Powerful savings

By K.N.C. | TOKYO

JAPAN has been dreading a major energy shortage in the north-east, after a quarter of the region's power-generation capacity was damaged by the quake, tsunami and crisis at the Fukushima nuclear power plant. But a summer of rolling blackouts may be avoided.

TEPCO, the Tokyo regional power company, has been able to bring online more power plants than it anticipated initially. Instead of an 8-gigawatt (8GW) shortfall, it now expects to suffer a shortage of only 3GW, as a story in this week's paper explains. Demand is estimated to peak at 55GW, which leaves room for basic energy-saving measures, like using less air-conditioning and lighting, to avert a power crunch with capacity to spare.

The accompanying chart, describing usage in TEPCO's service region, explains why. It is a forecast of energy use this summer in the greater Tokyo area over a 24-hour period, by Japan's Institute for Sustainable Energy Policies. It shows the enormous variability between “base load” and “peak load” among different energy users.

Industry, at the bottom, takes a steady draw of energy: about a quarter of all power used during peak hours. The increase from trough to peak is minor: only around 25%.

Next come households, who have fairly constant energy use until the evening spike that occurs between 5-10pm. Their usage is as much as three times higher at its peak than at its nadir. Here there is low-hanging fruit. Lowering the air-conditioners (that is, raising temperatures) would lower peak-load consumption tremendously. But there is opportunity for “time-shifting” too, such as running the washing machine before 10am or after 8pm—which otherwise is when power demand is greatest.

But the most promising site for new conservation is commercial users (such as office buildings and retailers). Their use is around ten times higher at its peak than at its trough. Lights and air-conditioners account for much if it. Many retailers, including Earth-loving brands like Body Shop, Birkenstock and The Gap, keep their doors wide open during the hot Japanese summer, letting cool air stream onto the sidewalk. The better to lure in sweltering window-shoppers? Regardless, ending this inane practice could save a lot of precious electricity.

Japan is rightly celebrated for having the most energy-efficient economy in the world. The energy consumption per unit of output in America and Europe is around twice that of Japan's, and China's is eight times as much. But the efficiency of Japanese industry hasn't been matched in other sectors of the economy. Although industry uses roughly the same amount of energy today as it did before the oil shocks in 1973—even while the economy grew to become two and half times larger—household usage has grown at a faster pace than the economy as a whole.

The residential and services sectors are where the waste is, and that is where the conservation ought be. Cutting back the power supply available to Japanese industry would be unnecessary and unwise. There are better places for conservationists to spend their energy.