The technical potential for clean energy deployment on BLM and other federal lands in the lower forty-eight United States
This blog is the second in a two-part series on the role of federal land management in the U.S. clean energy transition. The first blog, “Improving clean energy infrastructure deployment on federal lands,” focused on current rulemaking efforts. This second post presents the findings of an analysis of technical potential for solar, wind, and geothermal deployment on Bureau of Land Management (BLM) and other federal lands.
The United States needs to increase the pace and scale of clean energy deployment, and fast. Federal lands may hold more opportunity than previously considered.
The United States needs to significantly increase the pace and scale of clean energy deployment to address climate change. Federal lands represent one piece of the complex patchwork of the clean energy siting puzzle. To assess the potential scale of the clean energy opportunity on federal lands, CATF conducted a high-level analysis of the technical potential for wind, solar, and conventional geothermal deployment on the Bureau of Land Management (BLM) and other federal lands. We then compared our estimate to the existing target of 25 gigawatts (GW) of authorized clean energy production on BLM land by 2025. Our results show that considerable headroom exists between the current target and the technical potential for clean energy deployment and suggest that more can be done to responsibly use some federal public lands for the critical public purpose of protecting the climate by decarbonizing our energy systems.
The U.S. Congress adopted a goal in the Energy Act of 2020 for the BLM — an agency in the U.S. Department of the Interior — to authorize production of 25 gigawatts (GW) of clean energy projects on public lands or using federal authorities by 2025. The BLM is actively working toward this goal, but it remains largely alone across the federal land management agencies as the only agency beginning to utilize these vast federal public lands explicitly for energy system development. We asked, is there adequate technical potential to support setting a more ambitious target after 2025? And what could other agencies’ land holdings contribute to the effort to permit wind, solar, and geothermal energy development?
CATF’s analysis shows that the technical potential exists for BLM and other federal land management agencies to increase the ambition of their clean energy goals. What is the magnitude of the opportunity? About 28% of the 2.27 billion acres of land in the United States is public land managed by the federal government. Over a third of that total — roughly 222 million acres — is in Alaska. Although some public lands that are managed for a specific purpose, including national parks, national monuments, or wilderness areas, are appropriately off-limits for most new energy infrastructure, a substantial portion of federal government owned public land is managed for uses that can include clean energy deployment.
These public lands present important opportunities to host clean energy infrastructure development or to manage ecosystems as carbon sinks and for climate resilience. While the missions and authorities for federal land management agencies vary, many have already taken or are exploring actions for climate change mitigation and adaptation on these lands.
Our analysis focused on estimating the technical potential for wind, solar, and geothermal development within the lower 48 states managed by four federal agencies — the Bureau of Land Management (BLM), the Bureau of Reclamation (USBR), the Department of Defense (DOD), and the U.S. Forest Service (USFS). We selected these agencies because they are particularly well-suited for clean energy. Notably, this analysis depicts the one set of technologies encompassed by the Energy Act of 2020 (wind, solar, and geothermal), and does not consider opportunities for other clean firm power development on federal lands.
- The Bureau of Land Management manages the largest amount of federal land at about 245 million acres in total — around 10% of the land area of the contiguous United States — under a multiple use authority with a long history of energy development. The agency also manages the subsurface federal estate. The agency has already started to permit wind, solar, and geothermal energy projects in accordance with their 25 GW by 2025 goal.
- The Department of Defense also controls significant tracts of public land in the United States with high technical wind, solar, and geothermal energy resource potential. DOD lands can present unique challenges for energy system infrastructure siting because of the purposes that the lands are used for compared to the other agencies mentioned here, but also unique opportunities to supply local clean energy alternatives to satisfy existing energy demand on DOD land. Note that the analysis here includes all lands managed by DOD, including those managed by the U.S. Army Corps of Engineers.
- The U.S. Forest Service manages significant tracts of public land in the United States, many with high technical wind, geothermal, and solar energy resource potential. The agency also has a similar multiple-use mission to the BLM; however, to date, the USFS has not taken as many steps to permit energy development projects.
- The Bureau of Reclamation has a mission primarily to manage water resources but was included because it also manages significant acreage across the western United States.
Note: two states (Hawai’i and Alaska), as well as Puerto Rico, were excluded from this analysis for two reasons: (1) they were not included in the data of resource potential estimates, and (2) Alaska’s vast acreage would skew many of the estimates, particularly for BLM.
CATF’s high-level analysis of the technical resource potential leveraged input data from the Net-Zero America Project at Princeton University for technical wind and solar potential based on candidate project areas. The candidate project areas from the Net-Zero America study are based on over 50 inputs established by the Net-Zero America team. The resulting candidate project areas represent only a fraction of the total federal landholdings for all four federal agencies (see Table 1 below). The methodology behind the classification of these candidate project areas is described in greater detail in the Net Zero America Study appendices. These candidate project areas exclude some areas from development that are protected from development or designated areas with “high conservation value” and take into consideration agency-designated areas for siting wind and solar, such as the BLM solar energy zones and priority wind development areas. However, the candidate project areas do not exclude all areas that may be off-limits to clean energy development such as DOD designated training areas, which are not publicly available as spatial data.
