Global land and solar energy relationships for sustainability

Global energy transitions with high growth in solar power in meeting net zero goals by 2050 must consider solar energy-land interactions and economics to align sustainability goals. We quantify a capacity-weighted average value of land-use efficiency (LUE) as 56.8 (36.9-62.1, 25th-75th percentile) W/m2, and lifetime land transformation (LT) as 408.6 (311.7-587.0) m2/GWh for all large, ground-mounted photovoltaic plants globally. Asia-Pacific had a 14.7% higher LUE (and a 21.0% lower LT) compared to other regions. These results inform levelized-cost of energy and sustainability comparisons of rooftop (land-sparing) versus large, ground-mounted (land-intensive) photovoltaic build-outs by country and region. These findings suggest that the substitution of land-intensive for land-sparing photovoltaic buildouts is most expensive in India (51.2 $/MWh) and least expensive in the United States (34.2 $/MWh). Results point to the need to determine economic implications of global land-sparing opportunities and enact policies to enhance techno-ecological synergies.