Picture this scene, year seven. The inverter stops working. The company that installed it no longer exists, or changed business, or doesn't answer. You call another one, and the first thing they ask is: which inverter is it, how is the system put together, what warranty did it have?
If you have the folder, that conversation takes ten minutes and the service call is a formality. If you don't, someone is going to reconstruct your installation by looking at cables, the warranty will be hard to invoke without a serial number, and all of that gets billed by the hour.
Of the whole process of installing panels, this is the least exciting topic. It's also the one that determines whether a year-seven problem is solved in a week or turns into an ordeal. The documentation is part of what you bought, not a favour from the installer. Here's the list.
The list
1. The installation diagram. A drawing of how the system is connected: panels, how they're grouped, inverter, protections, and the connection point to your board. You don't need to understand it. The next technician who opens the board does.
2. The equipment list with serial numbers. Make, model and serial number of panels, inverter and batteries if there are any. The serial numbers are the key to the warranties: without them, you own equipment whose purchase date you can't prove.
3. The warranties, in writing and kept separate. There's a distinction here that gets muddled constantly and is worth keeping clear:
- Manufacturer warranties: those of the equipment. Inverter, panels (which also carry their long-term performance warranty), batteries. Honoured by the manufacturer or its representative.
- Installation warranty: that of the work. Fixings, cabling, board, roof watertightness. This one is honoured by your installer, and it has to be in writing, with scope and duration. "Just call us if anything comes up" isn't a warranty; it's a sentence.
4. Proof of the utility paperwork. The document showing your system is authorised to export and your meter is bidirectional. It formalises your status as a generating user. And if you sell the house tomorrow, this paper matters to the buyer too.
5. The monitoring credentials. Username and password for the inverter's platform, registered to your email. It's more common than it should be for monitoring to hang off the installer's account, and the day that company disappears, your history disappears with it.
6. The manuals. The user manuals for the inverter and the batteries. Paper or PDF, doesn't matter. Just have them.
7. Invoice and receipt. Obvious, but we'll say it: the invoice is also your proof of the purchase date, from which all warranties run.
When to ask for it
Short answer: before the final payment. Not out of distrust, out of good order. The natural close of a project is: documentation handed over, final verification, balance paid. The pack is usually assembled as a closing routine; asking for it at that moment simply keeps the natural order of things.
Has your system been installed for a while and this list made you realise you have almost none of it? Ask for it anyway, today. Most of it can be reconstructed: the diagram can be surveyed, the serial numbers are on the equipment, the monitoring can be migrated. It costs more than having received it on day one, but vastly less than needing it and not having it.
Your folder checklist
- Installation diagram
- Equipment with make, model and serial number
- Manufacturer warranties, per item
- Installation warranty in writing, with years and scope
- Proof of the utility paperwork
- Monitoring access with your email as the account holder
- Manuals
- Invoice
Your system will last 25 years. Companies, technicians, apps and even the manufacturer of your inverter may change in that time. The folder is what makes your system independent of all of them. What makes it genuinely yours.