WASEDA ONLINE

RSS

The Japan News by The Yomiuri Shimbun

Home > Opinion > The Great East Japan Earthquake

Opinion

The Great East Japan Earthquake

Smart Grid Creates the Future

Yasuhiro Hayashi
Professor, Faculty of Science and Engineering, Waseda University

The accident at Fukushima Daiichi Nuclear Power Plant caused by the East Japan Great Earthquake Disaster has made it necessary to fundamentally revise the existing nuclear-centric energy policy. In addition, though it has been said that Japanese electricity system is highly reliable, unprecedented and extensive planned power outages were implemented within the jurisdiction of the Tokyo Electric Power Company (TEPCO) in March, partly due to the loss of a considerable portion of capability for electricity supply. Facing such an unparalleled situation, how should Japan develop energy policy and electricity systems?

Relationship among CO2 emissions, economic activity, and energy consumption

Kaya's equation is an equation simply explaining the relationship among CO2 emissions, economic activity and energy consumption as follows:

(CO2 emissions) = ((1) Gross domestic product (GDP)) × ((2) Energy consumption per GDP) × ((3) CO2 emissions per energy consumption)

This equation provides a guide about what a society should do to reduce CO2 emissions, or fossil fuel consumption. In this equation, reducing CO2 emissions or fossil fuel consumption requires the decrease of the three factors (1) to (3). Because cutting (1) depresses economic activities, it is essential to diminish (2) and (3) in a well-balanced fashion.

Reducing (2) means promoting energy saving. While saving electricity or cutting electricity use would be an important countermeasure against electricity shortage for the time being, it is also necessary in the medium and long terms to efficiently decrease energy consumption in general-including electricity, gas, and petroleum-in every aspect of life and production.

Suppressing (3) indicates using electricity generated by methods that do not emit CO2, such as nuclear power and renewable energy, or thermal power generation that is highly efficient and emits fewer CO2. This also includes use of biogasoline, biogas, and natural gas for transportation as well as thermal application.

Given that this accident has greatly shaken the safety and reliability of nuclear power, it will be unavoidable to reduce our dependence on it. To cut CO2 or fossil fuel consumption even in such a situation, it would be important to take measures such as promoting energy saving, popularizing and expanding the use of renewable energy, increasing the efficiency and reducing carbon emissions of thermal power generation, promoting a shift to natural gas, more than ever. The smart grid-a combination of electricity systems and communication networks-is an infrastructure for supporting these.

Promotion of energy saving

The next-generation meter is called smart meter, which is equipped with functions for reading a meter at a regular interval such as thirty minutes, interactive communication, remote opening and closing, and the like. If it prevailed, consumers would be able to know about their own consumption of electricity, gas, water and other types of energy. This is expected to drive a shift to a lifestyle that enables us to save energy in general, as well as promote replacement with devices that consume less energy. If the energy management system (EMS) was widely used as well, improvement in the quality of life and energy saving might be achieved at the same time, through optimal control of solar light, heat pump water heaters (HP), electric vehicles (EV), storage batteries, and other such devices.

The popularization of these two systems would enable us to communicate schedules of planned power outages in advance, implement planned power outages with a switch on the meter, make minimal electricity available even during planned power outages, and carry out optimal control of devices by EMS with such minimal electricity. This way, these systems could improve planned power outages about which consumers have felt burdensome or frustrated.

Popularization and expansion of use of renewable energy

Because solar light and wind power have large output fluctuations, their dissemination would make the electric systems unstable, hindering further implementation. The smart grid requires stabilizing efficiently at a low cost to further popularize those types of energy.

Though both solar light and wind power have large output fluctuations, treating them as a large group generates a so-called the smoothing effect. So, an economically reasonable way is to seek stabilization in the electricity system as a whole. It is, therefore, important to implement combinations of cost-efficient measures chosen from various types ranging from power generation to electricity demand, such as control of renewable energy, improved power plant operation, advanced electricity networks, utilization of demand responses (DR) through which consumers change their electricity use responding to electricity prices that fluctuate every several hours according to the state of the electricity system, and installation and utilization of storage batteries, while first making the most of the ability to adjust existing thermal power, water power including water pumping, and electricity networks.

