Tokyo Electric Power Company Holdings, Incorporated, also known as Toden or TEPCO, is a Japanese electric utility holding company servicing Japan's Kantō region, Yamanashi Prefecture, and the eastern portion of Shizuoka Prefecture. This area includes Tokyo.
Its headquarters are located in Uchisaiwaicho, Chiyoda, Tokyo, and international branch offices exist in Washington, D.C., and London. It is a founding member of strategic consortiums related to energy innovation and research; such as JINED, INCJ and MAI.
Japan's electricity sector, nationalized in 1939 in preparation for total war (the Pacific War), was privatized in 1951 at the behest of the U.S./Allied occupation forces, creating nine privately owned government-granted monopolies, one in a certain region; this included TEPCO. The business model is modeled after the United States electricity industry, which was mostly regulated and privately owned at the time.
In the 1950s, the company's primary goal was to facilitate rapid recovery from the infrastructure devastation of World War II. After the recovery period, the company had to expand its supply capacity to catch up with the country's rapid economic growth by developing fossil fuel power plants and a more efficient transmission network.
During the 1980s and 1990s, the widespread use of air-conditioners and IT/OA appliances resulted a gap between day and night electricity demand. In order to reduce surplus generation capacity and increase capacity utilization, TEPCO developed pumped-storage hydroelectric power plants and promoted thermal storage units.
Today, TEPCO is the largest electric utility in Japan and the 4th largest electric utility in the world after German RWE, French Électricité de France and Germany's E.ON. As TEPCO stands in a leading position in this industry, they have relatively a strong effect for Japanese economics, the environment, and the energy industry.
According to en.wikipedia and Statista