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23 October, 2015

Japan Secures Minimum Reserve Margin for Winter Electricity Supply, but Heavy Use of Thermal Power Plants Makes Situation “Unpredictable”

On October 20, a subcommittee of the Advisory Committee for Natural Resources and Energy issued a report on the outlook for Japan’s electricity supply and demand for the upcoming winter season.

TEPCO's oil-fired power plants in Tokyo

As was the case in the summer, a minimum capacity reserve margin of 3%—required for the stable supply of electricity—is expected to be secured in the service area of each of the country’s nine power companies. The report will be referred to a cabinet meeting for the formulation of the government’s electricity supply-and-demand measures.

The outlook for the electricity supply was based on the assumption that no nuclear power plants would be restarted during the current fiscal year (April 2015 to March 2016) except for Sendai-1, owned and operated by the Kyushu Electric Power Co., which resumed operation in August. Another assumption was that thermal power plants would still be the major source of supply.

The report notes, however, that more and more thermal power plants have unexpectedly been suspended due to the deterioration of their equipment and components stemming from the high operational rates since the giant earthquake of March 2011. It goes on to warn that the electricity supply situation for the winter season remains “unpredictable.”

According to the report, the number of unexpected suspensions at thermal power plants across the country increased from 483 in FY10 to 590 in FY12, to 604 in FY14.

Beyond the challenge of meeting quantitative demand, a serious issue has been the increase in fuel costs arising from the greater use of thermal power plants (due to the unavailability of nuclear plants). The report presents a trial calculation showing fuel costs in FY15 to be JPY2.3 trillion (USD19.3 billion at USD1=JPY119) higher than if nuclear power were used as a base-load power source in the same way that it had been before the huge earthquake of 2011 (based on the average values from FY08-10).

On the island of Hokkaido, electricity demand reaches its peak in winter. The report particularly warns that Hokkaido Electric Power Co., faces “a risk of more power-source shutdowns than before, and a greater need to be able to respond to them.” At the subcommittee meeting, the Electric Power Development Co. (EPDC, or J-Power) explained its efforts to improve the reliability of the Hokkaido–Honshu High Voltage Direct Current (HVDC) Link.

A trial calculation was also presented at the meeting that revised the capacity reserve margin for Kyushu Electric Power from 4.7% to 8.8% in February 2016, given the October 15 restart of its Sendai-2. In contrast, the capacity reserve margin for Japan’s power companies as a whole rose from 6.2% to 6.6%.

At a regular press conference on October 16, the Federation of Electric Power Companies (FEPC) of Japan addressed this winter’s supply-and-demand situation, saying it “remains difficult on account of the heavy use of thermal power.”

It also said that it would strive to anticipate increased demand due to declining temperatures, while responding to changes in supply capacity resulting from facility-related problems.


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