This is a fund operated by power companies to help spread natural energy. People who want to contribute to environmental protection by reducing CO2 and other emissions give donations (in units of \500 per month) to local power companies when they pay their electricity bill. This money is distributed as subsidies for building solar, wind, and other renewable power generation facilities. The aim of the fund is to promote natural energy power facilities, whose construction costs are high and are thus not yet widespread, and to heighten interest in natural energy among users.