Solar Backup Power for Your Home

The one thing

Decide what you need to keep running, and for how long, before you choose any equipment. Backup power ranges from an R800 box that keeps the Wi-Fi on to a R150 000 solar system that runs a whole house. Most people need something in between, and many overspend on the wrong thing. Start with the list of what matters most in your home, then choose. §1.2 compares the options, and §1.6 helps you write a first plan.

Power Cuts in South African Homes

South African homes lose power for several reasons:

• Load-shedding: planned, rotating cuts announced by Eskom when the national grid cannot meet demand. At its worst (2022 and 2023), many areas were without power for eight to twelve hours a day, in blocks of two to four hours. It eased greatly from 2024, but it can return whenever the grid is under strain.
• Load reduction: cuts in some areas, often in the evening, where too much electricity is used or too little is paid for, or to protect overloaded equipment.
• Unplanned outages: cable theft, a failed transformer or substation, storms, floods and fires. These can last from an hour to several days, with no warning.
• Municipal faults and maintenance: planned work, announced in advance, and repairs.

A power cut costs a household more than inconvenience: food spoils in the fridge, a child cannot study online, a home business loses customers, a security alarm and electric fence go flat, and someone who works night shifts cannot sleep through a noisy generator next door. Knowing which of these matters most in your home is the start of a good plan.

The Options

Rough costs are for late 2026.

• Router UPS. Runs a Wi-Fi router or fibre box for 3–8 hours. R600–R1 500. You set it up (it plugs in).
• Portable power station. Runs a fridge, lights, TV, laptop and phones for 2–6 hours, depending on size. R4 000–R25 000. You set it up (it plugs in).
• Inverter and battery on an essentials circuit. Runs lights and plugs for the fridge, TV, Wi-Fi, gate motor and alarm for 4–10 hours. R25 000–R70 000 installed, by a registered person, with a CoC.
• Solar hybrid system. As above, plus daytime use from the sun; can cut the electricity bill. Lasts through most outages, and days with good sun. R90 000–R200 000 installed, by a registered person, with a CoC; registered with the municipality.
• Generator. Runs almost anything, if big enough, for as long as there is fuel. R3 000–R25 000, plus fuel. You set it up, outdoors; a changeover switch is installation work.
• Gas. Cooking, hot water and some lights, for as long as there is gas. R1 000–R5 000 for a cooker. You set it up if portable; fixed installations by a registered gas installer.

Each has a place:

• A router UPS is the cheapest, most useful first step for anyone who works or studies online.
• A portable power station is a large battery with a built-in inverter and plugs: no installation, and it moves with you, so it suits tenants and people in flats.
• An inverter and battery wired into the house runs selected circuits automatically when the power fails.
• A solar hybrid system adds panels, so the battery recharges from the sun and the house uses less electricity from the grid.
• A generator runs for as long as you feed it fuel, but it is noisy, needs servicing, and can kill: by carbon monoxide if run indoors, and by “back-feeding” if wrongly connected (Chapter 11).
• Gas cooking and a gas geyser take the biggest loads off any backup system.

Matching an Option to a Home

Three questions narrow the choice quickly:

1. What must keep running? The Wi-Fi only? The fridge and lights? A home business? A medical device?
2. For how long? A two-hour outage, a four-hour block, or a day without power?
3. What can you spend, and do you own the home? A tenant usually cannot install a fixed system without the owner’s written permission; a portable power station goes with them when they move.

The likely best first step for each kind of household:

• A student or someone working from home, in a flat. A router UPS, then a small power station.
• A family that needs the fridge, lights and TV. A portable power station of about 1 kWh, or an inverter and battery.
• A home business (a salon, a bakery, a spaza). An inverter and battery on an essentials circuit, sized for the business’s loads.
• A homeowner who wants lower bills as well as backup. A solar hybrid system.
• Someone who depends on a medical device at home. Talk to the doctor and the device’s supplier first: many devices need a particular kind of backup, and some suppliers lend backup units.

Worked Example 1.1 — Lindiwe’s first step

Mrs Lindiwe Ndlovu, 46, is a nurse in Pietermaritzburg who works night shifts. Her son Lwazi, 17, studies online. When the power goes, the fibre box and Wi-Fi router go dead, and Lwazi loses his lessons. Her neighbour suggests a generator. Lindiwe asks the three questions. What must keep running? Above all, the Wi-Fi; then the fridge and a light. For how long? Usually two to four hours. What can she spend? Not much this month, and she rents. She buys a router UPS for R850 that powers both the fibre box and the router, and plans to save for a portable power station for the fridge and lights (Chapter 7). A generator would be noisy when she sleeps after a night shift, and she cannot leave one running unattended outdoors in a rented townhouse complex.

The lesson: the right first step is the smallest one that solves the most important problem.