Verify Installer Solar Claims: Savings, Specs and Warranties Before and After Installation
Decision details
Fits if: Buyers holding an installer quote or claim (monthly savings, ROI, payback) who want to verify it, and new owners verifying delivery.
Main drawback: This page tests claims; it does not certify any installer, and no seller-complaint register is handled here.
Compare: written savings formula; generation and self-use assumptions; full price including fees; panel/inverter models on nameplates = quote; separate written workmanship and equipment warranties; install-day records.
In this guide
Short answer: three checkpoints
Check an installer’s claims at three points: before signing (test the savings claim), on installation day (match delivered equipment to the contract), and after installation (identify responsibility for warranties and maintenance).
Gate 1: test the savings claim against a reference calculation
TNB itself publishes a worked example for a 5 kWp residential system: 800 kWh/month usage; investment RM3,000/kWp = RM15,000; generation estimated at kWp × 3.5 hours × 30 days = 525 kWh/month; 75% self-consumed; 131 kWh exported credited at RM0.2703/kWh; the bill falls from RM345.89 to RM107.08; savings RM238.81/month or RM2,865.72/year; payback ~5.2 years [source].
That is the full shape of a healthy claim — formula, assumptions, price, breakdown. Use it as a template:
| Row | What the installer must state | Recorded reference |
|---|---|---|
| Full price | Total works and applicable charges; for Peninsular Solar ATAP the application fee is RM7.50/kWac. Check whether it is already bundled to avoid counting it twice, and identify any approved rebate [source] | TNB example uses RM3,000/kWp [source] |
| Assumed generation | kWp × sun hours × days, not 'cut your bill by 90%' | 5 kWp → 525 kWh/month at 3.5 hours × 30 days [source] |
| Self-use vs export | The % split and the export credit rate used | 75% self-use; exports credited RM0.2703/kWh in TNB's example [source] |
| Savings & ROI | RM per month and payback on YOUR full price | 5 kWp illustration using a RM19,499 advertised-price median: 5.8 years only with an approved maximum RM3,000 rebate; 6.8 without. Uses TNB example savings and does not deduct recurring costs [source] |
| Maintenance | Annual cleaning/inspection/service estimate, who bears it | July 2026 provider estimates: cleaning RM150–RM300/visit; inspection RM200–RM400. Undated inverter-service page observed 30 September 2026: From RM200. Request the services and prices for your site [source] [source] [source] |
Month-end sales pressure (‘price goes up tomorrow’) is not a reason to skip this template. A claim that cannot be rewritten as a formula cannot be held to account later.
Gate 2: install day — delivered goods are the contract
Do not assume delivered panel count, model or wattage matches the proposal. Compare the equipment installed with the written quote and contract, then keep nameplate photos and commissioning documents.
Install-day checklist (or before final payment):
- Count the physical panels; compare with the quote’s count.
- Photograph nameplates of each panel type (model, wattage) and the inverter label (kWac, model).
- Match models against the contract’s equipment list — not against verbal descriptions.
- Visually check mounting and cable runs; keep the photos.
- Ask for commissioning documents and initial monitoring readings.
If there is a difference, send a dated written record with photos and ask the provider to explain how delivery complies with the contract before the next payment due under the agreed schedule. Check the signed documents for your options; this guide does not determine contractual remedies.
Gate 3: warranties and maintenance after installation
Two warranty classes must not be blended:
- Equipment warranty (manufacturer). Panel models have model-specific power warranties; one example is the Jinko Tiger Neo JKMxxxN-72HL4-(V)-L, April 2024 revision, listing a warranty degradation ceiling of 1.00% in the first year, then 0.40% per year for 30 years [source]. Check the exact model and revision offered. For a home battery, rely on the warranty document for the exact residential model; this page does not establish a home-battery cycle-life figure.
- Workmanship warranty (installer). One published Solana Tec policy starts at commissioning and covers specified mounting, roof attachments, roof leaks directly caused by the PV installation and installer wiring, subject to stated exclusions [source]. It describes that provider’s policy only, not a market standard or the outcome of an individual claim.
If your quote limits workmanship cover to leaks or a particular period, ask for the start date, work scope, exclusions, labour and claims contact in writing. The Solana policy above is one provider example only. The TNB Solar ATAP contract runs up to 10 years from commissioning; after that the installation is for self-consumption [source]. If a savings projection extends beyond that term, ask what export assumptions it uses afterward.
An equipment or workmanship warranty does not, by itself, guarantee bill savings or lost revenue. If an offer separately promises performance or savings, ask the contract to define the metric, baseline, measurement period, assumptions and exclusions, responsible party, and remedy if the terms are missed. A projection without a written remedy remains a projection.
When a dispute happens
A practical sequence: (1) send the provider a dated written record with photos and documents, stating the question or resolution requested; (2) if unresolved, check the party or process named in the contract; (3) for consumer issues, check the relevant complaint channel. Gate 1 and 2 records help show what was offered and installed; they do not determine your rights or the outcome of a dispute.
Frequently asked questions
The installer says ROI in 5 years. Believable?
A number in years is payback, not an ROI rate. Request the full price before and after any approved rebate, roof-specific generation, self-use, exports, account tariff and recurring costs. Divide net purchase cost by net annual savings. TNB and advertised-price illustrations do not establish a fair benchmark for every house; test the provider’s own inputs.
What should I check on installation day?
Count the panels and photograph the nameplates (model, wattage, serial) and inverter label; compare them with the quote and contract equipment list. If anything differs, document it and ask the provider in writing how the delivered equipment matches the agreed documents.
How do I know a warranty is real?
Ask for two separate written documents: the manufacturer's equipment warranty (for example, one Jinko Tiger Neo model/revision lists a warranty degradation ceiling of 1.00% in the first year, then 0.40% per year for 30 years [source]) and the installer workmanship warranty. One published Solana Tec policy starts at commissioning and covers specified mounting, directly caused PV-installation roof leaks and installer wiring, subject to its stated exclusions [source]. If your offer limits cover to leaks or a short period, ask in writing for the start date, scope, exclusions, labour and claims contact. One provider's policy does not establish a market norm.
Are there hidden costs after installation?
Ask which services your site needs, how often, what the package includes and who pays. July 2026 provider estimates list cleaning at RM150–RM300/visit and inspection at RM200–RM400. An undated inverter-service page observed on 30 September 2026 says From RM200. These are provider examples, not mandatory costs for every home or paid invoices. [source] [source] [source]
Does a panel or workmanship warranty guarantee savings or revenue?
Not by itself. If an installer offers a separate performance or savings commitment, ask for the metric, baseline, measurement period, exclusions, responsible party and written remedy. Keep that term distinct from equipment and workmanship warranties.