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No.1 (March, 2012) Special Issue on Smart Energy Solutions

Vol.7 No.1 (March, 2012)

Special Issue on Smart Energy Solutions

ABE Rikiya, Ph.D.

The large scale deployment of wind-generated power, solar power and other power from renewable energy sources cannot be achieved without overcoming fundamental issues with the existing electric power grid and the urgent development of new power supply systems. This special article will introduce the reader to the Digital Grid concept - the convergence of power and information in a next-generation network architecture that holds the potential to revolutionize power transmission networks. In this architecture, IP addressed digital grid routers mutually interconnect a “cell grid” of distributed asynchronous power networks, while digital grid controllers enable inter-cell power transfers. Through the adoption of this architecture, the large-scale deployment of a renewable energy-based power system can be a reality.

EV charging infrastructures

CHIHARA Shinpei ・ISHII Ken’ichi

Although the electric vehicles (EVs) are expected to be marketed as clean vehicles without emissions, the preparation of charging infrastructures will be an essential requirement for their popular acceptance. NEC is developing an EV charging infrastructure system that is equipped with remote operation/maintenance and energy control functions as well as an authentication/billing function. This will allow the business operators to install and operate charging stations efficiently and safely. In addition, NEC is also advancing activities for standardizing the system interfaces between various vendors for making the charging stations usable by anyone regardless of the system vendors or business operators. This paper introduces our activities for supporting the preparation of EV charging infrastructures.

ISHII Yuko ・SHIZUNO Takayuki ・KOGURE Junji ・ITABASHI Noriyuki ・
WATANABE Hideto ・NYU Takayuki

NEC has developed a Battery & Charger Integration System (BCIS) to support the burgeoning infrastructure for electric vehicles (EVs). The system controls several quick chargers and large capacity stationary batteries and thereby enables charging time reductions and peak charging power reductions while simultaneously charging multiple EVs. By conducting field trials as part of the Yokohama Smart City Project (YSCP) while linking with the Community Energy Management System (CEMS), we are aiming to examine how much BCIS can contribute to the demand and supply adjustment for community. This paper introduces an outline of the BCIS and of its field trials.

SUGAWA Masashi

EV development test systems are used to test the performance of motors and inverters for hybrid and electric vehicles by simulating the behaviors of the component parts of an electric power train. They are compatible with HILS systems, which simulate an entire vehicle by combining an EV power emulator and a vehicle control simulator. This paper outlines the recent technological advances in EV development test systems and introduces a battery charge-discharge test system.

TOKIWA Masahiko

Preparation of battery charging infrastructures is the key to the dissemination of electric vehicles. Some types of EV chargers are already available according to applications. We would like to introduce the need for the CHAdeMO protocol that allows any vehicle to be charged optimally and the functional specifications and technologies applied to the large-capacity EV Fast Charger “TQVC500M3” that features battery recharging at the most rapid rate.


EVs and PHVs are about to start spreading due to growing environmental awareness. However, since significant electric power is required to charge these vehicles, it is not easy to install new charging facilities in the car park of an existing apartment building.Accordingly, we have developed a charge controller as a key device for realizing the provision of safe, secure and convenient charging services so that a user can reliably use charging services outside the house, even for EVs and PHVs, just like refueling a gasoline vehicle. A single charge controller can control multiple chargers and enables not only support of charge operations but efficient management of authentication/billing and charger operation through collaboration with EV charging cloud services.

Energy storage system

NOGUCHI Masayuki ・IIDA Akira ・OOMACHI Satoshi ・HAMADA Kiyotaka ・KANOUCHI Osamu

NEC is marketing a lithium-ion battery-based household energy storage system capable of the automatic control of power consumption in households. Based on extensive use of NEC’s energy storage, control and cabinet technologies, it is an energy storage system for houses that is capable of efficient interconnection with grid and solar-generated power sources. This paper gives an outline of this energy storage system and describes the individual technologies that are used.

