Renewable energy technologies generate electricity, fuels, or heat through the use of resources that are continually replenished, such as wind, sunlight, and naturally occurring underground steam and heat. Development of utility-scale renewable energy projects on federal land occurs primarily on lands managed by BLM and, to a lesser extent, on those managed by the Forest Service. Nearly all of the approximately 248 million surface acres of federal land managed by BLM are located in 11 western states and Alaska. BLM is also responsible for managing resources (e.g., geothermal, oil, and gas resources) lying on or beneath federal lands and beneath private lands for which the federal government retains mineral rights—amounting to approximately 700 million subsurface acres altogether. The Forest Service is responsible for managing 193 million acres of forests and grasslands, primarily in the western states but also throughout the country. The Fish and Wildlife Service and National Park Service manage about 90 million and 80 million acres, respectively, but under legislation that generally precludes the development of large-scale renewable energy projects. Another Interior agency, the Bureau of Indian Affairs, works with Indian tribes to develop renewable energy on tribal lands. Renewable energy projects on federal lands date back decades; for example, utility-scale geothermal projects have operated on both BLM- and Forest Service-managed lands since the 1970s, and several utility- scale wind projects have been operating on BLM-managed lands, primarily in California, since the early 1980s. In May 2012, the first utility- scale solar power plant began operating on federal lands, specifically on BLM-managed land. No utility-scale wind or solar development is operating at present on Forest Service-managed lands. In general, over half the nation’s electricity generated from geothermal resources comes from resources on federal lands, and about 1 percent of the nation’s electricity generated from wind and solar energy comes from resources on federal lands. Electricity generation using wind, solar, and geothermal energy can range from small-scale production—for example, rooftop solar panels on a home or geothermal resources heating a greenhouse—to utility-scale production of hundreds of megawatts of electricity. Figure 1 shows examples of utility-scale facilities representing each of these three energy types. The most common technologies for utility-scale wind, solar, and geothermal development include the following: Wind energy. Wind farms comprise a number of turbines built close together to produce utility-scale wind power. Horizontal-axis turbines, the most common, constitute nearly all utility-scale turbines in the United States. To generate electricity, horizontal-axis turbines capture the wind’s energy with two or three propellerlike blades mounted on a rotor sitting atop a tower. A smaller utility-scale wind farm may have 6 turbines on 100 acres and generate about 3 megawatts, and a larger wind farm may have over 100 turbines on about 10,000 acres and generate over 300 megawatts. Siting wind farms in appropriate locations is important because they can fragment wildlife habitat and plant communities, and the turbines and blades themselves may kill birds and bats, make noise, and mar views. Solar energy. Multiple technologies exist for utility-scale solar power. Solar photovoltaic technologies convert energy from sunlight directly into electricity, using arrays of solar panels. Concentrating solar power technologies use mirrors to focus the sun’s energy to heat water or other fluids; these fluids in turn create steam that powers a conventional turbine generator to produce electricity. An average solar plant, whether photovoltaic or concentrating, requires about 3 to 8 acres for every megawatt of generating capacity. For example, a small utility-scale solar plant occupying about 400 acres may generate 45 megawatts, and a large facility occupying over 7,000 acres may generate 1,000 megawatts. Selecting appropriate areas for the development of solar projects is essential given that such development generally precludes other uses of the same land because the surface area is graded before installation, and components are installed relatively close to one another. In the southwestern United States, where the potential for solar energy development is greatest, solar installations can affect habitat needed by various species, including those listed as threatened or endangered under the Endangered Species Act, such as the desert tortoise. In addition, some solar technologies use large amounts of water, which can be problematic in desert environments. Geothermal energy. Geothermal power plants extract geothermal fluids—hot water, brines, and steam—from the earth by drilling wells to depths of up to 10,000 feet. These fluids are then used to create a vapor that can power a turbine generator to produce electricity, with only the highest-temperature geothermal resources—generally above 200 degrees Fahrenheit—suitable for electricity generation. Geothermal power plants typically generate from 30 to 120 megawatts, and an individual power plant often uses resources brought to the surface through multiple wells. Mitigating for harmful effects is important in geothermal planning because geothermal operations can emit dangerous