Commercial solar quote checklist
What to check across every proposal before comparing headline prices.
System
- System size (kWp), module count, make and model
- Inverter make, model and capacity
- Mounting system and whether optimisers are used
- Battery capacity, if included
Price
- Total price ex-VAT, and what it does and doesn't include
- £/kWp — and what that figure includes relative to other quotes
- Battery cost and any additional works, itemised separately
Generation
- Claimed annual generation and specific yield (kWh/kWp)
- Degradation, shading, orientation and tilt assumptions
- Whether an independent yield estimate is possible for your site
Savings assumptions
- Self-consumption and export assumptions
- Which electricity rate is used to value savings, and whether it includes standing/network charges that don't scale with consumption
- Assumed annual electricity price escalation
Scope
- G99 application and DNO fees — included or not?
- Structural survey, roof repairs, fragile-roof or asbestos considerations
- Scaffolding, access, crane or cherry-picker costs
- Electrical works, LV upgrade, switchgear
- Monitoring, fire safety requirements, commissioning, export meter
Warranties
- Module product and performance warranty length
- Inverter and battery warranty length
- Workmanship warranty, and whether it's insurance-backed
Payment terms
- Deposit percentage and staged payment schedule
- What triggers final payment
- Retention, if any
This is the same checklist our reviewers work through — see how we review. Rather do it once, properly? Upload your proposals and we'll work through this for you.