An edited version of this article appeared in the Winter 1999 issue of WindStats Newsletter (Vol. 12, No. 1).
The accompanying tables report data on the performance of Enron Wind Development Corp.’s Zond Z40a and Zond Z40b turbines. The data on the project near Fort Davis, Texas was provided by Central & Southwest Corp. The data on the project near Searsburg, Vermont was provided by the Electric Power Research Institute. Capacity factor and specific yield in kWh/m2 were derived by WindStats from the data provided.
Twelve Z40a turbines were installed in Texas. They use a 40 meter rotor with aileron control. The turbines were first brought on line in September 1995. Central & Southwest did not take control or “accept” the project until July, 1996, nine months after installation. CS&W is an electric utility serving four states including Texas and Oklahoma.
During the 1996 calendar year the turbines at Fort Davis generated 8.4 million kilowatt-hours for a capacity factor of 0.17 and a specific yield of 555 kWh/square meter of rotor area. Performance improved slightly in 1997 and again in 1998. In three calendar years (1996, 1997, and 1998) the turbines produced, on average, a capacity factor (plant factor) of 0.16 and yielded 568 kWh/square meter of swept area.
Eleven Z40b with full-span pitch control were installed in Vermont during the winter of 1996 for Green Mountain Power. The utility accepted the project in July, 1997, nearly eight months after the turbines were installed.
During 1998, the first full calendar year of operation, the turbines in Vermont generated 13.3 million kilowatt-hours, reports EPRI. The turbines produced a capacity or plant factor of 0.25 and a specific yield of 884 kWh/m2 for the year.
Z40b turbines have also been installed in Ireland and China. These turbines use variable pitch for rotor control. No information on the performance of Enron Wind turbines in these projects is publicly available. Notes: 1. The energy production numbers shown above are the number gathered for research purposes and are not net of consumption by control facilities and other electrical losses which much be accounted for in determining the energy delivered to the substation. C&SW
Notes: Data provided by EPRI. Capacity Factor and Specific Yield are derived from production data supplied by EPRI. The energy production numbers shown are the number gathered for research purposes and are not net of consumption by control facilities and other electrical losses which must be accounted for in determining the energy delivered to the substation.
