Practitioners’ perceptions of biodiversity-relevant criteria for solar suitability analyses in the United States

Global acceleration of large-scale (i.e., >1-megawatt capacity) solar energy deployment poses competition for land, including vital biodiversity conservation areas. Solar suitability analyses (SSAs) help preemptively identify low-conflict zones for solar development. However, limited studies show which biodiversity-relevant criteria (BRCs) are essential for SSAs and the extent to which data underpinning them is available. Supporting parallel biodiversity and clean energy goals, we solicited a panel of United States-based practitioners with expertise in biodiversity and renewable energy development to identify BRCs for SSAs. Practitioners participated in a Delphi-style focus group, distinguishing ‘core’ criteria (essential for all SSAs) and ‘peripheral’ criteria (data or scale-limited). The panel identified 16 core and 13 peripheral BRCs, providing examples of national geospatial databases supporting the former. Assessing a hypothesized relationship between regulatory compliance and BRCs use, we highlighted linkages between federal legislation and practitioner-defined core BRCs. Further, we examined 13 United States-based SSAs to gauge how contemporary research at the time of our study applied these BRCs. Our results show that practitioners primarily identified core BRCs relating to legal compliance, with consistent and open-access data available for 14 of the 16 criteria across 10 databases. However, our assessment of US-based SSAs revealed that only 10 included practitioner-agreed core BRCs (count max: n = 14, min: n = 0), while database usage varied. We provide BRCs data sources identified by practitioners and study authors in an online repository. Our findings highlight the need for updated data on BRCs at granular spatial scales to address underrepresentation in forthcoming SSAs.