100th year of power transfer between Fukushima and Tokyo

December 3, 2014

Power lines connecting Fukushima and Tokyo mark centennial

http://ajw.asahi.com/article/behind_news/social_affairs/AJ201412030053

By TOSHIHIDE UEDA/ Senior Staff Writer

AIZU-WAKAMATSU, Fukushima Prefecture--With over 300 transmission towers originally erected still in use, the direct transfer of electric power generated in Fukushima Prefecture to Tokyo entered its 100th year of operation on Dec. 3.

The power lines, known as the Inawashiro Kyu-Kansen (old main line of Inawashiro), were built in 1914 by Inawashiro Suiryoku Denki (Inawashiro hydropower), an electric power company that operated during the Meiji (1868-1912) and Taisho (1912-1926) eras.

The utility built the power lines after it established the Inawashiro No. 1 power plant, a hydroelectricity station in Aizu-wakamatsu, Fukushima Prefecture, just north of Lake Inawashiroko. The lines sent electricity generated at the power plant to the Tabata substation in northern Tokyo.

According to Tokyo Electric Power Co., which acquired the Inawashiro Kyu-Kansen after World War II, the entire route connecting the power plant and the substation extended for 225 kilometers and transmitted a total of 115,000 volts, which made it the longest and most powerful system in Japan at the time.

Today, all that remains of the original Inawashiro Kyu-Kansen structures are 335 pylons stretching 89 km that connect the western bank of Lake Inawashiroko with the Nasuno substation in Nasu-Shiobara, Tochigi Prefecture, before the line extends to Tokyo.

Under the guidance of American and British technical advisers, Japanese technicians originally erected 443 transmission towers in this segment of the route. The steel pylons were imported from the United States, and the 335 towers still standing are stamped with markings of Andrew Carnegie's steel company.

Over time, a number of hydroelectric plants, thermal power stations and nuclear reactors were built within Fukushima Prefecture, generating 24 million kilowatts in total.

The residents of Fukushima Prefecture only use about 2 million kilowatts, so the majority of the prefecture's power facilities continue to produce electricity mainly for the Tokyo metropolitan area.

"For the past 100 years, the power lines within the prefecture have not actually belonged to its residents," said an official of the prefectural government.