As always, TVA still refuses to provide timely or detailed information regarding the performance of their wind power plant, even when requested under the Freedom of Information Act.
After last report's unprecedented reporting of data on the same date as a previous year, TVA returned to their previous inconsistent reporting pattern, and even stooped to a new low. This time they reported data for a four month period, the longest period yet, since initial operations from October 2000 through March 2001. Despite the efforts to obscure the data, simple interpolation between July and October 2002 (during the low production period) yields the following results.
Annual energy production from August 31, 2002 to August 31, 2003 was approximately 3.66 million kilowatt hours, which is down slightly from last report (3.74 million kilowatt hours, for April 2002 to April 2003). Compare this production with TVA's original announced, annual goal (pre-operations) of 6 million kilowatt hours, and TVA's announced revised annual goal (2002) of 4.6 million kilowatt hours. They need to achieve 27% capacity factor to meet the revised goal.
Despite the extended, four-month reporting period, the capacity factor, at about 13.9%, was about tied for second worst performance reported so far. Average lifetime capacity factor has about stabilized at 20-22%, with the latest value of 21.0%
The interesting question is how often, and for how long at a time, the windmills actually produce zero power. TVA has not released that information to my knowledge, but I was in the vicinity during an obvious zero-power time period this July. I think it occurs more often than one would guess, which is why TVA does its best to hide the data.
