Mitsubishi Estate Co., the owner of Shin-Marunouchi Building, and Idemitsu Kosan Co. announced on December 9, 2009, that they have agreed to meet all the energy demands of the building using renewable energy generated by Idemitsu. This will reduce carbon dioxide (CO2) emissions by about 20,000 tons per year. The Shin-Marunouchi Building is a 38-floor skyscraper complex with shops and offices.

It is the first example in Japan of green power, 100 percent renewable energy, being sent directly from power plants to the user. Idemitsu will supply electricity generated at the wind power stations in Aomori Prefecture through electrical grids owned by the electric power company.

Both companies plan to utilize the interregional cooperation structure to promote renewable energy, established by Tokyo, Chiyoda Ward and Aomori Prefecture.