One of my cousins owns a solar power business in Japan. In this photo, some of his workers install 3000 watts of Sharp "Sunvista" photovoltaic panels on my parents' home in northern Japan.
In Japan two meters are used. The left side meter is consumption. The right side meter is the saved energy. According to my dad, every month the public utility pays 27 yen (or about 20 cents US) for each saved kilowatt hour.