South Africa Solar Calculator
Eliminate your Eskom bill and power through load shedding. Enter your monthly bill and city — get your system size instantly.
How to Use This Calculator
Enter your Eskom bill
Start with your monthly electricity bill in Rand and your electricity rate per kWh. Your bill should show your tariff (e.g. Homelight 1, Homelight 2, or your municipality's equivalent). Typical Eskom residential rates in 2026 range from R2.20 to R3.00/kWh. Municipality tariffs vary and are often higher than Eskom's direct supply rates.
Select your city
South Africa is one of the world's sunniest countries. Even Durban (the lowest on this list at 5.2 peak sun hours) receives more sun than most European countries. Upington in the Northern Cape gets 7.0 PSH — among the highest solar irradiance anywhere on Earth. Select your nearest city to get accurate sizing.
Include battery for load shedding
Check the battery option to include battery backup for load shedding. A 10 kWh battery covers most homes through a Stage 4-6 load shedding slot (4-6 hours of outage). For Stage 6 load shedding (up to 12 hours/day), consider 20+ kWh of storage or a generator hybrid system.
The Formula
The 80% system efficiency figure is conservative for South African conditions — shading, dust, temperature, and inverter losses typically reduce output to 75-85% of theoretical. Regular panel cleaning is important in dusty inland areas like Gauteng.
Example
The Nkosi family — Johannesburg, Gauteng
The Nkosi family pays R1,800/month for electricity at R2.50/kWh. They want solar to eliminate most of their Eskom bill and add backup for load shedding. They're in Johannesburg (5.5 PSH) and choose 450W panels with a 10 kWh battery.
Result
With Eskom tariff increases averaging 12-18% per year historically, the Nkosi family's actual payback could be significantly shorter — perhaps 5-6 years. After payback, the 25-year system generates the equivalent of R500,000+ in free electricity (at projected escalated rates). The battery also eliminates the disruption and hidden costs of load shedding.
Solar in South Africa: Key Facts
The load shedding context
South Africa's persistent Eskom load shedding has made solar + battery the most compelling home investment in the country. Stage 4 load shedding (4-6 hours/day) costs the average household and business significantly more than it appears — through food spoilage, generator fuel, lost productivity, and damaged electronics. A solar + battery system typically pays back 30-50% faster in South Africa than a similar investment in Europe or the US, even before accounting for Eskom's aggressive annual tariff increases.
Tax incentives
The South African government introduced a solar panel tax rebate of 25% on the cost of solar panels (not inverter or battery) in the 2023/24 tax year, capped at R15,000. This was a one-year incentive. For 2026, confirm with SARS if any residential solar tax incentives are still in effect. The Section 12B business accelerated depreciation allowance remains in place for commercial solar.
Net metering (small-scale embedded generation)
Some municipalities in South Africa allow net metering or wheeling under SSEG (Small Scale Embedded Generation) tariffs. Cape Town, Ethekwini, and Tshwane have the most developed programmes. Municipalities pay ~R0.50–R1.80/kWh for exported solar. Check with your municipality before sizing your system for export — many require prior approval for grid connection.
Peak sun hours by location
- Upington (Northern Cape): 7.0 PSH — among the best solar resources in the world
- Bloemfontein: 6.0 PSH — excellent
- Cape Town: 5.8 PSH — excellent, but winter is noticeably lower
- Pretoria: 5.7 PSH — excellent
- Johannesburg: 5.5 PSH — excellent; afternoon thunder common in summer
- Durban: 5.2 PSH — good, more cloud and rain than inland cities