Home & Energy
Solar & Backup Power Calculator South Africa 2026
Size a solar, inverter and battery system to beat loadshedding and cut your Eskom bill — with realistic 2026 South African costs, ROI and payback estimates.
✓ Updated with 2026 rates•✓ Free & no sign-up•✓ Instant results
Solar & backup power
Live system sizing · costs · ROI · 2026
R
Eskom tariff used: R2.85/kWh
Average home: 20–40 kWh/day (check your Eskom bill)
Approximate usable north-facing roof area
Recommended system
8 kW
with 17 kWh battery · Stage 4 backup
Total investment
R362 408
Monthly savings
R3 121
Payback period
9.7 yrs
25-year savings
R573 818
Annual generation
13 140 kWh
Roof needed
56 m² ⚠
A 8 kW solar system with a 17 kWh battery costs about R362 408, saves around R3 121/month and pays back in ~9.7 years — about R573 818 saved over 25 years (158% ROI). Your 50 m² of roof is below the 56 m² this system needs.
System cost breakdown
Solar panels
R144 000
Battery
R138 125
Inverter
R25 000
Installation & COC
R55 283
Solar sizing rules of thumb (South Africa)
- Each 1 kW of panels needs about 7 m² of north-facing roof
- 1 kW produces roughly 4.5–5.8 kWh/day depending on province
- Panels ~R18,000/kW · lithium battery ~R8,500/kWh · hybrid inverter ~R25,000
- Grid-tied solar typically pays back in 5–7 years, then runs near-free for 20+ years
Solar generation by province (2026)
| Province | kWh/kW/day | Eskom tariff |
|---|---|---|
| Gauteng | 4.5 kWh | R2.85/kWh |
| Western Cape | 5.2 kWh | R2.95/kWh |
| KwaZulu-Natal | 4.8 kWh | R2.80/kWh |
| Eastern Cape | 4.6 kWh | R2.75/kWh |
| Free State | 5.0 kWh | R2.70/kWh |
| Mpumalanga | 4.7 kWh | R2.72/kWh |
| Limpopo | 5.3 kWh | R2.68/kWh |
| North West | 5.1 kWh | R2.70/kWh |
| Northern Cape (best sun) | 5.8 kWh | R2.78/kWh |
Estimates based on 2026 average costs and irradiance. Your actual sizing, quotes and savings depend on your roof, appliances and installer. This is an independent estimate, not a quote.
Why solar beats loadshedding in South Africa
With ongoing loadshedding and Eskom tariffs rising well above inflation, a solar system is increasingly the most cost-effective alternative for South African homes and businesses. A well-sized system keeps the power on during outages while cutting — and eventually eliminating — your daytime electricity bill.
Beat loadshedding
Battery storage keeps lights, Wi-Fi and the fridge running through Stage 1–8 outages.
Lower your bill
Offsetting daytime usage can reduce electricity costs by 70–100% over time.
Strong long-term ROI
Most grid-tied systems pay for themselves in 5–7 years, then run near-free for 20+ years.
Adds home value
A certified, paid-off system typically lifts property value by around 3–5%.
Solar system components & typical 2026 costs
Solar panels
Convert sunlight to electricity. Around R18,000 per kW installed; each 1 kW needs roughly 7 sqm of roof.
Battery storage
Stores power for night use and loadshedding. Lithium (LiFePO4) costs about R8,500 per kWh and lasts longest.
Hybrid inverter
Converts DC to AC and manages grid, panels and battery. Typically R20,000–R30,000 depending on size.
Installation & COC
Professional wiring, mounting, commissioning and a Certificate of Compliance for safety, insurance and resale.
Inverter vs full solar vs generator
Backup inverter + battery
R40,000–R90,000. Keeps you running through outages, but you still recharge from the grid so your bill stays the same.
Full solar system
R120,000–R250,000. Panels, hybrid inverter and battery both beat loadshedding and cut your Eskom bill.
Generator
R8,000–R40,000 upfront, but noisy, high-maintenance and costly to run on fuel — best as a short-term stopgap.
Solar planning tips for South Africa
Size to your usage
Add daily kWh to size panels and battery, and peak appliance watts to size the inverter. Most homes suit a 5–8 kW system.
Mind your location
The Northern Cape and Highveld get the best solar radiation; north-facing, unshaded roofs produce the most year-round.
Battery is optional but smart
You can save with panels alone, but a battery is what actually keeps the power on during loadshedding.
Get 3+ quotes
Compare reputable, certified installers and insist on a Certificate of Compliance and clear warranties.
Frequently asked questions
Quick answers to the most common questions.
How do I size a solar and inverter system for my home in South Africa?
Start with your power usage: add up the wattage of the appliances you want to run at once to size the inverter, and your daily kWh consumption to size the panels and battery. A typical SA home uses 15–30 kWh a day and runs well on a 5–8 kW system. As a rule of thumb each 1 kW of panels needs about 7 sqm of north-facing roof and produces 4–5 kWh a day in good sun. Oversize the inverter slightly so it can handle surge loads like geysers, kettles and pumps.
What is the payback period for solar versus staying on Eskom?
For a grid-tied system that offsets your daytime usage, payback is typically 5–7 years, after which the electricity is effectively free for the panels’ remaining 20+ year life. Because Eskom tariffs have risen well above inflation (often 12%+ a year), the payback shortens every time tariffs increase. Battery-heavy backup systems pay back more slowly because batteries are the most expensive component and wear out sooner than panels.
What is the difference in cost between a backup inverter, full solar and a generator?
A backup inverter-and-battery system (no panels) keeps you running through loadshedding and costs roughly R40,000–R90,000, but it does not lower your bill since you still recharge from the grid. A full solar system with panels, hybrid inverter and battery costs around R120,000–R250,000 and both beats loadshedding and cuts your bill. A petrol or diesel generator is cheapest upfront (R8,000–R40,000) but noisy, high-maintenance and expensive to run on fuel — usually a short-term stopgap.
How big a battery do I need to get through loadshedding?
Size the battery to the energy you need during an outage, not just the power. Estimate the kW of essential loads (lights, Wi-Fi, fridge, TV) and multiply by the hours of a typical Stage 4–6 slot (about 2–4 hours). Most homes cover essentials with 5–10 kWh of usable lithium storage; running a geyser or pool pump off-grid needs far more. Lithium (LiFePO4) batteries cost more upfront than lead-acid but last longer and can be discharged deeper, making them cheaper per usable kWh over their life.
Does installing solar add value to my home in South Africa?
Yes. A professionally installed, certified solar system (with a valid Certificate of Compliance) typically adds value and makes a property more attractive to buyers worried about loadshedding and rising tariffs. Estimates commonly put the uplift at around 3–5% of the home’s value, and a paid-off system that lowers running costs is a strong selling point. Keep the COC, invoices and warranties as proof for buyers and insurers.