Solar Energy Operations Impacts
Operations activities that may cause environmental impacts include operation of the solar energy facility, power generation, and associated maintenance activities.
Typical activities during the solar energy facility operations phase include operation of the solar energy facility, power generation, and associated maintenance activities that would require vehicular access and heavy equipment operation when components are being replaced. Potential impacts from these activities are presented below, by the type of affected resource.
The following potential impacts may result from solar energy operations.
Sources of noise during operations would be mechanical and aerodynamic noise from the power block (depending on the solar technology used—such as from steam turbine generators, pumps, cooling towers), solar tracking devices, solar dish engines, transformer and switchgear noise from substations, corona noise from transmission lines, vehicular traffic noise, and maintenance facility noise.
Air Quality (including Global Climate Change and Carbon Footprint)
There are no direct air emissions from operating a solar facility. Minor volatile organic compound (VOC) emissions are possible during routine maintenance activities, such as mirror washing or mirror replacement. Vehicular traffic will continue to produce small amounts of fugitive dust and tailpipe emissions during the operations phase. Depending on the solar technology used, some power block emissions are possible from process boilers (combustion-related criteria pollutants and hazardous air pollutants [HAPs]) and cooling towers (small amounts of particulate matter). These emissions would not likely exceed air quality standards nor have any impact on climate change.
Impacts during the operations phase would be limited to unauthorized collection of artifacts, and visual impacts. The threat of unauthorized collection would be present once the access roads are constructed in the site evaluation or construction phase, making remote lands accessible to the public. Visual impacts resulting from the presence of large solar facilities and transmission lines could affect some cultural resources, such as sacred landscapes or historic trails.
During operation, adverse ecological effects could occur from (1) disturbance of wildlife by equipment noise and human activity; (2) site maintenance (e.g., washing solar collectors and vegetation control); (3) exposure of biota to contaminants; and (4) mortality of birds from colliding with the project facilities, being burned by concentrated solar rays (primarily for power tower projects, and collisions with and/or electrocution by transmission lines. During operation of a solar energy facility, wildlife could still be affected by habitat fragmentation due to the presence of the fenced solar energy facility, utility rights-of-way (ROWs), and access roads. In addition, the presence of a solar energy development project and its associated access roads and ROWs may increase human use of surrounding areas, which in turn could impact ecological resources in the surrounding areas through:
Possible environmental justice impacts during operation include the alteration of scenic quality in areas of traditional or cultural significance to minority or low-income populations and disruption of access to those areas. Noise impacts and health and safety impacts are also possible sources of disproportionate effect.
Hazardous Materials and Waste Management
Industrial wastes are generated during routine operations (dielectric fluids, cleaning agents, and solvents). These wastes typically would be put in containers, characterized and labeled, possibly stored briefly, and transported by a licensed hauler to an appropriate permitted off-site disposal facility as a standard practice.
Unique to photovoltaic (PV) technologies, some high-performance solar cells may contain small amounts of cadmium, selenium, and arsenic, and are only hazardous if the solar cell is broken. Damaged cells would need to be characterized and managed as hazardous waste.
Concentrating solar power (CSP) technologies (parabolic trough and power tower) may also generate substantial amounts of heat transfer fluids (HTFs) and industrial solid wastes, such as lubricating oils, compressor oils, and hydraulic fluids.
Impacts could result if these wastes were not properly handled and were released to the environment.
Human Health and Safety
Possible impacts to health and safety during operations include exposures to electromagnetic fields (EMF) and accidental injury or death to workers during operation and maintenance activities. In addition, worker health and safety issues include working in potential weather extremes, and possible contact with natural hazards, such as uneven terrain and dangerous plants, animals, or insects. Risk to the public of accidental death or injury is unlikely since the facilities are fenced.
Land use impacts during the operation of the solar facility would be an extension of those that occurred during the construction phase. No alternate land use would be available during the operation of the solar facility, with the possible exception of directional drilling for oil and gas resources.
Impacts during the operations phase would be limited to unauthorized collection of fossils. This threat is present once the access roads are constructed in the site evaluation or construction phases, making remote lands accessible to the public.
Direct impacts would include the creation of new jobs for operation and maintenance workers and the associated income and taxes paid. Indirect impacts are those impacts that would occur as a result of the new economic development and would include things such as new jobs at businesses that support the workforce or that provide project materials, and associated income and taxes. The number of project personnel required during the operation and maintenance phase would be about an order of magnitude fewer than during construction. Therefore, socioeconomic impacts related directly to jobs would be minimal.
Soils and Geologic Resources (including Seismicity/Geo Hazards)
During operation, the soil and geologic conditions would stabilize with time. Soil erosion and soil compaction are both likely to continue to occur along access roads. Within the project footprint, soil erosion, surface runoff, and sedimentation of nearby water bodies will continue to occur during operation, but to a lesser degree than during the construction phase, and the impact is expected to be small once equilibrium is achieved.
No noticeable impacts to transportation are likely during operations. Low volumes of heavy- and medium-duty pickup trucks and personal vehicles are expected for routine maintenance and monitoring. Infrequent, but routine shipments of component replacements during maintenance procedures are likely over the period of operation.
Solar energy development projects would be highly visible in rural or natural landscapes. The disturbed area would continue to contrast with the natural form, line, color, and texture of the surrounding landscape. Visual evidence of a solar field cannot easily be avoided, reduced, or concealed, owing to its size and exposed location; therefore, effective mitigation is often limited.
Additional issues of concern are specular reflection from the solar collector arrays resulting in glint or glare (except for PV arrays); visual contrasts from support facilities, and light pollution from the lighting on facilities.
Additional visual impacts would occur during maintenance from vehicular traffic.
Water Resources (Surface Water and Groundwater)
Withdrawals of surface water and/or groundwater are expected to continue during the operations phase. The amount of water needed depends on the solar technology employed. Impacts to water resources during the operation and maintenance phase would also include possible degradation of water quality resulting from vehicular traffic and machinery operations during maintenance (e.g., erosion and sedimentation) and wastewater disposal.