A (10) | B (1) | C (9) | D (15) | E (8) | F (3) | G (5) | H (3) | I (8) | K (2) | L (4) | M (11) | N (6) | O (3) | P (16) | R (6) | S (10) | T (5) | U (1) | W (6) | Z (1)
Term Definition

A term used in siting and permitting for the construction of structures that refers to the distance from the base of the structure to existing easements, roads, buildings, bodies of water, or other geographic or man-made structures or property lines.


Setbacks refer to permitting regulations for the distance from homes and property lines. A county may impose setbacks for a variety of reasons and the requirements may vary depending on the specific land uses. Many setbacks are established generally to protect the available wind resource to encourage wind development while also addressing concerns of homeowners and community members regarding noise, safety, and aesthetics.

Shadow Flicker

Shadow flicker occurs when the blades of the turbine rotor cast shadows that move across the ground and nearby structures.

Signal Interference

As wind energy technology and project siting practices have advanced, the interference with radio, television, cellular, and other broadcast services has been minimized. However local ordinances may require a study of potential impacts to broadcasting services prior to receiving a permit or a listing of such broadcast towers within a certain radius.


Some counties require signs for safety reasons in their permitting regulations, while some also regulate what type of non-safety related signs are allowed. Many ordinances require wind projects to comply with the National Electric Code which already requires high-voltage warnings if necessary, and posting of emergency contact information.

Sound Power

Strength of a sound source, measured in A-weighted decibels (LWA). Typical sound power values for wind turbines (which can be obtained from the turbine manufacturer) are in the range of 90-105 dB(A), LWA. (The measurement is A-weighted to account for the sensitivity of human hearing.)

Sound Pressure

Sound level measured at a receptor (e.g., a neighbor’s house, a microphone). Sound pressure decreases proportionately to the square of the distance from the source and can be affected by prevailing wind direction, topography, temperature, barometric pressure, and other factors. Sound pressure, like sound power, is given in A-weighted measurements (Laeq) to account for the sensitivity of human hearing.

Southern Minnesota Municipal Power Agency (SMMPA)

SMMPA is a company that generates and sells wholesale electricity, primarily for its eighteen member municipally-owned utilities. The member municipally-owned utilities are located mostly in Southeastern and South-central Minnesota. SMMPA website: www.smmpa.com


Permitting regulations in this category address the internal spacing between wind turbines in a given project. There may be a variety of reasons for this type of regulation including ensuring one turbine will not damage another if it malfunctions, or to mitigate impacts on migratory birds and bats. Many developers will already include such internal spacing in their project plans to ensure that each turbine has sufficient wind resource availability since there are significant costs and considerations with decommissioning a project if it is unsuccessful.

System Benefits Charge (SBC)

A required fee (also known as a public benefits charge) from all electricity customers to fund programs that are in the public interest that may or may not be competitive in a deregulated electricity market. These programs include energy conservation, support for renewable energy use, subsidies for people with low-income, and research, development and pilot project construction for new technologies.