Materials Transactions Online

Materials Transactions, Vol.47 No.03 (2006) pp.913-922
© 2006 The Japan Institute of Metals

Eco-Efficiency (Factor X) for Electrical and Electronic Products and a Case Study on Home Appliances in a Household

Taeko Aoe

Matsushita Electric Industrial Co., Ltd., Osaka 571-8501, Japan

Many institutes and companies are currently researching into eco-efficiency and Factor X as evaluation methods for environmentally conscious design. However, no standard method has been established. Moreover while the eco-efficiency of each home appliance is being improved, the increasing number and size of such home appliances may increase the overall environmental impact. This paper begins with describing a practical eco-efficiency (Factor X) indicator developed to evaluate environmentally conscious products or services. This indicator gives a rationalized relationship between their functional performance and environmental impacts. Next, the paper presents a brief case study of Factor X done in Japan that compared home appliances from 2003 with those from 1990 using such indicators. The number of home appliances used in a household increased 1.2 times from 65 to 79. However, GHG (greenhouse gas) emissions per year was 0.64 times the former amount, dropping from 8456 to 5383 kg–CO2eq/year, and the new resources and discarded resources per year became 0.99 times the previous amount, dropping from 231 to 228 kg/year. Therefore, GHG Factor X was 1.9 and Resource Factor X was 1.2. Although based on a restricted evaluation model, these results quantitatively show the potential to improve functional performance (as evaluated by the number of home appliances) and at the same time reduce their environmental impacts (as evaluated by GHG emissions and new resources and discarded resources). These results also show that Resource Factor X is more difficult to improve than GHG Factor X. Improving Resource Factor X and establishing a sound material-cycle society requires not only technological innovation and reform of the social system, but also a significant change in people's awareness.

(Received 2005/6/15; Accepted 2006/1/27; Published 2006/3/15)

Keywords: eco-efficiency, Factor X, home appliances, global warming, resources

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  1. L. D. DeSimone, F. Popoff and the World Business Council for Sustainable Development (WBCSD): Eco-efficiency—The Business Link to Sustainable development—, (MIT, 1997) pp.~69–120.
  2. H. A. Verfaillie and R. Bidwell: measuring eco-efficiency—a guide to reporting company performance—, World Business Council for Sustainable Development (WBCSD), (2000) pp.~8.
  3. F. Schmidt-Bleek: Wieviel Umwelt braucht der Mensch?, (Birkhäuser, 1994) pp.~185–206.
  4. E. U. von Weizsäcker, A. B. Lovins and L. H. Lovins: Faktor Vier: Doppelter Wohlstand halbierter Naturverbrauch—Der neue Bericht an den Club of Rome—, (Droemer Knaur, 1995, 1996) pp.~17–34.
  5. R. Yamamoto: Eco-Design Best Practice 100 (in Japanese), (Diamond, Inc., 1999) pp.~55.
  6. R. Yamamoto: Sustainable Company (in Japanese), (Diamond, Inc., 2001) pp.~97.
  7. L. Reijnders: J. Industrial Ecology 2 (1998) 13–22.
  8. P. Saling, A. Kicherer, B. Dittrich-Krämer, R. Wittlinger, W. Zombik, I. Schmidt, W. Schrott and S. Schmidt: Int. J. Life Cycle Assessment 7 (2002) 203–218.
  9. D. R. Shonnard, A. Kicherer and P. Saling: Environ. Sci. Technol. 37 (2003) 5340–5348.
  10. P. Pineda-Henson and A. Culaba: Int. J. Life Cycle Assessment 9 (2004) 379–386.
  11. T. Takahashi, K. Ueno, T. Hayashi, K. Nakagawa and T. Oyama: Proceedings of Eco-design 2002 Japan Symposium (in Japanese) (2002) pp.~54–57.
  12. K. Fuse, S. Oikawa and K. Ebisu: Proceedings of the Sixth International Conference on EcoBalance (2004) pp.~259–262.
  13. Hitachi Group: Environmental Sustainability Report (2004).
  14. T. Aoe: Mater. Sci. Forum 426–432 (2003) 3311–3316.
  15. T. Aoe: J. Jpn. Inst. Energy (in Japanese) 84 (2005) 861–871.
  16. T. Aoe: J. Jpn. Inst. Energy (in Japanese) 84 (2005) 1001–1011.
  17. R. U. Ayres and A. V. Kneese: Am. Econ. Rev. 59 (1969) 282–297.
  18. H. Yoshikawa: Direction to Technologies (in Japanese), (Iwanami, 1996) pp.~66.
  19. T. Aoe: Proceedings of Eco Design 2003, Tokyo (2003) pp.~644–649.
  20. T. Takahashi and K. Ueno: Proceedings of Eco Design 2003, Tokyo, (2003) pp.~747–753.
  21. T. Aoe and T. Michiyasu: Mater. Trans. 46 (2005) 2561–2566.
  22. Japan Environmental Management Association for Industry: Software of JEMAI-LCA Ver.~1.01.


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