Nikkei BP Japan Technology Report / A1407-060-011 Vehicle-to-Home technology boosting the value of automobiles Keisuke Ogawa Nikkei Automotive Technology Cars aren’t just for driving around in; they can also supply power to the home. This new capability of the automobile, called Vehicle-to-Home (V2H), is now entering commercial use in electric vehicles. Development is also under way for use with plug-in hybrids and fuel-cell vehicles. This new dimension of utility, swapping energy with the home, is something the conventional gasoline engine vehicle simply cannot do, but it could mean significant new value for vehicles. The promise is reducing home electricity bills, and serving as emergency power in times of need. This report examines the V2H initiatives of three major Japanese automobile manufacturers: Nissan, Honda, and Toyota. Nissan already offers commercial V2H service based on its Leaf electric vehicle, while Honda and Toyota are in demonstration trials. Development is well under way for electric vehicles and plug-in hybrids, but sales are minimal for all types except hybrid electrics. It will take time for the fuel-cell vehicles marketed in 2015 by Toyota and Honda to penetrate the market, and likewise to construct a hydrogen fuel infrastructure. Practical V2H system rollout from manufacturers will boost the real value of electric vehicles, and provide impetus for widespread adoption. Nikkei Automotive Technology published by Nikkei Business Publications (Nikkei BP) is Japan’s first comprehensive magazine that devotes editorial content not only to automotive technology updates but also to related engineering areas such as environmental protection, precision and appliances. Its target readers are engineers engaged in research, development and manufacturing of automobiles, automotive parts/materials and facilities. Key advertising clients include manufacturers of electronic and other automobile parts, makers of industrial precision robots for factory use, and developers of measuring components/software. “Nikkei BP Japan Technology Report” is a fee-based publication offering English-language translations of key technical articles selected from the full array of Japanese-language Nikkei BP publications. ( http://techon.nikkeibp.co.jp/english/ ) All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form without the written permission of the publisher. © 2014 1 Nikkei BP Japan Technology Report / A1407-060-011 Vehicle-to-Home (V2H) technology offers a number of merits, including reducing home electricity bills by shifting the peak load, and offering a ready source of emergency power when the grid is down. It would enable consumers to reduce both their demand charge (monthly fixed-rate cost) and energy charge rate (cost per kWh). Supplying the home with power from the vehicle during the noon peak would lower the demand charge, and by recharging it at night it would be possible to take advantage of late-night discount rates to keep the energy charge rate low, too. With functions to change vehicle energy into electricity, the automobile also becomes an emergency power supply for the home during power outages. “Consumer need for V2H systems is clearly rising,” says a source at Nissan Motor Co., Ltd., pointing to the rising number of outages, from the rolling blackouts after the 2011 Tohoku earthquake to natural causes such as typhoons. There are three major firms involved in V2H development: Nissan, Honda Motor Co., Ltd., and Toyota Motor Corp. Nissan already offers a commercial product, while Honda and Toyota are still running demonstration trials. All three systems offer peak reduction and energy supply (regular and emergency use), but each manufacturer has a slightly different design, in terms of system configuration, output, and supply capacity (Fig. 1, Table). A variety of electricity generating systems are already available, including solar power, home-use storage systems, fuel cells, and fuel gas generators. By introducing V2H Fig. 1 Fundamental V2H technology A power conditioning system (PCS) converts DC to AC power for supply to the home. Different automobile manufacturers position the PCS in different places, and use different connectors. © 2014 2 Blanc page for sample Nikkei BP Japan Technology Report / A1407-060-011 The inverter box is mounted in the middle of the load space (Fig. 5). They decided to supply 6 kW to home use because that would be sufficient for most household requirements, and because existing charging systems could be connected directly to the inverter box. “It would cost too much to make new connectors and cables capable of handling 9 kW,” explains Okabe, “Using an existing system meant lower cost and improved convenience.” The main change in the vehicle itself is the addition of a CHAdeMO connector. Unlike EVs and PHEVs, FCVs use hydrogen for fuel, so they do not require connectors for regular or fast charging, and a CHAdeMO connector was installed in the load space. The inverter box is plugged into the vehicle’s CHAdeMO connector for DC power directly from the vehicle. Controller Area Network (CAN) communication between vehicle and inverter box ensure safety during output. When used in the home, Honda also provides a switch to select either FCV or grid power, in the same manner as the Nissan Leaf. The switch (installed in the distribution board) can be controlled via wireless using a dedicated tablet app. As with the Leaf, the FCX Clarity uses its power supply capability to shift the peak load in the home. It will still take some time to get the hydrogen infrastructure in place, Fig. 5 Honda’s power conditioning system (PCS) (a) Maximum output is 9 kW: 3 kW to direct receptacles, and 6 kW to the home. The CHAdeMO connector, newly added for V2H, connects home and vehicle for power supply. (b) System configuration. A junction box plug in the home is connected to the PCS when using V2H. © 2014 8 Nikkei BP Japan Technology Report / A1407-060-011 though, and the price of hydrogen for FCVs is still unsettled. Given these uncertainties, the strongest sales point at present would seem to be its utility as an emergency power source. Honda plans to launch volume production of FCVs in 2015, and intends to provide them with V2H connectors. The firm is now considering providing inverter boxes to corporate users only to start. Because FCVs will need major improvements in the hydrogen supply infrastructure, volume-production V2H products for the private user “are targeted for 2025 - 2030, some ten or fifteen years from now,” says Okabe. Toyota Works in Combination with Home Storage Batteries The Toyota test vehicle is a Prius PHV (a PHEV design), modified to add electricity supply capabilities. The onboard battery capacity is a relatively small 4.4 kWh, so output has been cut back to only 1.5 kW, considerably less than the Leaf or the FCX Clarity. This low output is bolstered by first storing the energy in the home storage system, and then supplying it from there through the distribution board to the home as needed (Fig. 6). There are two merits to this approach, the first of which is that since the home storage system is used, the vehicle PCS can be much smaller and cheaper. The second advantage is that even if the power from the vehicle is unstable, the electricity provided Fig. 6 Toyota’s V2H system, now being trialed (a) Electricity from the Prius PHV is output through the regular charging connector and stored in the home storage battery. (b) In normal use, power from the vehicle is stored to the battery first, and used from there. © 2014 9 Blanc page for sample Nikkei BP Japan Technology Report / A1407-060-011 will be difficult to recover initial investment through peak load cutting alone. Since buildings are expected to serve as emergency facilities, however, V2B represents a viable option requiring consideration separate from simple investment recovery. The personal computer sited in the parking area monitors output, voltage, current, and charging state for each Leaf (Fig. B), using data acquired via the CHAdeMO connector while supplying power to the facility. Fig. B V2B central management system External charging status for each EV can be checked on the computer screen, with data on battery charge, output, and other items available for individual vehicles. Your feedback is important to us, please feel free to respond with any comments or questions. http://techon.jp/JTR/feedback/ Nikkei Business Publications is a cross-media company in Japan that provides businesspeople with high value-added information on management, technology, and life. First established as a group company of Nikkei, Inc. in April 1969, Nikkei Business Publications has grown into one of the largest providers of cutting-edge information, content, and services in the specialized fields. In addition to the primary business in print and online, we offer an array of businesses and services, such as exhibitions, seminars, customized publishing, research, and consulting, to meet a variety of client needs. For more information, please visit our website : http://www.nikkeibp.com/ © 2014 13
© Copyright 2024 ExpyDoc
