Improvement of Efficiency of Power Generation Facilities

Tohoku EPCo is trying to reduce the consumption of fossil fuels at thermal power stations and reduce CO2 emissions through careful maintenance and management of thermal efficiency at thermal power stations, improvement of capacity factors at nuclear and geothermal power stations, introduction of highly efficient equipment in hydroelectric power stations, etc.

Improvement of Thermal Efficiency at Thermal Power Stations

Higashi-Niigata Thermal Power Plant

Tohoku EPCo is making efforts to maintain the thermal efficiency of its thermal power stations at 40% or higher by utilizing to the greatest extent possible its highly efficient power plants such as Higashi-Niigata Thermal Power Station 4-1 System (826,000 kW) as a highly efficient LNG combined-cycle power plant that boasts the world's highest level of efficiency, Higashi-Niigata Thermal Power Station 3 System (1.09 million kW), Units 1 and 2 (1.2 million kW) of Noshiro Thermal Power Station, Units 1 and 2 (2 million kW) of Haramachi Thermal Power Station, etc.

We have taken various measures for Higashi-Niigata Thermal Power Station 4-1 System such as the improvement of turbine temperature management, operation with increased power, etc. As a result, the annual thermal efficiency in FY2004 could be kept at as high as 49.64%.

The level of 50% thermal efficiency can reduce annual LNG consumption by about 200,000 tons and CO2 emissions by about 23% compared with the conventional type of LNG-fired power generation (thermal efficiency is about 39%), making a great contribution to the prevention of global warming.

Thermal Efficiency of Thermal Power Plants

Changes in Capacity Factor for Nuclear Power Plants

Improvement of Capacity Factors at Nuclear Power Stations

As for the capacity factors of nuclear power stations in FY2004, Onagawa Nuclear Power Station (Units 1, 2 and 3) showed as high as 73.3% in total because its capacity factor was improved by the operation with constant rated thermal output, although periodical inspection was conducted at the station over a long period of time. We will continue to exercise due care to ensure safety and maintain high capacity factors.

Operation with Constant Rated Thermal Output

The operation with constant rated thermal output is an operation method that keeps the heat generated by a nuclear reactor constant. This method can generate a lot of electricity in winter when the temperature of seawater (cooling water) is low, and improve the capacity factors of nuclear power stations. Units 1, 2 and 3 of Onagawa Nuclear Power Station started one by one the operation with constant rated thermal output since May 2003.

Improvement of Efficiency of Equipment at Hydroelectric and Geothermal Power Stations

At our hydroelectric power stations, we are striving to increase (improve the efficiency and reduce the loss of equipment) the amount of electricity recovered through the introduction of highly efficient equipment at the time of renewal of water turbines and generators. The annual amount of electricity recovered in FY2004 was 2,538,000 kWh.

Our geothermal power stations are also trying to improve their capacity factors by reducing the number of days of work stoppage, etc.