gases, and geothermal drilling operations may contaminate groundwater. However it is generated, electricity from utility-scale renewable energy development is sold to utilities and—like electricity generated by more conventional sources such as coal- or gas-fired power plants—is conveyed to consumers through transmission lines. Some of the best locations for wind and solar development, however, are in remote areas far from consumers, and transmission lines to carry the power are not always readily available in these remote areas. In addition, electricity generated from wind and solar development differs from geothermal and conventional sources because it is available intermittently, rather than continuously. In managing their lands, BLM and the Forest Service are required by the Federal Land Policy and Management Act of 1976 and the National Forest Management Act, respectively, to develop or revise land use plans for the areas they manage, providing for multiple uses, such as recreation, timber, and fish and wildlife, and natural scenic, scientific, and historical values. All land management actions, including renewable energy development, must conform to the approved land use plan governing the land management unit—such as a national forest—where the action is to take place. Consequently, renewable energy development can occur only where it is consistent with the applicable land use plan, which in some cases may require changing the plan. Plan revisions undergo extensive environmental analysis before being finalized. Wind and solar energy projects on federal land require permits from the relevant land management agency through the issuance of rights-of- way. A right-of-way is an authorization to a qualified individual, business, or government entity to use a specific area of federal land for a specific amount of time for a certain purpose and with certain restrictions. Geothermal activities are administered by BLM for all federal lands (regardless of whether the surface land is managed by BLM or another agency) through the issuance first of leases and then of subsequent permits for drilling operations and other activities—similar to the process used for oil and natural gas. The Federal Land Policy and Management Act of 1976 authorizes BLM and the Forest Service to issue rights-of-way over federal lands for a variety of purposes, including systems for generating, transmitting, and distributing electric energy. For new projects that may have a significant impact on the environment, the act requires applicants to submit a plan of construction, operation, and rehabilitation for the right-of-way that complies with applicable laws and regulations. An agency may issue a right-of-way only after the applicant has demonstrated that it has the technical and financial capability to construct the project for which the right-of-way is requested. Each right-of-way must include terms and conditions that, among others, protect the environment, federal property and economic interests, and the public interest. The holder of a right-of- way must generally pay its fair market value annually in advance and must provide a bond ensuring that the holder can perform the obligations—such as reclamation—required by the terms of the right-of- way. BLM’s permitting process for wind or solar energy projects comprises several steps prior to right-of-way issuance, as follows: A potential project developer contacts the BLM office responsible for land where a right-of-way is sought and obtains a standard application form. Preapplication meetings take place between the potential applicant and appropriate BLM field office staff to discuss the application form and its requirements, the general project proposal, land use planning in the area, and potential land use constraints. Once an application has been submitted, BLM reviews it to determine whether it is complete. A complete application must include a statement of technical and financial capability to construct, operate, maintain, and terminate the system for which the right-of-way is being requested, along with a project description—called a plan of development—sufficiently detailed for BLM to evaluate the proposed project’s appropriateness and feasibility. BLM checks to ensure that the proposed use conforms with BLM land use plans and that no apparent conflicts exist, such as other valid rights for the same lands requested in the application. BLM establishes a cost-recovery fee based on the amount of time BLM estimates it will take to process the application and issue a decision and collects this fee from the applicant. BLM begins processing and evaluating the application, including associated environmental reviews under the National Environmental Policy Act (NEPA), Endangered Species Act, and others. An approved application generally results in an authorized right-of-way, although BLM generally issues a notice to proceed before the holder of the right-of-way can begin construction. On the other hand, BLM is authorized to deny applications for various reasons—for example, if the project is not consistent with the relevant land use plan or if applicants do not provide BLM with sufficient information. At any point in the process, an applicant may choose to withdraw the application. The Forest Service issues permits for wind and solar energy development under its “special use” permit process.