How much does commercial solar cost in 2026?
Commercial solar costs vary with system size, roof condition, electrical infrastructure and grid requirements. This guide explains the figures that shape a realistic budget and why the lowest headline price is not always the best long-term value.
Key takeaway
A commercial solar quote should be judged on lifetime energy value, not price per panel. Design quality, realistic generation modelling and aftercare materially affect the return.
Typical commercial solar costs
As an initial planning guide, many UK commercial rooftop projects sit between roughly £700 and £1,200 per installed kWp before VAT. Larger, straightforward roofs can achieve economies of scale, while smaller or technically complex sites often cost more per kWp.
| Indicative size | Typical use | Illustrative budget |
|---|---|---|
| 50 kWp | Small warehouse, office or farm building | £45,000–£65,000 |
| 100 kWp | Medium commercial premises | £75,000–£110,000 |
| 250 kWp | Large warehouse or factory | £175,000–£260,000 |
| 500 kWp | High-consumption industrial site | £325,000–£500,000 |
These are broad 2026 planning ranges, not quotations. A site survey and half-hourly electricity data are needed for an accurate proposal.
What affects the price?
Two systems with the same capacity can have different costs because the work around the panels is different. A competent assessment considers the complete installation.
- Roof type, access, height and structural loading
- Panel, inverter and mounting-system specification
- Scaffolding, lifting equipment and site logistics
- Switchgear, cabling and any electrical upgrades
- Distribution Network Operator application requirements
- Monitoring, warranties and ongoing maintenance
Payback and lifetime savings
The strongest returns usually come when a business uses a high proportion of the electricity as it is generated. Every solar unit used on site replaces electricity bought from the grid; exported energy normally earns less.
Many suitable projects model a simple payback in the region of four to eight years, but this changes with electricity price, finance cost, daytime demand and system performance. Panels commonly continue generating for 25 years or more, so the post-payback period can create substantial value.
Ask for assumptions to be shown clearly: annual generation, self-consumption, degradation, electricity inflation and export rate.
What should a commercial solar quote include?
A robust proposal should make it easy to compare scope as well as price. Look for an itemised system design, generation estimate, savings model, warranties, installation programme and confirmation of what is excluded.
- A layout based on measured roof and site constraints
- Expected annual generation and self-consumption
- Equipment makes, models and warranty periods
- Grid application and planning responsibilities
- Health and safety, access and business-continuity planning
- Monitoring, handover and aftercare
Written by Horizon Commercial Solar. Reviewed by our commercial solar team and updated 23 September 2026. Figures are illustrative and depend on site conditions, tariffs and project scope.
