Solar Calculator
South Africa
Enter your monthly electricity usage (from your bill) and get an instant solar system recommendation — panel count, battery size, inverter rating, and a realistic cost estimate for South Africa.
Key takeaways
- ✓South Africa averages 5 peak sun hours/day — one of the best solar resources in the world.
- ✓A typical 600 kWh/month home needs a 4–6 kWp system (8–12 panels) to offset most of its bill.
- ✓LiFePO4 batteries last 10+ years and 4,000+ cycles — the only sensible choice for SA heat.
- ✓With Eskom at 271c/kWh and rising, most systems pay back in 5–8 years then generate free power.
Solar system size calculator
Find this on your Eskom or municipal electricity bill under “units consumed”.
Offset most of your bill — the most popular choice for SA homes.
Stage 4 load shedding = 4h blocks. Stage 6 = up to 6h.
Data: Effective 1 April 2026 · Eskom tariff 271c/kWh (April 2026) · 5 peak sun hours (SA average) · Manufacturer spec sheets · See methodology
Solar system size guide for South Africa
Not sure where to start? This table gives a quick reference for common home sizes and typical system recommendations. Prices include panels, inverter, battery, and installation — sourced from SA supplier quotes (April 2026).
Small (1–2 kWp)
R15,000–R35,000Usage
< 300 kWh/month
Panels
2–4 panels
Battery
5 kWh
Inverter
3 kVA
Flats and small homes with minimal usage
Medium (3–5 kWp)
R35,000–R60,000Usage
300–600 kWh/month
Panels
6–10 panels
Battery
10 kWh
Inverter
5 kVA
Average suburban home
Large (6–10 kWp)
R60,000–R100,000Usage
600–1,000 kWh/month
Panels
11–18 panels
Battery
15–20 kWh
Inverter
8 kVA
Large homes, pools, under-floor heating
Extra large (10+ kWp)
R100,000+Usage
> 1,000 kWh/month
Panels
18+ panels
Battery
20+ kWh
Inverter
10+ kVA
Large homes or small businesses
How solar sizing works in South Africa
Solar sizing is a three-step process: calculate your energy needs, design the panel array, then size the battery bank. Each step feeds into the next.
Step 1 — Energy needs
Your monthly kWh from the electricity bill tells you how much energy your home uses. Divide by 30 to get daily kWh. This is your target — how much solar needs to generate to fully offset your bill.
Step 2 — Panel array (kWp)
South Africa averages 5 peak sun hours per day, but system efficiency (inverter losses, soiling, shading, temperature derating) reduces real output to about 75% of ideal. So each kWp of panels generates approximately 3.75 kWh/day usable. Divide your daily kWh target by 3.75 to get your system size in kWp.
Step 3 — Battery bank (kWh)
Batteries cover usage at night and during load shedding. Size the battery to your overnight load (typically 30–50% of daily usage) plus desired backup hours. Always add 25% to account for 80% DoD (depth of discharge) — you should not drain LiFePO4 batteries below 20% state of charge.
Step 4 — Inverter rating (kVA)
The inverter must handle your peak simultaneous load — the maximum wattage you could run at once. Add up the wattage of everything you might run at the same time (fridge 150W + lights 200W + TV 100W + laptop 65W = 515W). Add 25% surge margin and round up to the next inverter size (typically 3, 5, or 8 kVA).
Which battery type should you choose?
In 2026, LiFePO4 (lithium iron phosphate) is the clear recommendation for South African home installations. Here is why it beats the alternatives:
| Type | Lifespan | Verdict |
|---|---|---|
| LiFePO4 | 10–15 years / 4,000+ cycles | ✅ Best choice |
| Li-NMC (standard lithium) | 5–8 years / 2,000 cycles | ⚠️ Degrades faster in SA heat |
| Lead-acid (AGM/GEL) | 2–4 years / 500 cycles | ❌ Poor value long-term |
| Saltwater / flow | 15+ years | ⚠️ Very limited SA availability |
Is there still a solar tax rebate?
