endeavour.Many believe it’s a milestone in the development of green energy. They argue that the existing weaknesses – a lack of supply security and differences in production due to weather – could be balanced out across Europe. But the North Sea alliance is still just beginning, with wrangling over the costs and who will run the project.