The technical potential for shallow (conventional) geothermal is estimated using a public dataset published and made available by Fuchs et al. (2023). One important distinction between these two data sources is that while Net-Zero America does constrain technical potential on some dimensions of practical feasibility, the Fuchs dataset does not account for siting considerations beyond resource potential. The combined estimates for wind, solar, and geothermal also do not account for spatial proximity to existing transmission capacity, demand flexibility for the grid, or future electricity demand — and do not exclude all lands that would be off-limits to development. Therefore, these estimates illustrate the upper bound of technical potential for wind, solar, and conventional geothermal build-out across the acreage identified as candidate project areas. These estimates offer a starting point for assessing the opportunity for responsible clean energy development on federal lands.
More about the data and methodology used in this analysis, including some of the input data assumptions, is available in the technical methodology appendix.
| Agency | Total acres (in the lower 48 contiguous states) | Total suitable acres for solar as % of total reported agency acres | Total suitable acres for wind as % of total reported agency acres | Total suitable acres for conventional geothermal as % of total reported agency acres |
|---|---|---|---|---|
| Bureau of Land Management | 170 million | 48% | 33% | 19% |
| Forest Service | 169 million | <1% | 8% | 13% |
| Department of Defense | 22 million | 4% | 3% | 18% |
| Bureau of Reclamation | 2.1 million | 39% | 42% | 23% |
Using these inputs, we estimated ranges of illustrative technical potential by federal agency (across the four federal agencies). To capture the range in estimated capacity densities by land area, we used both a low and a high (taken directly from the Net-Zero America assumptions) spatial capacity density factor for each technology type (expressed in MW/acre).
| Technology | Capacity density (low) (MW/acre) | Equivalent acres for a 1 MW system (acres) | Capacity density (high) (MW/acre) | Equivalent acres for a 1 MW system (acres) |
|---|---|---|---|---|
| Solar PV | 0.024 | 41.2 | 0.182 | 5.5 |
| Wind | 0.004 | 247.1 | 0.011 | 91.5 |
| Conventional Geothermal | 0.055 | 18.3 | 0.328 | 3.1 |
When estimating spatial capacity density, various estimates include different components as part of the land area, such as whether the area between solar panels is considered in the total footprint, or setback and spacing requirements for wind turbines. Acknowledging that these spatial considerations are variable by, for instance, location and input assumptions, the low estimates in Table 3 reflect median values from published literature, specific to the United States where possible. Note, the high estimates are taken directly from Net-Zero America for wind and solar. Because geothermal was not considered in the Net-Zero America work, a literature estimate (from Fuchs et al., from 2021) was used for the high capacity density for geothermal.
Many acres of public land have the potential to host more than one technology given the resource availability. In this analysis, these overlaps were treated in two ways to explore the full range of sensitivities around site selection. When more than one choice was available, the “low density” scenario estimated the potential if the technology with lowest capacity density by land area is chosen every time, and the “high density” scenario estimated the potential if the technology with highest capacity density by land area is chosen every time. The allocation of all evaluated federal lands with variable resource potential is shown in Figure 1, characterizing which technologies are demonstrably modeled when multiple resource types are available. The results of the estimated hosting capacity associated with each scenario, as well as considered across the range of variable capacity densities by land area for each technology, are summarized by federal agency in Table 3. Land area estimates do not include the land required for other transmission and supporting infrastructure required to develop wind, solar, or geothermal projects.
In total, for the four federal agencies considered, 44% of all federal lands had resource potential for at least solar, wind, or geothermal. The remaining 54% of federal lands are characterized in the figure as “other federal lands (not suitable)”. Summarized in Table 3, the estimated upper bound of technical development potential varies by a factor of ten when a technology with a smaller spatial extent for the same capacity is chosen over a technology with a larger spatial extent. For example, when a low-density technology is given precedence where two or more resource types are available, there is 20 to 40 GW of hosting capacity potential on Bureau of Reclamation lands. When the high-density technology is given precedence where two or more resource types are available, that hosting capacity potential increases to 100 to 300 GW. However, the ranges shown illustrate that there is still a broad range in the estimates for potential hosting capacity when two capacity densities (low and high) are modeled for each technology (shown in Table 2). This analysis shows that the choice of energy technology is a larger factor in determining the total estimated capacity generation than the range in capacity density assumptions for a given technology.
| Federal Agency | Low-density technology chosen when resource available | High-density technology chosen when resource available |
|---|---|---|
| Total Estimated Generation Capacity (GW) (range represents low to high capacity density assumptions for each technology) | Total Estimated Generation Capacity (GW) (range represents low to high capacity density assumptions for each technology) | |
| Bureau of Land Management | 2,100 – 3,500 | 13,800 – 23,300 |
| Bureau of Reclamation | 20 – 40 | 100 – 300 |
| Department of Defense | 230 – 240 | 1,300 – 1,500 |
| Forest Service | 1,200 – 1,300 | 6,800 – 7,600 |
| Total | 3,550 – 5,080 | 22,000 – 32,700 |
Our estimate of technical potential for clean energy deployment on federal lands, and specifically BLM lands, is several orders of magnitude larger than the current target.
