Solar Backup for Load Shedding: What Size Do You Need?

How load shedding actually hits your home

Load shedding does not just switch off your lights. It cuts power to everything at once and usually for a block of two to four hours at a time, sometimes more than once a day. Your fridge stops cooling, your Wi-Fi router goes dead, the gate motor and alarm lose power, and anyone working or studying from home is suddenly offline.

The aim of a solar backup is not to power your whole house as if nothing happened. It is to keep the things that matter running smoothly through each slot, so a four-hour outage feels like a minor inconvenience rather than a crisis. Once you frame it that way, the sizing question becomes much easier to answer.

The three system types, explained simply

Before you can size anything, it helps to know the three broad ways a solar system can be set up. Each behaves very differently when the grid goes down.

• Grid-tied (no backup): Panels feed your home and can cut your electricity bill, but when the grid drops, the system shuts off for safety. Cheapest to install, but it gives you nothing during load shedding.
• Hybrid (battery backup): The most popular choice. Panels charge a battery and run your home, and when the grid fails the system switches over automatically so your essentials stay on. This is what most people mean by a solar backup.
• Off-grid: A larger system with enough battery and panel capacity to run independently of the grid entirely. It is the most expensive route and usually overkill if you simply want to ride out load shedding.

What you actually need to keep running

The single biggest factor in your system size is what you choose to back up. Light, low-draw items are cheap to keep on. High-draw items that make heat are expensive and will drain any battery quickly.

Start by deciding what genuinely has to stay on, and be honest about what can wait until the power returns.

• Back up first: lights, Wi-Fi and router, fridge or freezer, phone and laptop charging, and security such as the gate motor, alarm and cameras.
• Leave off the battery: the geyser, the oven and stove, and air conditioning. These are heavy loads that will eat through a battery in minutes and blow up the cost of your system.

Battery sizing and what each option covers

Batteries are measured in kilowatt-hours (kWh), which is simply how much energy they can store. Bigger battery, longer runtime, higher price. Here is a realistic guide to our common options and what each one comfortably handles during an outage.

We fit trusted battery brands including Pylontech, Hubble, Freedom Won and Volta, so the right capacity can be matched to your home rather than the other way around.

• 2.4kWh (from R15,000): Keeps your lights, Wi-Fi and phones running for roughly 2 to 4 hours. A solid starter for getting through a single load-shedding slot.
• 5kWh (R25,000 to R40,000): Covers your essentials plus the fridge for around 4 to 8 hours. The sweet spot for most family homes.
• 10kWh and up (R50,000 to R80,000): Can run a whole home for roughly 8 to 16 hours, including longer outages or back-to-back slots.

A simple way to work out your own size

You do not need to be an electrician to get a rough number. List the items you must keep on, estimate the watts each one draws, add them up, then multiply by the number of hours of backup you want. That gives you the energy you need in watt-hours, which you then convert to kWh by dividing by 1,000.

Here is a worked example for a typical home that wants four hours of cover:

• LED lights: about 200W
• Wi-Fi router and a laptop: about 150W
• Fridge or freezer: about 150W on average
• Phone charging and small electronics: about 100W
• That totals roughly 600W. Over four hours that is 600 x 4 = 2,400 watt-hours, or 2.4kWh.

Why a battery beats a generator

Plenty of homes already own a petrol or diesel generator, and they do switch the lights back on. But a solar battery backup wins on the things that matter day to day.

A generator is loud, needs fuel you have to buy and store, and someone has to go outside and start it every time the power drops. A solar battery is silent, switches over automatically the moment the grid fails, needs no fuel, and when paired with panels it also cuts your monthly electricity bill rather than adding a diesel cost. It works for you even when there is no load shedding.

Do you need to register your solar system?

If your system connects to the grid at all — which covers every grid-tied and hybrid backup setup — it has to be registered with your electricity distributor, whether that is Eskom or your local municipality. Systems with no grid connection at all, meaning true off-grid setups, are exempt. Registration keeps your installation legal, safe, and properly metered, and it is a step a reputable installer should never skip.

There is a real reason to do it sooner rather than later. Eskom has waived its registration and connection fees and is offering a free smart meter, worth up to R10,000 for urban residential customers, on qualifying systems up to 50kVA — currently until 30 September 2026. These rules and deadlines do change, so confirm the current position with your distributor before you rely on them. We handle the paperwork and the required Certificate of Compliance as part of every installation.

Start small and expand later

You do not have to buy a whole-home system on day one. These setups are designed to grow with you. You can start with one or two panels and a small battery to cover your most important loads, then add more panels and battery capacity later as your budget allows.

It means you can spread the cost over time without throwing away your initial investment, and every part you fit is backed by real warranties: 10 years on the battery, 25 years on the panels, and 2 years on our workmanship.

Getting the right size for you

The honest answer to "what size do I need" is that it depends on your home, your essentials and how long you want to stay powered. A small flat with a 2.4kWh battery and a family home running a fridge on 5kWh have very different needs, and oversizing wastes money just as much as undersizing leaves you in the dark.

The simplest next step is to let us look at your actual loads and your typical load-shedding schedule, then size a system that fits. Book a free consultation and we will give you a clear, honest recommendation with no pressure.