Site:           Chubu Electric Power Company, Inc.
                Electric Power Research & Development Center
                20-1 Kitasekiyama, Ohdaka-cho, Midori Ku
                Nagoya, Aichi-ken, Japan
                http://www.chuden.co.jp/
Date Visited:   7 June 1996
WTEC Attendees: R.D. Blaugher (report author), 
                J. Daley, 
                G. Gamota, 
                P.M. Grant, 
                H. Morishita, 
                R. Schwall, 
                R. Sokolowski
Hosts:          Isamu Kobayashi, General Manager
                Kimio Kamiyama, Deputy General Manager 
                Shigeo Nagaya, Director, Superconductivity R&D
                Hideki Fujita
                Suresh Chand Verma

BACKGROUND

Chubu Electric Power Company, Inc., founded in 1951, is the third-largest electric utility in Japan behind Tokyo Electric Power Co. (TEPCO) and Kansai Electric Power Co. (KEPCO). Chubu delivered 113 billion kWh to its customers in 1995 with an operating revenue of $21 billion. Chubu employs approximately 21,000 people and has 208 in its Research & Development Bureau with a budget of ~$70 million. Chubu's total R&D budget is approximately $150 million. The superconductivity group of seven people (plus seven others) is located within the Electric Power Research & Development Center, which has 117 staff members. The estimated budget for superconductivity, including salaries, is ~$750,000, which is split between SMES and HTS. All of this R&D support is completely internally funded. Additional income is obtained from patents held jointly by Chubu, which retains 50% of the royalties.

SUPERCONDUCTIVITY RESEARCH AND DEVELOPMENT

Largely as a result of having ~20% hydro capacity, Chubu management became interested in the development of SMES as early as 1988. The efficiency for pumped-hydro is low (65-75%); hence, more efficient energy storage technologies such as SMES and flywheels are attractive for providing additional capacity and load leveling capability. Chubu and Hitachi manufactured and tested in 1989 a 1 MJ SMES using Cu/Cu-Ni-stabilized Nb-Ti (7 mm filaments) conductor. The test results showed the expected fast response necessary for system stabilization but with much higher than expected losses in the power conditioning. Chubu management nevertheless was encouraged, and the SMES effort continued internally up to 1991, at which point the internal work was terminated in favor of an external participation in the national ISTEC/SMES program.

The internal SMES effort was redirected in 1994 towards flywheels in collaboration with Mitsubishi and Dowa Mining. The long-range objective for flywheels is development of 1 MWh flywheels to be installed in a large flywheel park comprised of 10 flywheels. Chubu researchers are currently developing a 60 cm flywheel using permanent magnets and 6 cm YBCO bearings with 9 SC/PM assemblies mounted on a ring. The flywheel is to weigh ~180 kg and operate at 10,000 rpm (~0.3 kWh). Higher-speed operation at 20,000 rpm would produce ~1.4 kWh. Chubu researchers are also looking at SC transmission in collaboration with Fujikura on the Bi-tape conductor and with Sumitomo on terminations. Chubu is fabricating short cable lengths for demonstration, with longer lengths under development. The terminations have already been developed and tested with excellent performance. The researchers reported on this activity at the August 1996 IEEE summer meeting. They estimate that 5 x 10⁵ A/cm² is needed for SC transmission.

SUPERCONDUCTOR MATERIALS RESEARCH

Chubu is internally fabricating fairly large (10 cm) YBCO melt-processed "hockey pucks" for the flywheel bearings. Dowa Mining is also involved in the bulk material development. All the Bi-tape conductor work for the transmission effort is carried out in collaboration with Fujikura. Chubu researchers, however, are internally looking at the deposition of YBCO using CVD. The need for low ac losses for superconducting cables is identified as a major concern.

GENERAL OBSERVATIONS

• Chubu management expects R&D on SC-related power applications to continue with high interest for at least another ten years.
• The funding and personnel involved in superconductivity within Chubu should be flat, with no growth or reduction anticipated.
• Storage is the most important activity for Chubu, with flywheels the preferred technology. SMES is thought to be too expensive. Storage is important compared to alternatives, such as gas-fired units, due to environmental issues.
• Chubu management feels SC transmission has enormous potential for long-length transmission with cooling stations located at 10 km intervals.
• Chubu does not anticipate or expect the use of SC devices in the electric power system for at least 20 years.