Tokyo -- Japan plans to double its regional electrical grid capacity by adding up to 23 million kilowatts, according to a plan compiled by the industry ministry and an organization representing energy operators. New routes are planned to connect the largest northern island of Hokkaido and the southern island of Kyushu via the main island of Honshu. The move is aimed at helping Japan reduce greenhouse gas emissions to net-zero by 2050, for which renewable energy sources -- including offshore wind -- are critical. A major challenge has been weak grid connections traversing regions.