Quick Answer
A plug and two panels do not make a safe, compliant kit. Use this checklist to compare the technical file, mounting, operating mode and after-sales support before paying.
Ask for a complete delivered and installed price
Compare identical scopes: panel and inverter models, suitable mounting, export control where required, cables and protection, electrical assessment, fitting, access equipment, administration, delivery and tax. An inexpensive box may omit the parts that make it usable at your property.
Illustrative budget comparison, not market prices: a EUR 450 kit plus EUR 180 mounting and EUR 270 assessment/fitting totals EUR 900. A EUR 700 package including suitable mounting plus EUR 150 fitting totals EUR 850. These invented figures show why the headline kit price cannot decide the purchase; both options still need a suitability check and any missing costs added.
Send the seller this request before paying
Please provide the exact panel and inverter models, nominal AC output, declaration of conformity, installation instructions, intended export mode, required protection, mounting specification for my railing, and an itemised price including tax. Please confirm who checks electrical suitability, who handles required paperwork, and the return arrangements if the proposed installation is unsuitable.
Attach measurements and photographs through a private channel. Do not send an unredacted electricity bill to an unknown marketplace seller. An answer saying only “CE approved” or “legal below 800 W” leaves the important questions unresolved.
Accept, clarify or stop
- Ready for professional assessment: exact models, matching documents, a defined connection mode and a mounting proposal for the actual structure.
- Clarify before paying: missing prices, uncertain warranty contact, an unexplained app subscription or no responsibility for commissioning.
- Stop: improvised mounting, damaged structure, no electrical assessment, or pressure to ignore property and electrical requirements.
Start with the proposed operating mode
Ask whether the kit is designed for zero export or export. That choice controls required equipment and procedures. A seller should identify nominal inverter output in VA, maximum panel input, connection method and the documents supplied for Spain.
Microinverter evidence
- Manufacturer and exact model, not only a marketplace brand.
- EU declaration of conformity and applicable grid-interface evidence.
- Anti-islanding behavior and reconnection settings.
- Maximum AC output, leakage-current data and protection requirements.
- Outdoor ingress rating and operating-temperature range.
- Spanish warranty contact and firmware-support policy.
Panel and mounting checks
- Exact panel dimensions, weight and electrical limits.
- Mounting approved for that panel and balcony construction.
- Documented wind resistance and corrosion-compatible hardware.
- Connector compatibility; avoid mixed connector brands unless explicitly approved.
- Cable length that reaches safely without permanent extension leads.
Commercial warning signs
Walk away when the seller says 800 W means “no rules,” refuses to provide documents before purchase, advertises guaranteed annual savings, suggests attaching panels with generic ties, or cannot explain export control. A CE logo alone is not a full technical file.
Documents to retain
Keep the invoice, serial numbers, data sheets, declarations, installation instructions, mounting calculations, installer findings, community or landlord consent, photographs and commissioning records. These support warranty, insurance and future property questions.