How we calculate potential solar capacity across the UK
Raster resolution: ~50m x 50m pixels (resampled from solar load factor data)
Power density assumption: 50 MW/km²
The solar tradeoffs tool shows the maximum possible land where solar PV could be deployed, based on geotechnical and safety constraints. This results in the headline total capacity number for each region.
These constraints are always applied and form the baseline available land:
| Constraint | Rule |
|---|---|
| Solar load factor | Any pixel with solar load factor less than 10% excluded |
| Airports | Any pixel within 20m of an airport excluded |
| Roads | Any pixel within 20m of a road excluded |
| Railways | Any pixel within 20m of a railway excluded |
| Overhead power lines | Any pixel within 20m of an overhead power line excluded |
| Waterways | All waterways excluded |
| Forest | All forest excluded (no buffer) |
| Public green spaces | All public green spaces excluded |
Users can toggle these constraints on or off:
Users can select from several levels, where higher levels provide more protection:
Level 1: No restrictions
Level 2: No building on Grade 2 farmland
Level 3: No building on Grade 1 or Grade 2 farmland
Level 1: No protections
Level 2: National Parks protected
Level 3: National Parks and Areas of Outstanding Natural Beauty protected
Level 4: Green Belt also protected
Level 1: 100m setback from listed buildings
Level 2: 500m setback from listed buildings
Level 3: 1000m setback from listed buildings
Level 1: No buffer
Level 2: 200m buffer
A final constraint removes any parcel of land smaller than 10,000 m² (1 hectare). This ensures only viable development sites are counted.