Japan may cap peak-hour power use to avoid blackouts

By Osamu Tsukimori

TOKYO (Reuters) – The Japanese government may cap industrial users’ power consumption during peak hours this summer to avoid blackouts in Tokyo and eastern Japan in the wake of this month’s devastating earthquake, a trade ministry official said on Tuesday.

The magnitude 9.0 quake and subsequent tsunami on March 11 took out 23 percent of Tokyo Electric Power Co’s total generating capacity, leading to rolling power blackouts in most of its service area for the first time in its 60-year history.

While the blackouts have tentatively come to a halt, they are likely to reappear and could be particularly severe in the summer if Tokyo Electric is unable to restore capacity quickly enough to deal with surging demand for air-conditioning.

The government is also considering reinstating daylight savings time and raising prices for peak-hour power, to help balance demand with available supply, but the official, who spoke on condition of anonymity, said blackouts would be held in reserve as a last resort.

“What we need to do is clear: shift peak usage and limit overall power consumption,” he said.

“That would help level out consumption during the day. Our goal is a combination of these strategies that will help to avoid rolling blackouts in the summer.”

Tokyo Electric lost 15,000 MW of capacity after the disaster, and while it has recovered nearly half of that, the more than 9,000 MW at its crippled Fukushima nuclear plants, where it is battling radiation leaks, could be down for an extended period and much of it will likely be lost permanently.


The utility, whose service area accounts for about 40 percent of Japan’s GDP, is bringing mothballed thermal power units back on line to fill the gap but some big thermal plants damaged by the quake are still down.

By summer, it expects to be back at 46,500 MW, still nearly 10,000 MW short of projected peak demand even taking into account users’ efforts so far to conserve power.

The key to filling the gap, the official said, will be limiting peak power use in the hottest afternoon hours between 1 p.m. and 3 p.m.

Restrictions on overall power consumption by industrial users during those hours would be one option, he added.

He noted, however, that industrial power usage tends to hold relatively steady throughout the day while use at commercial buildings and households tends to spike in the peak hours with the increased workload for air-conditioners.

The trade ministry is therefore also considering a pricing system to discourage peak hour use by charging higher rates at those times, although there is some wariness about putting too much of the burden on individuals.

To save power since March 11, commuter lines have been running fewer trains, escalators have been switched off and street lights have been dimmed, as have corridor lights in most government and private office buildings.

These have helped to cut peak demand in Tokyo Electric’s service area by more than 10,000 MW from the year-ago level, as of Monday.

Tokyo Electric has begun publicizing its hourly power supply/demand charts, to encourage conservation at crunch times, and many commercial websites have customized the data in hopes of raising public awareness.

“Efforts to conserve electricity have become more effective over the past week,” the official said. “If they are stepped up further by the summer, it would be possible to get significant results from curbs in power demand.”

(Reporting by Osamu Tsukimori; Editing by Edmund Klamann)

Japan may cap peak-hour power use to avoid blackouts