WASEDA ONLINE

RSS

The Japan News by The Yomiuri Shimbun

Home > Opinion > The Great East Japan Earthquake

Opinion

The Great East Japan Earthquake

Heat Wave Caused by Saving Energy: How to Beat the Heat at Home and in the Office

Shinichi Tanabe
Professor, Department of Architecture, Faculty of Science and Engineering, Waseda University

It will be hot this summer. This is not a prediction that this summer will be as hot as last summer, but it does mean that the temperature will be higher in offices and homes to conserve energy. This most certainly is a heat wave caused by power saving activities. The government requested households as well as large and small consumers to conserve electricity by 15%. Because Waseda University is categorized as a large consumer, the university is required by Article 27 of the Electricity Business Act to cut 15% from the maximum electricity consumption of the previous year from nine in the morning to eight in the evening between July 1st and September 22nd, excluding Saturdays, Sundays, and holidays. With a lot of sweat in classrooms, the university as a whole is making efforts to save electricity.

Conserving Power due to the Great East Japan Earthquake Disaster

The Great East Japan Earthquake Disaster occurred on March 11th. Though collapsing buildings had been a major problem in previous earthquakes, remarkably few were damaged by this earthquake because the building meet new quake-resistance standards. On this point, we might also give duly admire the antiseismic measures for buildings and houses. Tsunamis, on the other hand, caused enormous damage. In particular, the accident at Fukushima Daiichi Nuclear Power Plant has cast a dark shadow on the recovery from the disaster, and radioactive pollution is a serious issue as well.

Life and business that had been supported by a stable electricity supply are now significantly influenced. In general, nuclear power plants are required to undergo regular checks every thirteen months. If they failed to obtain approval from the local government for resuming operation, all of the fifty-four plants around the country would cease to work one day. The challenge of conserving energy may not be limited to this summer, but rather it may recur over the next year and subsequent years.

Is the electricity peak truly a peak?

It is said that power has to be conserved to control the peak of electricity consumption. The demand for electricity today, however, does not have a steep point like a peak. The figure below shows the government's estimate of electricity use on the day of the maximum use last summer in the jurisdiction of the Tokyo Electric Power Company. A mountain drags on between nine in the morning and eight in the evening. July 23rd last year recorded approximately 60 million kW, which consisted of 17 million kW for industry, 25 million kW for business including office buildings and schools, and 18 million kW for households. It is not enough to simply restrain ourselves for several hours after a lunch. Though the electricity use becomes moderate for the time being late at night, we must be careful before that. That is why conserving power is difficult.

Cited from the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry, Estimates of the Demand Structure on the Day of the Maximum Electricity Use in Summer (in the Jurisdiction of Tokyo Electric Power Company) [Kaki Saidai Denryoku Shiyo Bi no Juyo Kozo Suikei (Tokyo Denryoku Kannai)], May 13th, 2011.

What can we do to conserve electricity this summer?

The peak electricity consumption of a typical office building comprises about 48% for air conditioning, about 24% for lighting, and about 16% for PCs, copy machines, and other office equipment. For the purpose of saving electricity, you might think of cutting down on air conditioning. Raising the temperature from 26 to 28 degrees Celsius, however, only reduces electricity by 4%. There is something that you should do first: control electricity consumption for lighting and office equipment. This step can decrease air conditioning electricity by disposing of heat generated from office equipment, as well as cut the amount of electricity used by the office equipment itself. Halving workplace lighting can reduce electricity consumption by 13%. Even if the temperature is set higher for the air conditioning, energy use increases rather than decreases if each individual uses a fan consuming 20 or 30W.

On the other hand, houses are subject to larger impacts from external temperature and sunlight. First, it is effective to prevent the midday sun from entering rooms with bamboo blinds or reed screens. The peak electricity consumption consists of about 53% for air conditioning and about 23% for refrigerators. Raising the temperature setting by two degrees Celsius saves electricity by 10%. Of course, it is also effective to restrict electricity for lighting and home appliances.

