// Overpass QL query for the OpenStreetMap solar-site extraction (Section 2.5; File S1).
// It selects closed ways and multipolygon relations within Bulgaria tagged power=plant and plant:source=solar.
// The date setting returns OpenStreetMap as it was at 20:30 UTC on 1 September 2026, so the result does not
// depend on later edits. At this date the query returns 696 ways and 8 relations, which correspond one-to-one
// to the polygons PV001-PV696 (ways) and PV697-PV704 (relations) of File S1. None of the relation members is
// itself tagged as a plant, so no site is counted twice.
// Run at https://overpass-turbo.eu (paste the query, press Run, then Export > GeoJSON, which assembles the
// relations into multipolygons) or send it to https://overpass-api.de/api/interpreter.
// After download, geometries were repaired where necessary and overlapping polygons were dissolved so that each
// location is counted once (Section 2.5).
// Data (c) OpenStreetMap contributors, available under the Open Database License (ODbL 1.0).

[out:json][timeout:600][date:"2026-09-01T20:30:00Z"];
area["ISO3166-1"="BG"][admin_level=2]->.bg;
(
  way["power"="plant"]["plant:source"="solar"](area.bg);
  relation["power"="plant"]["plant:source"="solar"](area.bg);
);
out geom;
