Estate agents list solar panels as a feature and leave it there. For a buyer they are a question: who owns them, do they work, what do they earn, and what will they cost? None of that appears in the listing, and the conveyancing process will only ask about the first part. Here is what to ask the seller, and what the answers mean.
1. Does the seller own them?
Some panels fitted between about 2010 and 2015 were “free solar”: a company fitted them at no cost and kept the roof under a lease, typically for twenty-five years, in return for the subsidy payments. If that is the case here, you are buying a house with a lease on its roof. The lease transfers to you, the company’s rights to access and repair the roof come with it, and some mortgage lenders have conditions about it.
Ask directly: “Do you own the solar panels outright, or is there a roof lease or agreement with a solar company?” If there is a lease, get a copy early and have it read. The guide on free solar and roof leases explains what to look for in it.
2. Are they on the Feed-in Tariff, and does it transfer?
A system fitted before April 2019 is probably registered for the Feed-in Tariff, which pays the owner for every unit generated for twenty or twenty-five years from installation. Those payments belong to whoever owns the system, so on a sale they pass to the buyer, provided the transfer is done properly with the energy supplier that pays them. The seller should be able to tell you the rate, the end date and what it earned last year. On an older system with a high rate that can be a four-figure sum a year, and it is worth more than the panels.
Systems fitted since 2019 can be registered for export payments instead, which are smaller and depend on the supplier. Either way, ask for the last year’s statements.
3. Do they work?
The seller’s answer will be yes. Ask for evidence: the generation meter reading now and any earlier reading or statement, so you can see what it produced over a year. The guide on the two meter readings explains the comparison; for a south-facing system in most of England, somewhere around 850 to 950 kWh a year per kWp is healthy, less in Scotland, less again if the roof faces east or west.
A system that has produced far less than that, or whose meter has not moved, is a system with a fault the seller may not know about. That is a negotiating point, not a reason to walk away, but it has to be found before exchange.
4. How old is the inverter?
The panels last twenty-five years or more. The inverter, the box that turns their output into mains electricity, lasts ten to fifteen. On a house with a 2012 system the inverter is either already replaced or due, and replacing it is a four-figure job. Ask when it was fitted and whether it has been replaced. If the system is over ten years old and the inverter is original, budget for it.
5. What paperwork is there?
Ask for:
- the MCS certificate, which proves the installation was done to the standard that the subsidies and the export payments require;
- the network operator notification (the G83 or G98 form, depending on age), which shows the connection was declared;
- the installation handover pack, with the warranties for panels, inverter and workmanship, and who to contact;
- the generation meter readings or FiT statements;
- any service or maintenance records, especially an inverter replacement.
Missing paperwork is common and not fatal, but the MCS certificate matters: without it, registering for export payments is difficult. If the seller cannot find it, the original installer, if still trading, or the MCS scheme itself can usually reissue it.
What to do next
Put the five questions to the seller in writing, through the agent, before you instruct a survey. The answers take the seller an hour to gather and tell you whether you are buying an asset, a repair or a lease. If the system is more than a few years old and the house is a serious prospect, a desk-based Health Check on the readings and the paperwork costs less than a day’s worth of the mistake it prevents.