Clarify who carries the product warranty and the performance warranty
Distinguish product warranty from performance warranty: what you are really signing
In the quote and in the technical file, clearly separate the product warranty (material and manufacturing defects, connectors, frame, junction box) from the performance warranty (power degradation over time, often linear). It is not the same proof required, nor the same processing time. Lock down the exact module reference and warranty documentation at the time of order; this is your contractual document.
Identify the warranty holder by channel (specialist wholesaler vs manufacturer) and the stated durations
With a specialist wholesaler, you are buying a service in addition to the box. With a direct purchase, you may sometimes gain on price, but you often manage the manufacturer relationship yourself. A serious solar panel distributor formalises who decides on the replacement and who covers transport.
| Channel | Operational warranty holder | Product warranty (years) | Performance warranty (years) |
|---|---|---|---|
| Specialist wholesaler | Wholesaler + manufacturer (depending on contract) | 12 to 25 | 25 to 30 |
| Direct manufacturer purchase | Manufacturer | 12 to 25 | 25 to 30 |
Anticipate the risk of a supplier disappearing: the real cost of after-sales service
If your contact disappears, the warranty becomes theoretical. Include after-sales service in your margin. Administrative time, RMA, downtime, electrical retesting, and return logistics. Require an EU entry point or an authorised representative, and a clause covering costs. This is often where the real profitability is decided.
Secure your claims when the manufacturer is outside the European Union
Understand the claims process: evidence required, deadlines, logistics, and exchanges
Set out a claims process from the order stage. Build a complete photo file. Serial numbers, labels, pallets, defects, flash test or I-V curve, delivery note, and handover report. Specify reporting deadlines, DOA sorting, and return logistics.
Check for a representative or stock in the EU: direct impact on resolution
When the manufacturer is outside the EU, look for an economic operator established in the Union and buffer stock. Without a local relay, the application of Regulation (EU) 2019/1020 and after-sales processing take longer. A solar panel distributor with EU stock limits downtime and secures exchanges.
Define responsibilities contractually: credit notes, returns, replacement, and transport
In your general terms and conditions or framework agreement, state who covers the credit note, replacement, outbound and return transport, packaging, Incoterms, and insurance. Require a written RMA, a sorting procedure, and an advance replacement option when the batch is critical. Provide for the case where the supplier ceases trading. For the administrative side, also see the credit note.
Ensure series availability and lead times compatible with your projects
Avoid shortages: tracking current series and managing end-of-reference situations
Lock down the reference at the estimating stage. Request written notice of end of series, a discontinuation date, and an equivalent replacement solution. Reserve an identified batch and keep traceability (reference, batch number, serial number).
Compare real lead times: wholesaler stock, factory order, transit, and customs clearance
Do not compare a stated lead time. Compare a delivered lead time, with proof of stock at your solar panel distributor. For factory orders, define the Incoterm, transit, customs clearance, and who bears the risk in the event of a hold-up.
Manage reference changes during the project: redo the design and the declaration
Any module change requires redesigning the layout, strings, inverter compatibility, and datasheets. If the declared power or equipment changes, update the connection request and file documents. Set an internal rule. No swap without approval.
Calculate the discount and the real margin beyond the watt-peak price
Identify the volume thresholds that trigger a discount and the related conditions
For a module purchase, discounts follow logistics thresholds. Check the discount conditions before comparing. Fixed reference, Incoterm, lead time, deposit, dispute handling. An advertised discount can disappear if the series changes during the job.
| Threshold | Logistics threshold (pallets) | Common trade-off |
|---|---|---|
| Pallet | 1 | Faster payment, collection from depot |
| Full truckload | 33 | Strict delivery window, unloading at your cost |
| 40-foot container | 24 | Transport risk, customs, documentation to provide |
Factor storage, breakage, insurance, and cash tied up into your full cost
The price per Wp does not reflect your full cost. Budget for storage, breakage, transport insurance, receipt inspection, cash tied up, and time spent on claims. Bring everything back to kWp, then decide. To frame the immobilisation side, you can rely on payment terms.
| Item | Unit | Estimating basis |
|---|---|---|
| Storage | €/pallet/week | Floor space, handling, security |
| Breakage, scrap | % | Provisions based on history |
| Transport insurance | % of value | Depending on Incoterm and coverage |
| Cash tied up | €/€-month | Deposit, installation delay, collection |
Choose your model: just-in-time purchases from a solar panel distributor or factory batches
With just-in-time purchasing through a solar panel distributor, you buy availability and an after-sales contact. With factory batches, the discount may improve, but you carry the after-sales risk if the supplier disappears or if the manufacturer is outside the European Union. Change a reference, and you must redo the design and the declaration.
Gather the traceability required for grant files and site handover
Build a solid file: invoices, delivery notes, serial numbers, and datasheets
For a complete file, ask your solar panel distributor for dated, named documents. Ensure consistency between quote, invoice, and handover file.
- Detailed invoice, references, quantities, unit power, batch number where available.
- Delivery notes, pallet labels, proof of receipt.
- List of serial numbers, photos of nameplates before installation.
- Technical datasheets and manufacturer conformity declarations.
Secure module compliance: exact references, markings, and document consistency
Keep a single module reference for the whole project. If the reference changes, redo the design, the grid declaration, and update the handover file.
- Check the CE marking, exact model, and consistency between labels and the datasheet.
- Verify that the documents match the invoice and the signed certificates.
Organise your internal traceability: from pallet arrival to installation, without losing information
Set up a simple document chain. At depot intake, record batch and serial numbers. On site, map the series by zone and by inverter. At handover, archive the handover file and acceptance report with photos, as detailed in the handover report and quality control points.
