William & Mary Environmental Law and Policy Review


Developers of onshore, utility-scale wind farms seek to purchase or lease parcels on which commercial wind turbines will be sited, carefully selecting each particular parcel based on its access to high wind speeds and unobstructed wind flowing across it in the free stream. Accordingly, a wind farm developer’s purchase or lease of a tract of land generally entails a large monetary investment and carries with it an investment-backed expectation that such land will be used for its originally intended purpose. Wind wakes, which disrupt the wind velocity in the free stream, cause downwind turbines to encounter diminished wind speeds and turbulence, as well as experience structural fatigue and stress. Collectively, these factors can substantially reduce these downwind turbines’ originally projected energy output over the course of their operational lives. When wind wakes generated from wind turbines on an immediately adjacent neighbor’s property extend over a downwind neighbor’s land, that land will experience wake-related adverse impacts. As a result, wind turbines that are already in place, or which are scheduled to be erected, on the downwind parcel may experience wake effects from its neighbor’s upwind turbines. Purchasing or leasing land that experiences wake-related adverse impacts can deprive a wind farm developer of the opportunity to realize its investment-backed expectation, translate into millions of dollars of future lost income, and render the parcel at issue effectively useless in terms of the original purpose for which it was obtained. This Paper provides an overview of wake effect–related matters wind farm developers and other prospective purchasers should consider in their respective decisions regarding land purchasing and leasing, wind turbine siting and placement, rights associated with wind flow across a particular parcel, and measures that can be taken to legally protect such rights. First, it presents a brief scientific overview about wind wakes and describes why they are important considerations with respect to land purchasing or leasing, particularly with respect to legally mandated setback requirements. Second, it provides background about other countries’ legal precedent and U.S. precedent for whether a federally recognized property right to unobstructed wind flow over a landowner’s parcel exists. Third, it discusses how safety concerns, not generally accepted scientific concepts relating to wind wakes and wake effects, are used to establish setback limits for commercial wind turbines from shared property lines. Fourth, it provides an overview of notice requirements and the establishment of entitlements under the Fourteenth Amendment’s Due Process Clause, including why a right to wind flow across one’s property may be deemed an entitlement. Fifth, it discusses legal rights that may be protected between parties by such parties entering into legal contracts. Additionally, it uses a recently litigated California case, Wind Energy Partnership et al. v. NextEra Energy Resources LLC et al., to illustrate real-world issues associated with wind wakes. These issues include due process and public policy considerations, such as why it may be financially detrimental to downwind landowners or downwind developers if they do not consider adequately the types of actions that may constitute adequate notice, the timing of government hearings for actions impacting the land at issue and these hearings’ significance, the temporal significance of land ownership, as well as the short-term and long-term goals of the local community. Finally, it suggests measures that landowners and developers should take as a matter of best practices to establish and secure legal protection of their wind rights.