When applying the low estimates for capacity density by land area for each technology type and choosing the least land area dense technology where technical potentials overlap, we calculate that there is an estimated 2,100 GW of potential energy generation from of wind, solar, and conventional geothermal on BLM lands. The total estimated technical potential for energy generation across the four agencies for this “low-low” scenario is just over 3,500 GW. To put that into context, as of February 2023, there was an estimated 1,300 GW of generation capacity installed across the entire United States. These findings suggest that appropriately selected federal lands, with the wealth of technical resource potential characterized above, could play a larger role in hosting critical clean energy infrastructure.
BLM is on-track to meet its current “25 GW by 2025” clean energy target and other agencies are making progress.
The BLM tracks its progress toward the 25GW goal and as of January 4th, 2024, reported 27 approved solar, and geothermal projects with a total estimated output of 4.8GW, with 11.2GW if generation transmission infrastructure to connect projects to the energy grid (gen-tie) projects are included in the tally. They also detail 35 additional proposed projects (26 solar, 3 wind, and 6 geothermal) under review with a combined estimated potential output of 22 GW. These projects are either in National Environmental Policy Act (NEPA) review (~13.1GW of solar and geothermal) or preliminary review (8.6GW). If all these projects were approved, the agency would easily achieve its current goal. In addition, BLM also boasts the most diverse mix of clean energy generation technologies on their lands, including geothermal, solar, and wind.
Unlike BLM, the other three agencies represented in this analysis lack similar goals for clean energy permitting or deployment (see Figure 2). As reported by the Energy Information Agency (EIA)(form 860), the Department of Defense has several utility-scale wind, solar, and geothermal installations, while the U.S. Forest Service and the U.S. Bureau of Reclamation have very few (as of September 2022)., In November 2023, the Department of the Interior announced 15 new clean energy projects on federal lands across the western U.S. in service to reaching the 25 GW by 2025 clean energy goal.
President Biden’s Executive Order 14057 also requires that all federal agencies transition to “100% carbon pollution-free electricity on a net annual basis by 2030, including 50 percent 24/7 carbon pollution-free electricity.” To that end, the Department of Defense outlined its intent to host on-site clean and innovative energy generation, including next generation geothermal and advanced geothermal, in its April 2023 Plan to Reduce Greenhouse Gas Emissions.
Given the large technical potential on federal lands, BLM and other federal agencies should set ambitious clean energy targets for 2035 and beyond.
The results of this CATF analysis have implications for the ambition of current targets, the potential for other federal agencies to set targets, and the opportunity for clean energy deployment in western states, which host the lion’s share of federal public land, including most lands managed by the BLM.
- BLM’s current goal of 25GW should be a first step towards even greater ambition for clean energy permitting. This analysis shows that there is considerable headroom for raising the BLM clean energy target. Doing so will help meet the United States’ climate and energy sector decarbonization objectives and achieve our Nationally Determined Contributions (NDCs) to the Paris Climate Agreement.
- To improve the speed and scale of appropriate deployment of clean energy on federal lands, undertaking additional analyses will be beneficial. At the same time, other federal agencies can learn from BLM’s leadership in establishing and making progress towards a target for permitting clean energy.
- The Department of the Interior – which includes BLM and USBR, as well as agencies that manage off-shore energy – recently provided an update on their continued effort to advance clean energy projects on federal lands. That effort should consider analyses like this one to help right-size goals for development across the federal agencies given the extensive clean energy development potential.
- BLM should finalize strong versions of the rules it proposed on conservation leases for compensatory mitigation, managing for landscape health, and solar and wind energy development that incorporate the revisions recommended by CATF in our comments (wind and solar rulemaking, and conservation leases rulemaking). In addition, BLM should finalize an ambitious updated Western Solar Plan that recognizes the significant potential for utility-scale solar projects on public lands. These rules, plans, and other management practices can improve permitting reviews, promote best practices for siting and design of clean energy projects on federal land to accelerate clean energy deployment.
What’s next?
CATF will expand on this analysis to explore the potential synergies and trade-offs of responsible clean energy development on appropriate federal lands. Our future analyses will help inform the technology mix, ambition, and location of clean energy deployment on these lands to serve the public good by enhancing energy security and constraining climate change.
For more information or questions, please contact Mikenna Montgomery ([email protected]) or Jessi Eidbo ([email protected]).
