The Diablo Winds Energy Project is located in Alameda County California. The project was completed in February 2005 and consists of 31 Vestas V47 turbines located on the Elworthy property in the central portion of the Altamont Pass Wind Resource Area. These turbines replaced 169 FloWind model F-17 and F-19 vertical axis turbines. The vertical axis Flowind turbines were removed in 2004, as were approximately 8 miles of overhead electrical line, one guyed 30-m (98-ft) met tower, and 36 18-m (60-ft) free-standing lattice met towers.
The 660-kW-rated Vestas V47 turbine is an up-wind, 3-bladed, horizontal axis machine mounted on a steel tubular tower with neutral gray or white non-reflective coloring (Figure 1). The Vestas turbine has a rotor diameter of 47m (154ft). The hub height for 24 of the turbines is 50m (164ft, Turbines 1-24) and the remaining 7 turbines have a hub height of 55m (181ft, Turbines 25-31). The maximum height to the rotor tip when in the 12 o’clock position is 73.5m (241ft) for the shorter 24 turbines with 50m towers, and 78.5 m (258ft) for the remaining 7 turbines on the 55m towers. The blades rotate at 28.5 rpm at wind speeds between 6 and 56 mph. Electrical and communication cables are placed underground. The project included two 50-m (164-ft) selfsupporting anemometer towers.
This progress report summarizes results of the avian and bat monitoring program for the Diablo Winds Repowering Project in Alameda County, California for March 2005 through February 2006. A final report that includes the first two complete years of monitoring will be completed in April 2007. The final report will include more detailed statistical analyses and discussion.