Wind energy vs. wind energy - Solar, Wind and Land: Conflicts in Renewable Energy Development - page 58

Not only is wind highly unique among natural resources, but disputes over
wind rights are also materially different from any other conflict covered in
this topic. Wind turbine wake interference conlicts do not involve tradeofs
between renewable energy development and some other land use such as
a residential neighborhood, wildlife habitat, or scenic territorial views.
Instead, they pit one renewable energy developer against another in clashes
over the same type of development, often undermining efficiency on both
sides of the property line.
If analogies to water law, oil and gas law, or laws governing rights
in wild animals do not provide satisfactory legal rules for wind rights,
what rules are best suited for allocating wind rights among landowners?
Unfortunately, as described in the following subsections, the basic policy
strategies for dealing with turbine wake interference that have been adopted
to date frequently fall short of the basic goal of maximizing the productivity
of the wind resources involved.
Wake-based setbacks?
Other than Otsego County's “first-in-time” approach highlighted above, the
only significant policy response to the turbine wake interference problem to
date has been to impose wide, wake-based setbacks to prevent such conflicts
from arising. The U.S. state of Minnesota has embraced this approach. In
that state, commercial wind energy developers must site turbines at least
five rotor diameters away from all boundaries of their project control area
on the predominant wind axis and three rotor diameters from boundaries
on the secondary wind axis unless they receive special government approval
to do otherwise. 28 Given that rotor diameters for many modern commercial
wind turbines are upwards of 100 meters, these setbacks essentially prohibit
turbine installations for a half kilometer behind a turbine. Although these
setbacks certainly go a long way in preventing wake interference conflicts,
they can also be sources of significant inefficiency, taking vast sections of
prime wind energy land out of productive use.
To illustrate the disadvantages of using setbacks to govern wake inter-
ference problems, let us return to Parcels U and D described earlier in the
chapter. For simplicity, assume that these are the only two parcels in the
relevant vicinity that have any developable wind resources. Suppose further
that, taking wind speed data and potential wind turbine wake interference
issues into account, the overall turbine layout that would maximize the
aggregate energy productivity of the wind resources on these two parcels
is as shown in Figure 3.2 . If a single developer held development rights
covering both parcels, the developer would choose this layout to maximize
the productivity of the wind resources involved.
An optimal set of legal rules for allocating wind rights would result in
this Figure 3.2 layout, regardless of whether the parcels had been leased
together by a single developer or separately by two competing developers.