Saving Electricity in a Hurry—Tokyo Has Done It Before and Can Do It Again

March 9th 2011
A TEPCO spokesperson providing an update during Tokyo's 2003 power shortfall

Not long ago, Japan faced a major power crisis. In September 2002, the Tokyo Electric Power Company (TEPCO) was forced to shut down 17 nuclear power plants for emergency safety inspections.

The winter of 2002-2003 was approaching, and the plants, which were expected to remain closed for months, would be unavailable through summer 2003, a time when demand from summertime air conditioning would normally require those plants to be operational to meet demand.

How Tokyo successfully found ways to conserve electricity and avoid blackouts for months even without 17 nuclear plants is related in the book Saving Electricity in a Hurry, published by the International Energy Agency (IEA).

The book was researched and written by Alan Meier, a scientist in the Environmental Energy Technologies Division of Lawrence Berkeley National Laboratory, while he was on leave as a senior advisor at the IEA. One of the other ten "vignettes" examines how California coped with its electricity crisis of 2000-2001.

Among the many challenges faced by Japan today in the aftermath of its earthquake-tsunami-nuclear plant crisis is the problem of meeting electricity demand after the loss of power from its stricken plants. "Today's supply-demand situation in Japan is almost a repeat of 2003 but without the luxury of advance warning," says Meier. At that time, TEPCO was concerned about the summer, because it anticipated a peak demand of 64.5 GW (Gigawatts, or trillion watts of electricity), and without the 17 nuclear plants, it would be 15 percent short of capacity.

In late 2002, TEPCO began negotiating for additional supplies from neighboring utilities. However, the ability to trade electric power is limited because, as the book notes, "there is relatively little transmission capacity between Japanese utilities." TEPCO and utilities to its east operate at 50 Hertz (Hz), and western Japanese utilities, at 60 Hz, making it impossible to transfer power between these regions.

Advancing the opening of new thermal power plants under construction would not get the needed spare capacity by summertime, so in January 2003, TEPCO began a encouraging its customers to conserve energy, and the Japanese government launched its own media campaign. By April 2003, all 17 plants were shut down.

"With the looming threat of power cuts," says the book, "manufacturers began reviewing their production schedules. Toshiba, Hitachi and Kobe Steel created plans to increase production at night or on weekends when electricity demand is lower."

Some factories planned to use less electricity in areas where it would not affect production; others switched off air conditioners or moved their setpoints higher. TEPCO teams visited large customers to help them develop conservation plans, while the government formed energy-saving teams (led by a popular Japanese actress) to visit local companies and shops, asking them to help out by conserving.

As the air conditioning season began in June, TEPCO offered electricity demand information on television every day. They also started a website that displayed power demand and available capacity in real-time. This was modeled on a website created by Meier and an Berkeley Lab team during California's own electricity crisis of 2000-2001. (California's electricity demand and capacity are now tracked and displayed in real-time by the California Independent System Operator.)

TEPCO's program to save electricity in a hurry was a success. TEPCO estimated it saved 1.4 GW by adjusting its contracts with large industrial and other customers, and another 1.3 GW. But, perhaps more important, Tokyo got a break from the weather, when the summer proved to be cooler than normal, and peak demand never exceeded 57 GW.

The combined 2.7 GW savings was about 4.5 percent of TEPCO's peak demand at 60 GW. Some mothballed thermal power plants returned to service later in the summer, and the utility declared the crisis ended in September.

A survey conducted by the Center for Consumer Studies of Dentsu, Inc. found that 80 percent of respondents claimed to have taken measures to reduce their electricity use—77 percent by dimming lights, 60 percent by raising the setpoint of air conditioners, and 50 percent by reducing air conditioning use.

"These savings were probably enough to have prevented blackouts," said Meier, " But it's difficult to be sure because of the cooler than normal summer."

In 2008, Meier was able to apply the lessons of his IEA study to help the city of Juneau, Alaska, with its own power crisis. There, an avalanche severed the electrical transmission line that supplied 85 percent of the city's electricity needs. Meier flew to Juneau and advised city leaders on how they could save electricity in a hurry. Juneau managed to reduce its electricity use by 30 percent.

Meier believes that Tokyo can save electricity in a hurry again. "The first step is establishing a positive, constructive, electricity-saving campaign that makes the consumers feel like they are part of the solution," he says.

Meier added, "A tragedy caused the problem but now we need to avoid compounding it."

Allan Chen