Solar Savings Calculator
Calculate your monthly electricity savings and payback period for a solar system in South Africa. Uses SA sun hours (4.5–6.5 hrs/day) and current Eskom tariffs with annual increases to give you an accurate long-term savings estimate.
Quick Calculator Get a fast estimate
kWp
Typical SA home: 3–8 kWp. kWp = kilowatt-peak (panel capacity).
R/kWh
Check your Eskom or municipal bill. Avg. R2.80/kWh in 2026.
%
How much solar power you use directly vs. feeding back to the grid. 70–90% is typical with a battery.
%/yr
Eskom has increased tariffs ~12–15% annually. Higher increases = faster payback.
Monthly Electricity Savings
R 1 848
Annual Savings
R 22 176
Total System Cost
R 90 000
Payback Period
4 years
Monthly Generation
825 kWh
25-Year Total Savings
R 2 956 812
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How to Use the Solar Savings Calculator
- System Size (kWp): Enter your system's peak power in kilowatts. Typical SA home: 3–8 kWp.
- Peak Sun Hours: Select your region. Most of SA gets 5.5 hrs/day. Karoo and Northern Cape get 6–6.5 hrs/day.
- Electricity Tariff: Your current R/kWh rate from your electricity bill.
- Self-Consumption: How much solar energy you use directly. With a battery, 70–90% is typical.
The Extended Calculator below adds grid-tied, hybrid, and off-grid comparisons with a 20-year savings timeline SVG. The Professional Calculator sizes your system from appliance loads and compares financing options.
Need more detail?
Extended Calculator More options, charts, and scenario comparison
R
R
Estimated Annual Saving
R 16 650
System Cost
R 190 000
Break-even
11.4 years
Coverage
56%
Daily Generation
25.0 kWh
Battery Autonomy
5.3 hrs
20-Year Cumulative Savings (Break-even: 11.4 years)
Solar Savings Formula
Daily Generation (kWh) = System kWp × Peak Sun Hours × 0.80 (efficiency)
Monthly Savings = Daily kWh × Self-Consumption Rate × Tariff × 30
Payback Period = System Cost ÷ Annual Savings (with compound tariff increases)
Example: 5 kWp System in Johannesburg
5 kWp system — 5.5 hrs/day — R2.80/kWh — R18,000/kWp
Total system cost: 5 × R18,000 = R90,000
Monthly generation: 5 × 5.5 × 0.8 × 30 = 660 kWh/month
Monthly savings (80% self-consumption): 660 × 0.8 × R2.80 = R1,478/month
Payback period (12% tariff increase): ~4.5 years
25-year total savings: R500,000+
Need full precision?
Professional Calculator Complete parameters, sensitivity analysis, and detailed breakdown
Load Analysis — Select Your Appliances
| On? | Appliance | Watts | Hrs/Day | kWh/Day | Priority |
|---|---|---|---|---|---|
| Geyser (3kW) | 6.00 | high | |||
| Fridge (150W) | 3.60 | critical | |||
| Lights (10x10W) | 0.60 | critical | |||
| TV + Decoder | 1.00 | medium | |||
| Laptop | 0.52 | medium | |||
| WiFi Router | 0.36 | critical | |||
| Washing Machine | 2.00 | low | |||
| Microwave | 0.60 | low |
R
Recommended System
4kWp panels + 7kWh battery
Inverter Size
9 kVA
System Cost
R 175 500
Electricity Saving
R 815/mo
Generator Saving
R 4 050/mo
Total Annual Saving
R 58 377
Financing Options
Break-even
3.0 years
20yr Net Benefit
R 4 030 697
Frequently Asked Questions
In 2026, a complete solar + battery system costs R15,000–R25,000 per kWp installed. A typical 5 kWp home system costs R75,000–R125,000 fully installed with batteries and inverter.
With Eskom tariff increases of 12–15% per year, the typical payback period is 4–7 years. After payback, the system generates free electricity for 20+ years.
A typical SA home using 800–1,200 kWh/month needs a 5–8 kWp system (12–20 panels of 400W each). A small flat (400–600 kWh/month) needs a 3–4 kWp system.
Yes — South Africa has some of the world's best solar resources, with most areas receiving 4.5–6.5 peak sun hours/day. The Northern Cape (Karoo) receives the most; the Cape coast slightly less.
Yes. SARS offers a 25% tax rebate on solar panels for private individuals, capped at R15,000 per taxpayer. Businesses can claim accelerated depreciation under Section 12B of the Income Tax Act.