5.8.
Issue Assessment
Energy Development
Development of energy sources, including alternative energy (such as solar,
wind, geothermal, or biofuels) could pose compatibility issues related to
glare (solar energy), vertical obstruction (wind generation), or water
quality / quantity.
The moving blades of a wind turbine create a Doppler effect that can
interfere with radio transmissions and radar systems. The impacts to radar
are increased with the height, number, and clustering of wind turbines;
however, the greatest impact is caused by their location in proximity to the
radar system. Although research is still being conducted, it is not fully
known how tall, large, or how many wind turbines must be present to
interfere since a radar system may be greatly impacted by even a minor
interference.
Relative to renewable solar energy, solar facilities could cause substantial
amounts of glare depending on their type, location, angle and direction,
resulting in a reduction of a pilot’s view, even at a very high altitude.
Key Terms
Alternative Energy. The term alternative energy is applied broadly to
energy derived from renewable sources (e.g., solar, hydroelectric, wind).
Radio Frequency Clutter. Radio frequency clutter is produced by rotating
turbine blades, which creates an undesired Doppler shift on the radar signal.
This effect can be increased when the density of wind turbines is high.
Screening. Screening refers to the blocking out portions of the radar “field
of view” so that aircraft control instrumentation and / or personnel cannot
see aircraft that fly behind the “screen.”
June 2017
ISSUE
ED‐1
Alternative Energy Development Coordination
There are no formal local procedures for coordinating
alternative energy development proposals with the DOD and
Maxwell AFB.
Compatibility Assessment
Certain alternative energy projects such as solar and wind development can
create incompatibilities with aircraft communications and operations
through their design. Solar and wind energy development is not as
prevalent in Alabama as in some of the neighboring states; however, as the
technology for solar energy evolves, and the cost of attainment decreases,
solar is becoming more practical as an alternative source of energy
production.
Wind energy can impact aviation activities by creating halo effects on radar
making communicating with aircraft between ground control challenging.
This can create false radar readings that make it appear that there are
aircraft flying in the area that are not actually there. Wind energy projects,
typically commercial / utility scale projects, have the potential to affect radar
operations and communications at Maxwell AFB due to interference, which
is dependent upon the height and density of the turbines, as well as their
proximity to Maxwell AFB’s operational areas.
According to the National Renewable Energy Laboratory, there is mild to
moderate potential for wind energy in the Montgomery region, although not
in the immediate vicinity of the City of Montgomery due to its urban
Background Report
Page 5‐37