Harnessing the sun’s energy and converting it to electricity offers one of the most technologically viable and cost-effective means to produce pollution-free, sustainable power. Generating electricity at the scale necessary to move the United States away from dirty fuels requires long-term planning for efficient and responsible project development. Utility-scale solar power (USP) projects are most cost-effective in the arid, sunny Southwest, where much of the land is public land managed by the federal government. Today’s utility-scale solar power technologies and environmental practices ensure that land impact is minimized when these plants are sited.
Abundant Solar Resources
There is tremendous solar power generation potential in the United States. In five minutes, enough sunlight will shine upon the United States to satisfy America’s energy demands for an entire month. The U.S. Southwest has particularly abundant and high quality resources for utility-scale solar power. After screening land for a variety of factors, including urban areas and lands deemed environmentally sensitive, the Department of Energy found that nearly 7,000 gigawatts of solar generating capacity could be installed on 34 million acres of land in just seven states. That’s enough capacity to power 1.4 billion homes.
Depending on the specific technology, a utility-scale solar power plant may require between 5 and 10 acres per megawatt (MW) of generating capacity. Like fossil fuel power plants, solar plant development requires some grading of land and clearing of vegetation. For example, many concentrating solar power (CSP) plants need to be constructed on flat land with less than 1-percent slope. Modular technologies, such as utility-scale photovoltaics (PV), concentrating PV, and dish-engine systems, can utilize land with steeper slopes and no water access.
Benefits of Utility-Scale Land Use
In order to operate most efficiently, and thus most cost-effectively, many USP plants require contiguous parcels of land. In 2005, the National Renewable Energy Laboratory released two reports illustrating how the land necessary for a utility-scale centralized power station lowers costs for consumers:
- Scaling up a parabolic trough plant from 88 MW to 220 MW significantly decreased the levelized cost of energy by more than 2 cents/kWh.
- Building power plants next to each other (in this case a 4x250MW power park) resulted in an additional 10 to 12 percent reduction in the levelized cost of energy.
For solar power plants, which are on the margin of cost competitiveness with conventional power, the combination of these two impacts (especially the former) can make or break a project.
Environmental Review for Utility-Scale Solar
Environmental review of a proposed USP plant on public land can take three to five years. This time period can be lessened if the plant is located on private or previously disturbed land. Many areas ideal for USP development are on public lands overseen by the Bureau of Land Management (BLM) within the U.S. Department of the Interior. The BLM right-of-way (ROW) permits undergo a strict review process before being issued, as required by the National Environmental Policy Act of 1969. Companies provide detailed project construction plans, environmental impact assessments and mitigation strategies. The BLM, in coordination with state and local authorities, conducts analyses of the site and holds public hearings with members of the community to gauge the impact of the project on the area. An official Environmental Impact Statement (EIS) is issued for each project before an official Record of Decision is announced.
Development of the Solar Energy Programmatic Environmental Impact Statement
In December 2010, BLM and the Department of Energy (DOE) released a Solar Energy Development Draft Programmatic Environmental Impact Statement (PEIS) to guide the development of USP projects on BLM-managed lands for the next two decades. In October 2011, BLM and DOE issued a Supplement to the Draft Programmatic Environmental Impact Statement (PEIS) to provide more guidance on the solar energy zones (SEZs) as well as the process for developing solar energy facilities outside the zones.
SEIA filed comments in response to both documents advocating for pending applications to be approved under existing policies; a variance process for solar outside of the zones that is clear and flexible; an expedited process for adopting new zones; and coordination between BLM and transmission planning entities. SEIA expects the Final PEIS to be issued in fall 2012. Read more about Utility-Scale Solar.