Interactive tool
Solar Carport ROI Calculator
Enter your parking bays and annual electricity spend. Get an instant indicative system size, capex range, annual saving, payback period and 25-year net benefit.
UK midlands 850; South 950; North 800
Your Indicative Numbers
How the Calculator Works
The tool uses the same formulas we apply in feasibility studies:
- System size: 1.5 kWp per parking bay (single-deck flat carport, bifacial Tier-1 panels)
- Annual generation: kWp × yield (kWh/kWp/yr) × 0.8 performance ratio
- Self-consumption rate: 78% — typical commercial daytime load matching
- Export rate: 7p/kWh under Smart Export Guarantee (SEG) — Octopus, EDF, OVO leaders
- AIA benefit: 100% first-year capital allowance up to £1m capex; effective tax saving = capex × tax rate
- EV revenue assumption: 4 charging sessions/socket/week × £250 annual margin per session at 35% capture
The actual quote will differ — better yield in southern UK, higher unit rates currently, and project-specific structural costs. Use this for first-pass sizing only; we provide a fixed-price quote within 48 working hours of receiving your site details.