Sankyozawa Power Station

Where Japan's First Hydroelectric Light Shone

The Sankyozawa Power Station (三居沢発電所) is the single-storey wooden powerhouse of a hydroelectric station, built in 1909 in Aramaki, Aoba Ward, Sendai City, Miyagi Prefecture, and registered as a Registered Tangible Cultural Property (structure) on August 23, 1999. The Agency for Cultural Affairs describes it as the second building of the first power station in the Tohoku region.

The Agency records it as a single-storey timber building with a steel-sheet roof and a building area of 169 square metres; registration number 04-0025, owned by Tohoku Electric Power. Its ridge tag names the master carpenter Ito Kesagoro and his deputy Ito Risaburo (Agency for Cultural Affairs).

Japan's First Hydroelectric Power

According to the Japan Society of Mechanical Engineers, it was here in 1888 that the Miyagi Spinning Company lit electric lamps with the first hydroelectric power in Japan. After changes to the turbine and generator capacity, the station has run continuously since 1910 and is still in service; Tohoku Electric Power took it over in 1951.

The society designated the station's machinery and records Mechanical Engineering Heritage No. 26 in 2008, and notes that surplus power from the station was used in 1902 for Japan's first successful production of calcium carbide in an electric furnace.

Why It Was Registered

The Sankyozawa Power Station was registered as a building that contributes to the historic landscape of the country. The Agency for Cultural Affairs notes its almost square plan, clapboard walls and distinctive exterior.

What to Look For

The Sankyozawa Power Station has a hipped (Yosemune-zukuri) roof whose centre is raised to carry a small gabled roof, its long sides glazed as clerestory windows (Agency for Cultural Affairs): a roof-top lantern that lets light into the generator room.

According to the Japan Society of Mechanical Engineers, the station produces up to 1,000 kilowatts, normally 290 kilowatts. The generator is a Siemens three-phase 3,300-volt unit installed in 1924 and still in use in partly original form, and brick remains of the original water channel survive beside the modern penstock.

Visiting the Sankyozawa Power Station

From Tohoku Electric Power's Sankyozawa Electricity Centennial Museum next door, you can look into the working Sankyozawa Power Station (Japan Society of Mechanical Engineers). The museum is open 10:00 a.m. to 4:00 p.m., admission free; check its website for closing days. The address is 16 Sankyozawa, Aramaki, Aoba Ward, Sendai; telephone 022-261-5935.