Proximity analysis of low-carbon energy infrastructure: Implications for environmental justice in the United States

The global transition to low-carbon energy requires the rapid deployment of solar, wind, transmission, and nuclear infrastructure. Equity concerns around where these assets are sited remain unevenly assessed across technologies. This study conducts a national, tract-level proximity analysis of the contiguous United States to test whether communities identified as vulnerable by EPA EJScreen are located closer to, or farther from, major operational low-carbon infrastructure. The analysis integrates EIA Form-860 (year-end 2022) locations for utility-scale solar (>1 MW), onshore wind (>1 MW), and nuclear plants; HIFLD transmission lines (≥230 kV, ∼2022–2023); and Census TIGER 2023 tract boundaries, harmonized in EPSG:5070. For 84,415 tracts, I compute nearest-feature distances and compare vulnerable (≥75th national percentile for low-income or people-of-color) versus non-vulnerable tracts using Mann-Whitney tests, Welch's t-tests, and effect sizes (Cliff's δ). Vulnerable tracts are closer to solar (median 12.56 km vs 16.81 km; Δ = −4.25 km) and transmission (0.96 km vs 1.33 km; Δ = −0.37 km), but farther from wind (102.95 km vs 90.38 km; Δ = +12.57 km) and nuclear (151.41 km vs 135.79 km; Δ = +15.62 km) (all p < 0.0001). Differences in magnitude vary by technology, underscoring that statistical significance does not always imply substantive effects. Proximity is only one facet of energy justice; it does not capture exposure intensity, benefits, or procedural fairness. Nonetheless, the comparative, replicable approach provides technology-specific signals for equity-focused siting: prioritize equity screens for solar and transmission corridors and ensure benefit-sharing and lifecycle risk governance for wind and nuclear. The study outlines sensitivity tests and a reproducibility appendix to support longitudinal tracking and policy evaluation.