What SA Homeowners Should Ask When Buying a Solar System

1. It’s about balance, not just panels

In the early days of load shedding, many South Africans rushed to install solar systems simply to keep the lights on. Those quick-fix systems were mostly designed for backup power, not long-term efficiency or savings.

Now that load shedding is less frequent, homeowners are taking a more strategic approach. The focus has shifted from short-term survival to sustainable energy planning.

When buying solar, it’s important to understand that your panels, inverter, and battery all work together as one system. You can’t just load your roof with extra panels and expect your inverter or battery to handle it automatically. Every component has a specific capacity and function:

• Solar panels generate power.
• The inverter converts that power into usable electricity for your home.
• The battery stores excess power for later use.
  
  

If these parts are not properly matched, you could waste the energy you produce — or worse, overload your system.

A balanced setup ensures your home uses the maximum amount of solar energy possible during the day, stores the right amount for night-time use, and still draws less from Eskom. That’s where the real return on investment lies.

Before installing solar, ask your provider to analyse your household’s daily usage, roof potential, inverter capacity, and battery size. The goal is to design a system that gives you both reliable backup and efficient everyday savings — not just a roof full of panels.

2. “Cheap” can cost a lot more in the long run

Cut-rate solar installs are a real problem in South Africa. Some installers save on cost by using low-grade cables, non-approved inverters, poor mounting hardware, or by skipping key safety steps. That can lead to system failure, expensive repairs, fire risk, or an insurer refusing a claim if the system is non-compliant or poorly installed. Insurers and industry bodies have repeatedly warned homeowners about fly-by-night operators and the risk of rejected claims for non-compliant work.

Actionable checklist for homeowners before you sign:

• Ask for proof of company registration, tax compliance (SARS), and a physical business address.
• Request evidence of trained staff on site (registered installation electrician present during wiring) and PV-specific competency (PV GreenCard or equivalent).
• Get a written list of component brands and model numbers for panels, inverter(s), batteries, mounting, and cabling. Verify those models are approved for SSEG use if required by your distributor.
• Confirm who issues the Certificate of Compliance (COC) and any as-built reports (PV GreenCard as-built report where available). A COC must be issued by a registered installation electrician.
  
  

3. Registration and rules matter more than many homeowners realise

You must register your solar system under Small-Scale Embedded Generation (SSEG) rules. This is not optional in Eskom areas. Registration is a legal and technical requirement because the distributor needs to ensure safety, anti-islanding, correct metering and that your system will not harm the grid.

Municipalities (for example City of Cape Town) and Eskom publish step-by-step SSEG processes and require permission, network studies for some sizes, and approved equipment and settings. Failure to register can lead to the system being disconnected, fines, or problems with insurance.

Practical points to check with your installer:

• Confirm who will handle the SSEG application and registration with your municipality or Eskom and include it in the contract.
• Ask whether your system needs a grid study (larger systems or constrained feeders often do) and what additional costs that creates. City and Eskom rules specify when grid studies are required.
• Ensure the inverter has the required anti-islanding and export limit settings and that protection settings will be configured correctly on commission. NRS standards and local distributor rules define these technical requirements.
  
  

4. Figure out your usage and future plans now — precisely

Sizing a system by guesswork is a recipe for disappointment and expensive retrofits. Review 12 months of bills and export the kWh per month and, if available, time-of-use patterns (day versus night). Consider likely changes in the next 3–7 years: adding an electric vehicle, installing an electric oven, pool pump timing, or a home office. These changes change both peak loads and daily energy profiles.

How to make the analysis useful:

• Ask your installer for a load profile analysis based on your actual bills and on-site measurements (sometimes installers offer a short monitoring period to capture real usage).
• Ask whether the proposed system is scalable: can you add batteries or extra panels later without replacing the inverter or rewiring major parts of the system? If not, factor the future upgrade cost into today’s ROI.
• If you plan an EV, get a quote for EV charging scenarios and how that will affect battery sizing and expected payback. A properly sized system today avoids costly upsizing later.
  
  

Helpful reference: installers who use a PV GreenCard/process or accredited design practice typically include documented load analysis in their proposal.

5. Interview your installer like you are hiring a contractor

Treat the installer conversation as a formal contractor evaluation. Beyond price, these are the questions that will protect your investment and safety:

Essential questions to ask and request in writing

• Components: What are the exact panel, inverter, battery, mounting and cable brands and models? Are they locally supported and approved for SSEG registration? Provide datasheets.
• Certifications: Do you or your team hold PV GreenCard certification, and can you show a PV GreenCard as-built report or equivalent? Who will issue the COC?
• Compliance & registration: Will you handle SSEG registration, grid studies, municipal permits and meter changes? What are the expected fees and timelines?
• Operation during grid failure: What will the system do during a grid outage? Which loads can run from the battery and for how long? Will the inverter automatically island and provide backup? Ask for a scenario example (e.g., lights, fridge, Wi-Fi for X hours).
• Warranties & maintenance: What are the manufacturer warranties and does the installer provide workmanship or performance guarantees? Who handles warranty claims? How is monitoring set up and what maintenance is advised?
• Insurance & safety: Will the solar installation comply with insurance requirements and provide the paperwork your insurer needs if a claim arises? Will the installer confirm installation with your insurer if required?
  
  

Get these answers in writing and include them in the contract. If an installer resists providing component model numbers, test data, or a written scope, walk away.

6. Don’t forget “what happens at night or on low-sun days”

Solar panels generate during daylight but households need energy 24/7. If you want resilience you must design for it, not hope for it.

Key design tradeoffs to consider:

• Battery capacity vs cost: Batteries add resilience but are still a significant portion of system cost. Decide whether you want overnight backup for critical loads only (fridge, router, lights) or full household autonomy overnight. The first option needs much smaller batteries.
• Hybrid design: A well-designed hybrid inverter and battery system will prioritise daytime self-consumption, charge the battery efficiently, and allow controlled export where permitted. However, every inverter has maximum PV input and battery charge rates; adding panels beyond the inverter’s input capacity will not increase usable energy unless the inverter is upgraded or a PV-coupled battery strategy is used. In short, panels, inverter and battery must be matched.
• Load prioritisation: Ask for a load-priority plan from your installer: which circuits will be on during an outage, which will be off, and how long each will run with the specified battery? This gives realistic expectations instead of vague promises.
• Seasonal variation: Solar production varies by season. A system that looks generous on a summer day may not meet needs in winter without a larger battery or adjusted export/import strategy.
  
  

Simple scenario test to ask for: “With the proposed panel and battery size, how many hours will essential loads run during an average winter evening?” The installer should be able to model that for you.