SAITOU Kazumasa ・TSUJI Kenichiro ・MUKOUYAMA Kouji ・KANAMARU Yuji ・WAKAO Ippei

NEC has been developing an energy storage system for industrial and grid use. We have been applying our expertise in this regard in developing the energy management system of the “Yokohama Smart City Project (YSCP)” selected as “Next-Generation Energy and Social Systems Demonstration Areas” implemented by the Ministry of Economy, Trade and Industry in Japan. We have also conducted the overseas field trials of a large-scale energy storage system using a lithium-ion battery technology in collaboration with the U.S. Electric Power Research Institute (EPRI). Furthermore, we have started to examine the introduction of an energy storage system for the Italian electricity company Enel and a self-sustained power supply system for the Indonesian islands.

SAITO Hideaki ・KOJIMA Ikuo ・OHTA Tomoyuki

We at NEC Energy Devices, Ltd. develop and manufacture large-capacity lithium-ion batteries (LIBs) for use in electric vehicles (EVs) and large energy-storage devices. The LIBs of the NEC brand feature a manganese positive electrode with a laminated structure in order to achieve high safety and long life. We have established a mass-production method, achieving an annual electrode production capability of over two million kWh. At NEC Energy Devices, Ltd., we utilize our unique technology and mass-production capability to provide low-priced electrodes and batteries not only for EVs but also for drive power supplies and power supplies for energy storage as well.

KAWASAKI Daisuke ・ISHIKAWA Hitoshi ・SUDO Shinya ・UTSUGI Koji

NEC Green Innovation Research Laboratories have developed a lifetime extension technology for laminated lithium-ion batteries (LIBs) using manganese positive electrodes featuring safety and high abundance as a resource. This technology uses a NEC-original electrolyte additive and maintains a capacity of 85% even after about 20,000 cycles (1,435 days). Based on the test results, including the above data, a lifetime prediction simulation was performed with an LIB drive pattern assuming the battery-charge from a commercial power supply at nighttime. It was concluded that in the Tokyo area the period until the capacity is halved from the initial capacity is 32 years. This paper introduces the activities summarized above.

NANBA Mitsunari

The key to realize a low-carbon society is the efficient use of a variety of energy systems.We would like to introduce the functional specifications and technical details of a multi-source power conditioner that combines optimally storage batteries and solar power generation etc.

Energy Management System (EMS)

KIKUCHI Kyosuke ・SUETSUGU Takeshi ・SATOU Tsuyoshi ・HAMADA Uichi

Interest in HEMS (Home Energy Management System) is growing as a technological solution to achieving energy supply stabilization and greenhouse gas reduction. NEC has been involved in the experimentation and verification of HEMS, such as measuring the impact of “visualization.” Based on these results, NEC developed the HEMS Solution and began marketing it from July 2011. This paper introduces our efforts until now, the characteristics of the solution, and its future possibilities.

OZAKI Takayo ・TAMURA Tetsuya

Under the increasing severity in the availability of power supplies and the associated legal restrictions, the visualization of energy is evolving from simple viewing to visualization for the improvement of business. This paper introduces methods of visualization and analysis for the latter purpose together with actual case studies.


Ever since the Great Tohoku Earthquake, energy saving on the part of businesses has become an urgent task in Japan. And increasingly more attention is being focused on the office, where energy-saving measures have taken longer to adopt. This paper introduces the SaaS type service “EnePal Office” which supports energy-saving at offices that are lagging behind, by not only applying “Visualization” to office energy consumption but also by providing a Navigation System to help save energy.

HARA Akihiro ・KITAMURA Mitsuhiro

The Great East Japan Earthquake of March 11, 2011 has changed our attitude regarding energy supply in Japan. In the past, we needed only to follow the guidelines of the annual energy usage amount indicated in the “Revised Act on the Energy Saving.” However, we are now and in the future requested to personally comprehend the per-hour energy usage amount per building and even for each area or section of a building. The summer of 2011 was the so-called “summer of patience,” and enterprises were asked to reduce their investment in facilities, etc. However, for the winter of 2011 towards the summer of 2012 and into the future we have been requested to introduce systems to monitor energy wastage and to control energy usage for optimum saving. NEC offers solutions for the “visualization” and “optimum controls for saving energy” as well as “Smart Buildings” (BEMS) to provide optimum energy supply and demand by developing grid interconnection control systems. These solutions are intended to support energy storage and to enable the creation of stable energy supply.


