Here's a 2006 study on the effects of a wind farm on property values in NY.

The executive summary says, "Potentially adverse effects of windfarm visibility on property values can represent real costs to communities, yet few studies exist on the subject. The studies that are available are contradictory, and suffer from statistical flaws. A clearer understanding of actual effects of existing wind facilities will inform future decisions. To explore this subject this report analyzes 280 arms-length single-family residential sales using a hedonic regression model.

The sales took place from 1996 to 2005 and are within 5 miles of a 20 turbines - 30 megawatt (MW) windfarm in Madison County, New York. The report differentiates itself from previous studies by visiting all homes (“ground truthing”) in the sample to ascertain the actual level of turbine visibility. The analysis finds an absence of measurable effects of windfarm visibility on property transaction values. This result holds even when concentrating on homes within a mile of the facility and those that sold immediately following the announcement and construction of the windfarm in 2001. These results dispel the proposition that effects, either positive or negative, are universal. The report concludes by making recommendations to stakeholders and outlining possible considerations for further research."

Read the study here.