The Tokyo Electric Power Company, Inc. (TEPCO) has been making
every effort to secure stable electricity supply by output increase
of hydro and thermal power units, purchases of electricity from
other electric power companies and self-generators, and so on.
We anticipate that the balance of demand and supply in
TEPCO's service area*1 tomorrow could be tighter due to the
increase of use of air-conditioners.
Therefore, we have decided to make the Shiobara Power Station ready
for use just in case of severe weather. The Shiobara Power Station
is a pumped storage hydroelectric power station*2(Capacity: 900,000
kW, located at Nasushiobara-shi, Tochigi prefecture), and the
Ministry of Land, Infrastructure and Transport has given a
temporary permission*3 to TEPCO for the use of river water for the
Station. Tonight, we will pump up water from the lower dam(named
Sabigawa Dam) to the upper dam (named Yashio Dam) in order to use
the Station to prepare for emergency situation in supply and demand
TEPCO will continue the efforts to secure electricity supply.
We apologize our customers for any inconveniences and worries
and sincerely ask cooperation for more electricity conservation
*1: TEPCO's service area(Prefecture)
Tochigi, Gunma, Ibaraki, Saitama, Chiba, Tokyo, Kanagawa,
Yamanashi,Shizuoka(eastern part of the Fuji rever)
*2: Pumped storage hydroelectric power station
Because such power stations possess an outstanding characteristic
of taking only a few minutes to reach full output after starting
and requiring only seconds to adjust output, they can quickly
adjust to sudden changes in electricity demand.
This enables them to play a major role in supplying power in the
afternoon when demand is highest.
*3: Temporary permission for the use of river water On Jul. 30,
in accordance with Article 23 of the River Law (permission
for use of river water), TEPCO received a permission for the use
of water for a limited period of July 30 to September 7, 2007
from the Kanto Regional Development Bureau of the Ministry of
Land, Infrastructure and Transport.