Value chain · CLM-0317
In plain terms
Two studies of how much land US ground-mounted solar farms need, the second drawing most of its measurements from the first, indicate once converted to the same units that the receiving antenna of a space solar power design already in the register would need roughly a quarter to a fifth as much ground per unit of electricity delivered.
The claim as recorded
Converting NREL's average total land-use requirement for US utility-scale PV and Lovering et al.'s median land-use intensity for US ground-mounted PV to the same watts-per-square-metre basis as the SBSP figure at CALC-001 (29.2 W/m2, from a UK reference design) gives approximately 7.83 W/m2 from NREL's 3.6 acres/GWh/yr and approximately 5.70 W/m2 from Lovering et al.'s 2,000 hectares/TWh/yr, a 3.7x to 5.1x land-efficiency advantage for the rectenna footprint of the SBSP design already in the register. The two terrestrial figures are not independent: about two thirds of Lovering et al.'s named PV area measurements come from NREL's study.
Scope and limits
CALC-001's SBSP figure counts only the rectenna footprint; Lovering's table reports "total direct and indirect land use", but for ground-mounted PV its figure is direct area only ("the area of panels or heliostats, roads established during development, and all ancillary facilities", p.6; indirect area is "the land needed to source power plant fuel", "if applicable", p.7), and the paper states that its calculations "do not include upstream land impacts from manufacturing of materials" (p.8). SBSP's own indirect land footprint (manufacturing sites, launch infrastructure) is not counted here and has not been assessed. Both terrestrial figures describe existing US plants (Lovering: plants over 20 MW in 18 US states, p.5). This claim may be used to support a land-use advantage for the rectenna footprint specifically; it may NOT be used to claim a full lifecycle land-use advantage until SBSP's indirect land use is assessed. The programme's own 1980 land-use comparison (CLM-1052, DOE/ER-0054) spans 0.4x to 5.1x for the rectenna against terrestrial PV depending on whether the 2 km microwave-safety buffer is inside the SPS boundary and whether cell area or plant area is counted for PV; this record's 3.7-5.1x is the rectenna-only, plant-area corner of that range (back-linked 2026-09-18).
What it assumes
This calculation treats NREL's average (whose annual generation is simulated, per its p.17) and Lovering's median (from EIA-reported generation at existing US plants) land-use figures as directly comparable with CALC-001's design-basis SBSP figure, which is itself a projected reference-design number, not a measured one.
Where it comes from
This is the project's own working, shown in full:
Working shown: NREL (SRC-188, p.17): "Average total land-use requirements are 3.6 acres/GWh/yr for PV and 3.5 acres/GWh/yr for CSP." 3.6 acres = 14,569 m2; 1 GWh/yr = 1e9 Wh/yr; average power = 1e9 / 8,766 h = 114,077 W; 114,077 / 14,569 = 7.83 W/m2; 29.2 / 7.83 = 3.7. (NREL's all-solar average, 3.5 acres/GWh/yr at Table ES-1, p.v, includes CSP and would give 8.05 W/m2.) Lovering et al. (SRC-189, Table 1, p.8): ground-mounted PV median total land-use intensity 2,000 ha/TWh/yr. 2,000 ha = 2e7 m2; 1 TWh/yr = 1e12 Wh/yr; average power = 1e12 / 8,766 h = 1.141e8 W; 1.141e8 / 2e7 = 5.70 W/m2. Existing register figure: CALC-001, 29.2 W/m2 (2 GW delivered over a 68.4 km2 rectenna, SRC-023).
Basis: mixed 2013 and 2022 study years; SBSP figure from a 2021 UK reference design
Related records
- Answers question
- QST-007 not published in this release
Cite this
energyaperture.com/c/clm-0317
CLM-0317, Energy Aperture, as of 2026-09.
Connected records
Other published records linked to this one. A list, not a judgement.