Do not impair efficiency in the knowledge industry

While you are trying to conserve power, don't you feel somewhat contradictory? We might have no other choices this summer. If this situation continued going forward, however, the intellectual productivity would obviously decline at offices and schools in Tokyo. Daytime work would be less efficient due to sleep being hindered at home. Fewer commuter trains would cause you to spend more time to go to work. You would have to wait longer for elevators. You would have eyestrain in a dark office. Students would not be able to concentrate in class. Would people be able to stand such conditions for long?

The author and his colleagues analyzed annually aggregated data of 13,169 customers treated by about 100 operators at a call center. It was revealed that raising the room temperature from 26 to 28 degrees Celsius decreased the hourly average responses by approximately 4%. You may cut electricity, but this cannot work.

While lower productivity due to conserving power is frequently mentioned regarding semiconductor and other plants, the decline in human intellectual productivity is seldom at issue. The most important industry in Tokyo is the intellectual industry. Economic value is generated through knowledge creation and intellectual activities at offices and companies. Partly due to radiation, many foreigners have left and not returned to this country after the disaster. High-income foreigners working in the financial industry are reportedly relocating their residences to Hong Kong or Singapore. Patience is not enough for us to live under these circumstances long.

What is needed in the medium and long term?

People are actively discussing whether they should choose nuclear power or natural energy. It is, however, inadequate to carry on discussion only from the supply side. We are also required to consider the perspective of the demand side from now on. If zero-energy buildings (ZEB) and houses (ZEH) were realized as a result of super power conservation, we would no longer be twisted around the little finger of the supply-side theories. Smart meters and smart grids could generate a new industry through a combination of energy-saving and energy-creating technologies in Japan learnt from power saving. While European nations lead ZEB/ZEH in terms of policy measures as well as technology, Europe and the United States are not the only leaders. The Korean government decided to introduce them ahead of Japan. Samsung considers constructing ZEH model houses near Seoul in 2010 and exporting Korean products en masse. Super power-saving buildings are also being constructed in Malaysia and Singapore. Japan seems to have been left behind while we have been feeling complacent about believing that Japan is an energy-saving nation.

How should we improve national productivity while controlling energy consumption? Japan needs to have a vision toward that end, I believe.

Shinichi Tanabe
Professor, Department of Architecture, Faculty of Science and Engineering, Waseda University

[Profile]
Professor Tanabe graduated from Department of Architecture, School of Science and Engineering, Waseda University in 1982.
He graduated from the Doctoral Program at the same institution and received a doctoral degree in Engineering in 1987.
After studying at the Laboratory of Heating and Air Conditioning, Technical University of Denmark, and assuming the positions of Assistant Professor, Waseda University, as well as full-time lecturer and Associate Professor, Ochanomizu University, he became an Associate Professor, Waseda University in 1999, and a Professor at the same university in 2001, which is his current position. He has also been a visiting professor at the Technical University of Denmark and Dairen University of Technology.
Major awards Professor Tanabe received include the Award of the Society of Heating, Air-Conditioning and Sanitary Engineering of Japan in 1995; The Prize of the Architectural Institute of Japan (Research Thesis Division) in 2002; and the ASHRAE (American Society of Heating, Refrigerating, and Air-conditioning Engineers) Fellow Award.
Major publications he was involved in as an author or supervisor include Indoor Chemical Pollution [Shitsunai Kagaku Osen] (Kodansha Gendai Shinsho); Introduction to Technology for Near-Future Housing [Kinmirai Jutaku no Gijutsu ga Wakaru Hon] (PHP Research Institute); Kansei Information Processing [Kansei Joho Shori] (Ohmsha); Considering OFFICing Environment [Ofishingu Kankyo Ko] (Libroport); and The Twenty-First Century Style Housing in Japan [21-Seiki-Gata Jutaku no Sugata] (Toyo Kezai).