Our world is undergoing radical changes with the rapid spread of photovoltaic (PV) power generation and Japan’s review of energy policy since the earthquake. We can say that it is becoming increasingly important to finely control a proper balance of the power grid as we shift from an age of merely “purchasing” electricity through a power company to an age of “producing” and “saving” electricity on the demand side. NEC is effectively using the basic technology cultivated for many years in the construction of monitoring control systems for social infrastructure equipment. Quick monitoring control technology is being developed over a wide area and is being demonstrated for energy equipment installed in various social infrastructure equipment or users’ premises. This paper introduces its development and future product development.


Since 2006, NEC has been a participant in a project reviewing the possible automation of meter reading by power utility companies, aimed at developing and validating a communication method for so-called smart meters. Automated meter reading started out as a way of improving the power utility company’s meter reading efficiency, however together with heightened interest in smart grids today, expectations are high for its future potential applications.This paper discusses the scope of NEC support in regards to the validation project until now, as well as efforts toward utilization of smart meters in the future.

Energy devices

SAITO Masahiro

Pyroelectric IR sensors have been used as human detection sensors in security applications because of their low power consumption, non-requirement of peripherals, possibility of human/object differentiation, and simplicity of wiring and signal processing circuitry. They are recently being applied as power conservation measures and for improving comfort and convenience by switching equipment operations based on the detection of human presence/absence. At the present time sensors incorporated in electronic equipment are subject to needs that were not previously relevant, such as compatibility with surface mounting as well as reflow soldering optimized for mass-production, a low sensor profile and resistance to the effects of vibrations and signals generated by other devices in the equipment. This paper introduces the pyroelectric sensor as a device that meets these requirements.

IWASA Shigeyuki ・YASUI Motoharu ・NISHI Takanori ・NAKANO Kaichiro

The organic radical battery is a secondary battery using a plastic material containing stable radicals. It charges and discharges by the oxidation and reduction of radical species such as a nitroxyl radical. This battery features a high-power discharge capability and a flexible structure. In a high-power pulse discharge test, the thin organic radical battery presented no degradation in cell resistance even after 10,000 times of continuous pulse discharge (1-second pulses). The thin and flexible organic radical battery is considered particularly suitable for supplying power to compact ubiquitous devices in the future such as the highly functional smart card.


NEC is attempting to develop electronic equipment featuring both convenience and without standby power consumption by means of non-volatile logic technology using spintronic devices. NEC also expects that applying this technology in the wireless sensor terminals used for example in energy management systems will extend the battery replacement intervals significantly and thereby render the systems virtually maintenance-free.

General Papers


To achieve the top level of efficiency in the market of LED (Light-emitting Diode) household ceiling lights, NEC Lighting has developed a stylish LED ceiling light that matches various interiors. Recently developed, this equipment employs LEDs featuring a superior energy saving performance for the light source. It also introduces a technology that illuminates the entire device equally even to the center of the product, a function that was only achieved hitherto by the conventional fluorescent lighting equipment.

KAMADA Hiroyuki ・YAMAUCHI Hideaki ・SAITO Yoshihiro ・TABATA Tsubasa

Recently, the decrease in voltage and the increase in the current demand of mobile notebook PCs have led to more importance being placed on improving the power loss characteristic. In order to meet this trend, NEC TOKIN has developed the MPCG series of integrally molded choke coils that feature improved power conversion efficiency by the use of a low-loss magnetic core material called “Senntix.” The series achieves a high-current energization capability and a significant reduction in core loss. It incorporates a flat rectangular conductor coil that is wound edge-wise and is fabricated with “Senntix” in a one-piece construction format. It is likely that the power load to the power supply system of electronic equipment will continue to increase in the future. We therefore intend to expand the product lineup and enhance the specifications of the MPCG series and to position them as optimum solutions for electronic equipment energy saving countermeasures by suppressing the amount of heat generated and improving their power integrity.

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