A PV system may involve several different warranties and protections. A module maker’s commercial product warranty may cover defects; a separate commercial power guarantee may state the output level a panel is expected to retain under a defined method and schedule. Neither guarantees the annual generation of the whole system, savings on a bill or the performance of every component.

Identify what each document covers

Check the exact module model, product-warranty term and conditions, and the power guarantee’s threshold, period, measurement method, exclusions and claim process. Inverter, battery, mounting, installation and labour may each have different terms. Ask who handles a fault, who pays for transport or replacement, and which documents are required.

Separate commercial warranties from legal rights

In Spain, Royal Decree-Law 7/2021 sets a three-year period for a lack of conformity in new goods sold to a consumer to become apparent, for contracts covered by that rule and from delivery. How it applies to a contract combining supply and installation depends on the contract and circumstances. It is not the same as a commercial performance guarantee and does not promise a particular amount of electricity.

Keep evidence and get terms in writing

  • Quote, invoice, model numbers and datasheets.
  • Full product and power-guarantee terms, not only marketing summaries.
  • Commissioning documents and maintenance conditions.
  • Logs and photos of a problem before dismantling or repair.

Check the applicable terms before buying or making a claim; ask a consumer-advice service about legal questions on your contract. For a new system, see our home solar service. This guide is general information, not legal advice.

Legal source: Spain’s Royal Decree-Law 7/2021, consolidated text, especially Article 120.