Financial comparison engineCapex vs PPA vs Lease25-year economic horizon
Will this site pay back? Compare your build options.
The site clears the Grid Check. The capex is doable. But which financing structure actually wins? Compare self-build, on-site PPA, sleeved corporate PPA, and rent-a-roof lease — for any site, any capacity, with the real UK 2026 rates.
Live calculation engine. Uses real UK 2026 PPA rate ranges, capex benchmarks (£/kW), commercial import tariffs, and SEG export rates. Production v2 will pull live PPA quotes from market intelligence sources (Cornwall Insight, Aurora, Modo Energy) and site-specific Half Hourly load profiles.
Best 25-year NPV for your scenario
Self-Build delivers £—k NPV — but requires £—k upfront capex.
If capex is constrained, the next-best option is an On-Site PPA at —p/kWh delivering £—k NPV with zero upfront.
Four financing options compared
500 kW commercial solar in UK Power Networks · East England · 950 kWh/kW/yr yield assumption
UK 2026 commercial solar rate landscape
Where each option sits on the £/kWh spectrum (low → high; lower is better for the site owner)
Self-Build LCOE 5–8 p/kWh
SEG Export 5–7 p
Sleeved PPA 7–10 p/kWh
On-Site PPA 9–13 p/kWh
Grid Import 25–32 p/kWh
Sources: Cornwall Insight UK Solar PPA Index Q1 2026 · Ofgem default tariff cap commercial bands · SEG license rates 2026 · BEIS LCOE estimates for commercial rooftop solar