How long each part lasts
| Part | Expected life | What to plan for |
|---|---|---|
| Panels | 25 years or more (Energy Saving Trust) | Gradual output loss, covered by the power warranty |
| Inverter | Replace after around 12 years (Energy Saving Trust) | One replacement during the system’s life |
| Mounting and cabling | Should match the panels | A check whenever the roof is worked on |
Monitoring: the cheapest maintenance there is
Most inverters come with an app or web portal. Once a month, compare generation with the same month last year and with the estimate on your quote. Some inverters can warn you by email if the system fails. A sharp drop usually means an inverter fault; a slow decline in one part of the array may be new shading or soiling.
Cleaning: only when it helps
Tilted panels are rinsed by rain. Cleaning is worth paying for when output has dropped and you can see dirt, lichen or bird droppings. Never climb on the roof yourself. Use a firm with safe access and soft, water-fed brushes, and check your panel warranty for any cleaning conditions. Bird mesh around the array edges, fitted at installation, stops nesting underneath.
Paperwork to keep
- The MCS certificate (needed for export payments and useful when you sell).
- The electrical installation certificate.
- Panel, inverter and workmanship warranties, plus any insurance-backed warranty documents.
- Datasheets and the generation estimate.
Keep your export meter readings and SEG statements too; they are the quickest way to spot a drop in output.
“Solar is high maintenance.” It isn’t: the inverter is the one part you should expect to replace. See solar inverters.