Process equivalent to the wind power coefficient obtained with large highefficiency wind generators of the propeller type. The vertical axis Bellshion blade in multiple-stage configuration can be considered to be the most efficient method for large-scale electric power generation. Fig.8: Generation of electricity, rotor speed, wind speed Conclusion The measured performance of the vertical-axis Bellshion blade was not lower than of the horizontal-axis type (propeller type) blades currently used. In Japan, there are many places where the annual average wind velocity in city areas is below 4m/s, making it difficult to produce the required electric power. Bellshion VAWTs could capture lowvelocity winds, Fig. 7: Three-stage vertical-axis Bellshion blades without the noise pollution associated with propeller type HAWTs. A multiple-stage Bellshion VAWT is already installed at the Hachijyojima Island farm in Tokyo for performance assessment through long-term endurance testing and the measurement of electric power generating capacity. The Bellshion VAWT is a clean, CO2–free source of energy that can generate electricity 24 hours a day. It can even be used in an urban area without nuisance and can be available at night time and in poor weather conditions, as long as there is a little wind blowing. More information: www.globalenergy.jp Contact: taniguchi@globalenergy.co.jp Fig.9: One-stage vertical-axis Bellshion blades With the multiple-stage vertical-axis Bellshion blade (figure 9) arrangement, the relation between rotor speed and wind velocity remains relatively constant and the wave pattern for power output is consistent. This could be due to the effect of the inarch ring type arm. A wind velocity of 10.6m/s (instantaneous) yields up to 1,028W of electric power. The tests also showed that an average 651W of electric power is generated for a wind power coefficient that exceeds 0.4 at an average wind velocity of 7.6m/s for 1 minute. This is No40 May 2008 / JEC Composites Magazinehttp://www.globalenergy.jp