Wind energy vs. wind energy - Solar, Wind and Land: Conflicts in Renewable Energy Development - page 60

Predominant
wi nd direc tion

Parcel D

Parcel U

Property
line

Safety
setbacks

Figure 3.3 Hypothetical turbine layouts for parcels U and D when designed by
two independent developers

would claim that Upwind Developer's layout unreasonably interfered with
Parcel D's wind rights and might seek an injunction to prevent Upwind
Developer from using its layout or damages for the losses resulting from it.
In Minnesota, this sort of conflict would not arise at all. In that state,
“wind access buffer” setbacks of five rotor diameters on the predominant
wind axis and three rotor diameters on the secondary axis would disallow
both developers' proposed turbine layouts. 29 Such setbacks are relatively
effective at preventing turbine installations in locations that are close
enough to parcel boundaries to generate wake-related disputes.
However, these sorts of well-intended setback restrictions can also greatly
reduce the amount of developable wind energy land within a jurisdiction.
The potential inefficiency of this approach is illustrated in Figure 3.4 . A
wake-based setback imposed on the relatively small parcels used in the
fact pattern above would require both of the developers in the fact pattern
to scale back their turbine layouts to just five turbines each—a 50 percent
aggregate reduction in aggregate wind energy generating capacity from what
would have been possible under the Figure 3.2 configuration. Even when
only one or two optimal turbine sites are precluded due to such setback
rules, the resulting inefficiencies are often likely to exceed those that would
have resulted under the absence of a setback rule. At least one renewable
energy developer has commented that such a setback requirement would
threaten the economic feasibility of its wind project. 30
Given the significant inefficiencies associated with wake-based setbacks,
it is hardly surprising that multiple groups expressed disapproval when
the Minnesota Public Utilities Commission first considered imposing its