Checklist: solar
Put every solar quote on the same page before you choose
The easiest way to buy badly is to compare only the total price. Use the same fifteen checks on every installer so differences become obvious.
Last reviewed: October 2026
The fifteen checks
- 01Total array size in kWp.
- 02Panel make, model and quantity.
- 03Inverter make, model and output rating.
- 04Annual generation estimate in kWh.
- 05Roof orientation and shading assumptions.
- 06Self-consumption percentage used in the savings forecast.
- 07Export tariff assumption, if one is used.
- 08Scaffolding and access included or excluded.
- 09Roof works and mounting system.
- 10Electrical work and any consumer-unit changes.
- 11DNO application or notification responsibility.
- 12MCS certification and handover paperwork.
- 13Panel, inverter and workmanship warranties.
- 14Battery price shown separately, if storage is included.
- 15Total installed price and deposit/cancellation terms.
Compare up to three quotes side by side
Type the figures from each proposal into the same rows. A blank cell is a question to send back to the installer, not a detail to guess.
Then put each proposal through the solar calculator using the same import price, export price and self-consumption assumption.
| Quote detail | Quote 1 | Quote 2 | Quote 3 |
|---|---|---|---|
| Installer and proposal date | |||
| Total installed price | |||
| Array size (kWp) | |||
| Panel make, model and quantity | |||
| Inverter make and model | |||
| Annual generation estimate (kWh) | |||
| Self-consumption assumption | |||
| Scaffolding and roof work included | |||
| Electrical work included | |||
| DNO and MCS paperwork | |||
| Product and workmanship warranties | |||
| Deposit and cancellation terms |
Red flags
- A payback figure with no visible generation or self-consumption assumptions.
- A bundled battery price that cannot be separated from the solar price.
- No roof layout before taking a deposit.
- Scaffolding described as 'subject to survey' with no allowance in the price.
- A warranty described only by its length, with no explanation of who honours it.
- Pressure to sign before you have compared another quote.