Not for households. The individual rooftop solar rebate (Section 6C — 25% of panel cost, capped at R15,000) applied only to new panels brought into use between 1 March 2023 and 29 February 2024. It cannot be claimed for installations after that window, and it was a once-off incentive that has not been renewed.
What this means in 2026:
- ✓ Budget for solar at full cost — no SARS rebate reduces it for households
- ✓ Businesses and sole proprietors may still claim the Section 12B / 12BA renewable-energy asset allowance — ask a tax practitioner
- ✓ The real household saving is the electricity you stop buying at 271c/kWh — which is what this calculator works out
Frequently asked questions
How many solar panels do I need for my South African home?
The number of panels depends on your monthly electricity consumption (from your bill) and how much of it you want to offset with solar. South Africa averages 5 peak sun hours per day. A 550W panel generates roughly 2.75 kWh/day (550W × 5 hours × 100% — adjusted for 75% system efficiency = ~2.1 kWh usable per panel per day). Divide your daily kWh target by 2.1 to get the panel count. Our calculator does this automatically.
What size solar system do I need?
A typical South African household using 600–900 kWh/month needs a 5–8 kW solar system with 10–15 panels. Small homes using 300–500 kWh/month can get by with a 3–5 kW system. The system size (kWp) is the total peak power of all panels combined.
How much does a solar system cost in South Africa in 2026?
A complete grid-tied solar system (panels + inverter, no battery) costs roughly R2,500–R3,500 per installed kWp in 2026. A 5 kWp system runs R12,500–R17,500 installed. Adding LiFePO4 battery storage adds R8,000–R15,000 per 5 kWh of capacity. A full off-grid or hybrid system (5 kWp solar + 10 kWh battery) typically costs R45,000–R80,000 installed.
What is the payback period for solar in South Africa?
At the current Eskom Homelight tariff of 271c/kWh and with typical system costs, most South African solar installations pay back in 5–8 years. After payback, the system generates free electricity for its remaining lifespan (25+ years for panels, 10–15 years for LiFePO4 batteries). Payback accelerates with each Eskom tariff increase.
Can I go completely off-grid in South Africa?
Yes, but it is expensive and usually unnecessary for urban homes. True off-grid requires enough battery capacity to cover 2–3 days of cloudy weather, plus a generator backup — typically doubling system cost. Most South Africans are better served by a hybrid or grid-tied system with battery backup for load shedding, which keeps the grid as a safety net while dramatically reducing the Eskom bill.
Does solar still make sense now that load shedding has reduced?
Yes — the case for solar in South Africa is primarily economic, not just load-shedding relief. With Eskom increasing tariffs by 8.76% in 2026 and similar increases expected annually, every unit generated by your solar system saves you money at the current (and growing) tariff. The financial case strengthens every year even if the grid becomes more stable.
Can I still claim the solar panel tax rebate in South Africa?
No — not as a household. The individual rooftop solar rebate (Section 6C, 25% of panel cost capped at R15,000) applied only to new panels brought into use between 1 March 2023 and 29 February 2024, and was not renewed. Businesses and sole proprietors may still qualify for the Section 12B/12BA renewable-energy asset allowance — check with a tax practitioner. For households in 2026, the saving is the Eskom electricity you no longer buy, not a SARS rebate.
How do I read my electricity bill to use this calculator?
Look for 'kWh consumed' or 'units used' on your Eskom or municipal electricity bill. This is your total electricity consumption for the billing period (usually 30 days). Divide by 30 to get daily kWh usage, or enter the monthly total directly into the calculator.
Was this page helpful?
Read next
All guides →Free Solar Calculator or Professional Quote — Which Comes First?
Why a free solar calculator is the right first step for sizing and budget, and why a professional quote is still essential before you sign anything.
Read guideAre Solar Panels Worth It for a South African Home in 2026?
A step-by-step guide to working out whether solar panels are worth it for your South African home — from your electricity bill to a payback figure.
Read guide