How Much Solar Do You Need in South Africa? A Simple 2026 Sizing Guide
Almost everyone starts by asking for a system size. 8kW. 10kW. 6kW. Size is the last decision you should make, not the first. This guide walks through how a solar system is actually sized in South Africa, what each size realistically runs, and what complete packages cost on our shop right now.
Start with your bill, not with a system size
Your municipal or Eskom bill carries the only number that matters at the start: your monthly consumption in kilowatt-hours (kWh). Find it on the statement, then divide by 30. A household using 900kWh a month is burning roughly 30kWh a day.
That daily figure tells you what the system has to replace. A quoted “8kW system” tells you nothing on its own, because 8kW describes how fast the inverter can deliver power, not how much energy you get in a day.
The three numbers that actually size a system
Every hybrid solar system is three separate sizing decisions. Getting them in the right order is most of the job.
1. The inverter, sized to your largest simultaneous load
The inverter is the ceiling on what you can run at the same moment. Add up what genuinely runs together on a bad evening: geyser element, oven, kettle, pool pump, lights, electronics. That peak, not your average, sets the inverter.
A single-phase home with a normal appliance mix usually lands on 5kW to 8kW. Add a heat pump, a borehole or a workshop and you move to 10kW or 12kW. Three-phase properties need a three-phase inverter regardless of size.
2. The battery, sized to your evening block
Your highest grid draw is usually after sunset, when the panels have stopped and everyone is home. That evening block is what you are paying peak rates for, and it is what the battery should cover.
If you use 30kWh a day and roughly 40% of it falls between sunset and sunrise, you need about 12kWh of usable storage to get through the night without touching the grid. Undersize the battery and you buy expensive evening power anyway. Oversize it and you pay for capacity that never cycles.
3. The array, sized to refill the battery on a bad day
Panels have to carry the daytime load and refill the battery, and they have to do it in winter, not in December. Size the array on a poor generation day rather than an average one, or the system runs fine for six months and disappoints for the other six.
What each system size realistically runs
| Inverter size | Typical property | Comfortably runs | Usually will not run |
|---|---|---|---|
| 5kW | Small home, 1 to 3 people | Lights, plugs, TV, fridge, Wi-Fi, small appliances, one big load at a time | Geyser plus oven together |
| 6kW | Average family home | The above plus a geyser element or an oven with headroom to spare | Pool pump, geyser and oven all at once |
| 8kW | Larger home, 4 to 5 people | Two heavy loads at once, pool pump, comfortable margin | Three-phase machinery |
| 10kW to 12kW | Large home, small business | Heat pumps, boreholes, multiple geysers, light workshop use | Industrial motors on start-up |
| Above 12kW | Commercial and three-phase | Sized on a measured load profile, not on a rule of thumb | n/a |
What a complete solar system costs in South Africa in 2026
Below are live prices from our shop, all including VAT. Each package is a matched set: hybrid inverter, battery, 600W-class panels and roof mounting. Installation, wiring, distribution boards and protection are quoted separately for your site, because those depend on your roof, your board and your distance from the DB.
| Package | Battery | Panels | Price incl. VAT |
|---|---|---|---|
| Deye 5kW | 5.12kWh | 5 | R51 430 |
| Deye 6kW | 5.12kWh | 6 | R52 100 |
| Sunsynk 6kW | 5.12kWh | 6 | R54 570 |
| Sunsynk 5kW | 5.12kWh | 5 | R55 780 |
| Sigenergy 5kW | 6kWh | 5 | R74 120 |
| Sigenergy 5kW | 9kWh | 5 | R79 640 |
| Sigenergy 6kW | 9kWh | 6 | R84 000 |
| Sigenergy 8kW | 9kWh | 10 | R104 220 |
| Sunsynk 8kW | 10.24kWh | 10 | R105 860 |
| Sunsynk 10kW | 10.24kWh | 14 | R124 180 |
| Deye 12kW | 16.0kWh | 18 | R130 260 |
| Sigenergy 8kW | 15kWh | 10 | R133 200 |
| Sigenergy 10kW | 15kWh | 14 | R152 030 |
| Sunsynk 12kW | 15.97kWh | 18 | R158 380 |
| Deye 18kW | 16.0kWh | 24 | R163 770 |
Prices change as supplier costs move. The product pages carry the current figure.
kW or kVA: is an 8kVA solar system the same as an 8kW one?
In practice, yes. kVA is apparent power and kW is real power, and the gap between them is the power factor. Modern hybrid inverters run at or very near unity power factor, so an 8kVA hybrid inverter and an 8kW hybrid inverter are almost always the same machine described two ways. If you have been quoted in kVA, compare it directly against kW figures without adjusting.
The number that does differ is the surge rating. Inverters can briefly exceed their continuous rating to start motors, and a pool pump or borehole pump draws several times its running current for a second or two. If you have motor loads, ask about surge capacity rather than only the continuous rating.
Four sizing mistakes that cost real money
- Sizing the inverter on average consumption. Averages hide the evening peak. The inverter has to survive the worst simultaneous moment, not the mean.
- Buying panels first. A big array feeding a small battery just exports cheap power and buys it back at retail after dark.
- Sizing on summer generation. A system designed around December output will disappoint from May to August.
- Ignoring the balance of system. Cabling, protection, the changeover and the DB work are real costs. A package price is not an installed price.
Frequently asked questions
What size solar system do I need for a normal South African home?
Most family homes land between 5kW and 8kW of inverter, 10kWh to 16kWh of battery, and 6 to 14 panels. The exact split depends on your evening consumption, not on the size of the house.
How much does an 8kW solar system cost in South Africa?
Complete 8kW packages on our shop start at R104 220 including VAT with a 9kWh battery and 10 panels, rising to R133 200 with a 15kWh battery. Installation is quoted separately.
Can I start small and add later?
Yes, if you choose a modular system. Battery-stackable platforms let you add storage later without replacing the inverter. Confirm the expansion path before you buy, because not every inverter supports it.
Do I need approval to install solar?
Grid-tied and hybrid systems need to be registered with your municipality or Eskom under the SSEG process, and the installation needs a Certificate of Compliance. Requirements differ by municipality, so check yours before committing.
Not sure which size fits?
Our system designer asks a handful of questions about your consumption and suggests a matched system from live stock. Or browse the full catalogue, where every product carries its price on the page.
