Solar - Energy Policy Analysis: A Conceptual Framework - page 108

land disturbance and land use impacts (USDOE, USDOI, and ANL 2011). Use of decentralized
photovoltaic systems instead of central-station solar power towers would reduce the need for such
land disturbance to nothing.
Visual Impacts
Because they are generally large facilities with numerous highly geometric and sometimes highly
reflective surfaces, solar energy facilities, which are often located in rural areas, may create visual
impacts; however, being visible is not necessarily the same as being intrusive. Aesthetic issues
are by their nature highly subjective. Many Americans are increasingly viewing solar photovol-
taic panels as attractive symbols of progress and possible independence from foreign sources of
energy supplies. Again, proper siting decisions can help avoid negative aesthetic impacts on the
landscape (USDOE, USDOI, and ANL 2011).
Water Resources
Parabolic trough and central tower systems typically use conventional steam plants to generate
electricity, which commonly consume water for cooling. In arid settings, increased water demand
could strain available water resources. If cooling water was contaminated through an accident,
pollution of water resources could occur, although the risk may be minimized by sound operating
practices (USDOE, USDOI, and ANL 2011). Concentrating solar systems require water for regular
cleaning of concentrators and receivers and for cooling the turbine-generator. Using water from
underground wells may affect the ecosystem in some arid locations (USEIA 2011e).
Hazardous Waste Disposal
Some solar thermal systems transfer heat by using potentially hazardous fluids that require proper
handling and disposal. Some toxic materials and chemicals, such as silicon tetrachloride, and
various solvents and alcohols are used in the manufacturing process for photovoltaic cells, but no
more (and often less) than are used when manufacturing other energy technologies.
Photovoltaic panels may contain hazardous materials, and although they are sealed under
normal operating conditions, there is a potential for environmental contamination if they were
damaged or improperly discarded upon decommissioning. An Oregon study on the life cycle of
solar panels notes that arsenic, cadmium, and other chemicals are used during construction of
photovoltaic panels, requiring environmentally sensitive disposal. However, pollutant and heavy
metal emissions associated with solar photovoltaic panels are due primarily to raw material ex-
traction and energy consumption during the manufacturing process (Fthenakis, Kim, and Alsema
2008; Oregon Department of Transportation 2008). Cadmium, which is extremely toxic, is used
in very small amounts in cadmium telluride solar cells as a semiconductor to convert solar energy
into electricity. Firms that make these solar cells often have recycling programs so unusable cells
do not inadvertently damage the surrounding environment (USDOE, USDOI, and ANL 2011).
Concentrating solar power systems may employ liquids such as oils or molten salts that may
be hazardous and present spill risks. In addition, various fluids, such as hydraulic fluids, coolants,
and lubricants, are commonly used in most industrial facilities. These fluids may in some cases be
hazardous and present a spill-related risk. Proper planning and sound maintenance practices can
minimize impacts from hazardous materials. As with other industrial applications, waste materials
must be disposed of in licensed waste disposal facilities (USDOE, USDOI, and ANL 2011).