Solar quote assumptions checklist
This checklist is for comparing assumptions behind solar quotes. It is useful before you speak to an installer and again before you sign.
Roof and system
Direction, shade, panel count and total kWp.
Money and tariff
Installed cost, import price, export rate and battery cost.
Real life
Daytime use, future electricity demand and how confident you are in each estimate.
Copy this into your quote notes
For each quote, write down the assumptions in the same order. Missing answers are not automatically bad, but they are questions to ask.
- System size
- Annual generation
- Self-use percentage
- Export price
- Import price
- Battery size
- Degradation
- Maintenance or inverter replacement allowance
Use the checklist to slow the decision down
A good solar decision should feel clearer after questions, not more rushed.
Useful sources: Ofgem SEG, GOV.UK VAT relief.
Compare three quotes on one page
Use one column for each written quote. Copy the numbers exactly as the installer gives them. A blank box is a question to ask, not a reason to guess.
Your entries stay in this browser page. Here4Solar does not receive or save them. Print the completed sheet or use your browser’s “Save as PDF” option if you want to keep a copy.
Start with like-for-like systems
Check whether each company has priced the same system size and the same work. A quote with a battery, roof repairs or a fuse-box change cannot be compared fairly with a panel-only price until those extras are separated.
Find the assumption changing the payback
Large differences often come from annual generation, daytime self-use, electricity prices or export rates. Ask the installer to show where each number came from and whether it can change.
Keep evidence with the final choice
Save the quote, system design, monthly generation estimate, product details, warranties and any later survey changes. If a number changes before you sign, update this sheet and compare again.
Final check: a faster payback is not proof of a better design. Re-run all three quotes with the same electricity prices and export rate in the payback calculator.
Optional next step
Checklist ready? Put it to work on a quote.
Take the assumptions from this checklist into a real quote and ask for the details behind the numbers.
- No pressure from Here4Solar
- Personalised home quote
- Check if solar could work
Compare at least three written quotes before choosing an installer.