Guide
12 points to check when comparing solar panel quotes
You have several quotes and the numbers differ. The lowest total is not always the best offer; to see where the gap comes from, read every quote against the same points. This guide gives you a 12-point checklist for lining up bids.
Short answer
To compare quotes for a solar energy system, first align the scope, then check unit cost in cost per kWp. Next go through panel and inverter brand and model, product and performance warranties, the workmanship warranty, mounting and electrical details, who handles permits and connection, the yield assumptions and the maintenance scope. Every item left out can come back later as an extra cost.
This guide was prepared by the Ufkon editorial team and reviewed on 19 Oct 2026. It is for information only and does not replace legal, financial or technical advice.
Before comparing: align the scope
The steps for collecting quotes and reaching firms are in the solar panel quote guide. This page covers the next step: reading the quotes you have on the same scale. Start by writing what each quote covers in one table. If an item is included in one quote but excluded in another, the totals cannot be compared directly.
The 12-point comparison list
| # | Point | What to ask | Warning sign |
|---|---|---|---|
| 1 | Installed capacity | Are panel power (kWp) and inverter power (kW) listed separately? | A single "system size" figure only |
| 2 | Cost per kWp and total | Are the total excluding VAT and cost per kWp based on the same scope? | Exclusions not listed |
| 3 | Panels | Brand, model, quantity, unit power (Wp) and datasheet? | Vague terms such as "grade A panels" |
| 4 | Inverter | Brand, model, quantity, power and type (string, micro, hybrid)? | Power only, no model |
| 5 | Product warranties | How many years for panels and inverter, and who honours them? | Unclear warrantor |
| 6 | Performance warranty | Term and annual degradation curve stated? | Only "long life" |
| 7 | Workmanship warranty | How many years for mounting and roof sealing? | No written workmanship warranty |
| 8 | Mounting and structure | Materials, roof fixing method, scaffolding and safety included? | Roof suitability assumed without a survey |
| 9 | Electrical equipment | Cable sizes, panel board, protection, earthing and surge protection included? | Listed only as "necessary materials" |
| 10 | Permits and connection | Who handles design, application and connection, and is it included? | Not mentioned at all |
| 11 | Yield estimate | Which assumptions (location, pitch, losses) give the annual yield? | A single figure without assumptions |
| 12 | Monitoring, maintenance, service | Are monitoring, periodic maintenance, cleaning and response time defined? | After-sales support left vague |
Reading warranties correctly
A solar panel quote usually carries three different warranties that should not be confused. For each warranty, ask for the term, the scope and who honours it: the maker, the local distributor or the installer. Ask for a sample warranty document before signing.
Product warranty
Covers manufacturing defects in panels and inverter. Terms vary by equipment and should be listed separately for each.
Performance warranty
Commits that the panel keeps a set power level over the years. Read the term and the annual degradation curve on the datasheet and warranty document.
Workmanship warranty
The installer's promise on its own work; roof sealing and sound connections usually fall here. If it is not in writing, assume there is none.
Why cost per kWp alone is not enough
Cost per kWp is the total excluding VAT divided by installed capacity, and it puts bids of different sizes on one scale. Yet the same figure can hide very different scopes: one may include design and connection work and another not; one may offer a longer warranty or broader maintenance. Align the 12 points first, then look at unit cost.
For bids in foreign currency, add the exchange rate assumption, payment plan and price validity to the same table. See solar panel cost for the items that drive cost.
Understanding technical differences
Firms may propose different panels or inverters. To see how this affects yield, read the solar panel types and inverter choice guides. For large projects such as factories, the structural check, connection point and schedule belong in the comparison too. Make sure every bid serves your renewable energy goal to the same degree.
Ufkon names no winner and shows no "recommended bid". When you create a project request, firms can fill in the same bill of quantities (BOQ) template if you wish, and bids appear side by side in cost per kWp; the decision and the contract are yours. See how it works.
Final check before signing
Once you pick a bid, the contract is where everything discussed is put in writing. Before signing, make sure it clearly states:
- The brand and model of the quoted equipment; any change only to an equal or better item and with your approval
- The payment plan, the exchange rate clause and the work stage each payment is tied to
- The schedule, what happens on delay and the acceptance criteria
- Documents delivered at handover: design, test results, warranty documents, monitoring access
- Maintenance, fault response time and the contact channel
Frequently asked questions
Should I pick the cheapest quote?
If scopes are equal, unit cost is an important measure. But missing items, short warranties or vague equipment can hide behind a low price. Align the 12 points first, then look at the price.
What if the quote does not name the panel brand?
Ask for brand, model and datasheet. A quote without defined equipment cannot be compared and carries the risk of different equipment being installed.
Why do yield estimates differ between firms?
Irradiation data, pitch and orientation assumptions, shade and system losses can differ. Ask each firm for its assumptions in writing; the capacity calculator gives an independent first idea.
Who honours the warranty?
The maker usually gives the product and performance warranties and the installer the workmanship warranty. Agree before signing where and how a local warranty claim is made.
Does Ufkon evaluate the quotes?
No. Ufkon does not score bids or pick a winner; if you wish, you see the bids side by side in the same template. Ufkon never installs and takes no commission on your deal.
What does a large price gap between quotes show?
Usually a difference in scope, equipment or warranty. One bid may include design and connection work, scaffolding or maintenance while another excludes them. If a bid does not explain the gap, ask for an itemised breakdown.
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