Solar and backup power: what to check when you buy
A home with solar panels, an inverter or a battery can save you money, but only if the system is yours, safe, and properly registered. Before you sign an offer, find out who owns the equipment, ask for the paperwork, and check what the system can actually run. This is where buyers get caught out.
Who owns the system?
Start here. The seller may have paid for the system outright, financed it with a loan, or leased it from a supplier. Ask for the invoice and any finance or rental agreement. If the equipment is leased or still financed, find out whether the agreement passes to you on transfer, what the monthly cost is, and who is liable if something fails. Do not assume the equipment is included in the sale. Check that the offer to purchase lists it, so it is clear what stays.
Is it registered?
Eskom says generators under 100 kVA that run alongside its supply must be registered, even if they send nothing back to the grid. In areas where the municipality supplies power, the owner registers with the municipality, as the national energy regulator requires. A system that is fully off-grid does not have to register, but the owner must be able to show it runs independently.
Eskom’s list of what it expects includes a certificate of compliance, equipment that meets the standard called NRS 097-2, and an installation report signed by a registered engineer or technologist. Ask the seller for proof that registration was done, and ask your conveyancer to check what your municipality expects.
Enforcement is a matter of dispute. Some groups argue that there is no legal power to fine owners for not registering, so do not assume that penalties are settled either way. Eskom ran a free registration campaign that was due to end on 31 March 2026 unless extended, so do not count on free registration. Ask the supplier or the municipality what it costs today and who pays.
Check the electrical certificate
Adding solar is an addition to the electrical installation. The Electrical Installation Regulations require a certificate of compliance for at least the work that was done. A change of ownership may not be allowed if the certificate is older than two years. One source says the wiring and switchgear are covered by the certificate but the panels themselves are not. Either way, you need a valid certificate on transfer. Ask the seller to supply a current one that mentions the solar work, and ask whether the cost of getting it is theirs. See compliance certificates when selling.
Questions about the equipment
- What does it run? Ask what the system powers. Some run lights and a TV during outages, and some run an entire house. Ask what happens with a geyser, oven or pool pump.
- How big is the battery? Ask how many hours of backup you can expect, and what the supplier says about battery life.
- Who installed it, and when? Ask for the installer’s name, contact details and proof of qualifications.
- Is there a warranty? Check how long it lasts, what it covers, and whether it passes to a new owner.
- What is the roof like? Panels sit on the roof, so ask about its age and condition. A leaking roof is expensive to fix with panels in the way.
- Is the system monitored? Ask for log-in details and a record of how much power it has produced.
Back-up power does not have to mean solar. If the home has a generator or gas, ask the same questions about ownership, safety and certificates. For gas, a certificate of conformity applies when ownership changes, if the property has a gas installation.
Sectional title and estates
In a sectional title scheme or a security estate, ask the body corporate or the homeowners’ association about the rules. Roof space and external walls are often common property, and a scheme may have rules on what you can fit and where. Ask for the rules before you commit.
Insurance and cost
Tell your insurer about the system and ask whether it is covered. Panels, inverters and batteries are expensive to replace. See homeowners insurance explained. If you plan to add solar yourself after you buy, build the cost into your budget now. Use the bond repayment calculator to see what a larger bond would cost, and compare the saving on your electricity bill.
What to do next
- Ask the seller for the invoice, warranty, registration proof and a current certificate of compliance.
- Put the equipment and any finance in the offer to purchase. Read offer to purchase: what to check.
- Take the installer’s details and, if in doubt, get an independent electrician to inspect the system.
- Check the costs against your budget with the affordability calculator.
This article is general information for South African readers, not legal, financial or tax advice. Rules and rates change, so check your own situation with an attorney, your bank or a tax practitioner. Our property calculators can help you work out the numbers.