Because the receptivity for and effectiveness of DR can be enhanced by the popularization of HP, EV, energy storage devices including storage batteries, and EMS, it is effective to utilize DR while making efforts to popularize these devices, which also contribute to energy saving.

In addition, if an enormous amount of storage batteries widely used by consumers for various purposes could be partly borrowed when they are not used, it might contribute to both the popularization of renewed energy and diffusion of storage batteries on the consumer side. So, it is required to develop technology for utilizing storage batteries in the electricity systems while enhancing the performance of storage batteries.

Development and demonstration of these smart grid technologies are currently conducted through collaboration among industries, government, and academia. Their fruits are expected to help solve global warming and energy issues, as well as to enhance the position of Japan and drive the growth of Japanese companies.

Yasuhiro Hayashi
Professor, Faculty of Science and Engineering, Waseda University

[Profile]
1989: Graduated from Department of Electric Engineering, School of Science and Engineering, Waseda University
1991: Graduated from the Master's Program, Graduate School of Science and Engineering, Waseda University
1994: Graduated from the Doctoral Program, Graduate School of Science and Engineering, Waseda University, and received a doctoral degree in engineering
April 1994: Became a Research Associate, Department of System Engineering, College of Engineering, Ibaraki University
April 1997: Became a Lecturer, Department of System Engineering, College of Engineering, Ibaraki University
April 2000: Became an Associate Professor, Department of Electrical and Electronics Engineering, Faculty of Engineering, University of Fukui
April 2009: Became a Professor, School of Advanced Science and Engineering, Waseda University
December 2009: Concurrently became the president, Research Institute for Advanced Network Technology (RIANT)

[Publications]
Calculation of Optimal Power Flow in the Electrical Grid [Denryoku Keito no Saiteki Choryu Keisan] (The Japan Electric Association)Link(Co-authored)
Configuration Technology and Standardization of Smart Grid [Sumato Guriddo no Kosei Gijutsu to Hyojunka] (Japanese Standards Association) Link(Co-authored)
Studies on Smart Grid [Sumato Guriddo Gaku] (Newspaper Division, The Japan Electric Association) Link(As an editor and author)

[Academic Activities, etc.]
IEEJ (The Institute of Electrical Engineers of Japan), IEEE (The Institute of Electrical and Electronics Engineers, Inc.), The Institute of Electrical Installation Engineers of Japan, etc.
Technical Editor, the Treatise Committee of Power and Energy Society, and Organizer, the Editorial Committee, etc., IEEJ
A member of the Study Group on Mid- and Long-Term Operation, Electric Power System Council of Japan
A member of the General Electrical Network Technology Investigation Committee, The Institute of Applied Energy
A member of the Study Group on Cost-Benefit Analysis, Agency for Natural Resources and Energy, METI (Ministry of Economy, Trade, and Industry)
A member of the Investigation Committee on Utilization of Overseas Interconnected Lines, Agency for Natural Resources and Energy, METI
The Study Group on Technology Related to Distributed Generation and System Stability, Agency for Natural Resources and Energy, METI
A member of the Editorial Committee, KIEE (The Korean Institute of Electrical Engineers)
The Best Teacher Award of Department of Electrical and Electronics Engineering, Faculty of Engineering, University of Fukui awarded in 2002 and 2006
The Electricity Academic Promotion Award (for excellent papers) awarded from IEEJ in 2008
Chair, the Study Group on the Smart Meter Scheme, METI (2010)
A member of the Study Group on the Scheme for Next-Generation Power Transmission and Distribution Systems, METI (2010)
A member of WG 1, the Study Group on the Scheme for Next-Generation Power Transmission and Distribution Systems, METI
A member of WG 2, the Study Group on the Scheme for Next-Generation Power Transmission and Distribution Systems, METI
A member of the Subcommittee on Schemes and Environment, the Sectional Committee on Electricity Industry, the Advisory Committee for Natural Resources and Energy, METI