For many South African households and small businesses, solar has shifted from a “nice-to-have” to a very strong financial option. Analyses of Eskom tariffs versus inflation show that electricity prices have increased several times faster than inflation since the 2008 power crisis, with real tariffs rising roughly six-fold between 2007 and 2024. You can see this clearly in PowerOptimal’s long-term tariff vs inflation graphs: “2024 update: Eskom tariff increases vs inflation since 1988” .
At the same time, South Africa has excellent solar conditions. The Department of Mineral Resources and Energy (DMRE) notes that most parts of the country receive more than 2 500 hours of sunshine per year, with average solar radiation in the range of 4.5–6.5 kWh/m² per day – among the best in the world for solar PV.
1. Where are electricity prices now?
Eskom’s approved tariffs are published annually in its Tariffs and Charges section and detailed in the 2025/2026 Tariff Booklet (PDF) . For 2025/26, NERSA granted Eskom an average increase of about 12.7 %, according to reporting on the NERSA decision .
Once you add municipal markups, network charges and VAT, many households end up paying an effective rate in the region of roughly R2.00–R4.50 per kWh, depending on municipality, tariff structure and usage block. That’s why monthly bills of R1 800–R3 000 are now very common for grid-connected suburban homes.
2. What do solar systems really cost in 2025?
Recent South African cost guides put typical residential solar PV system prices in these ballparks:
- Small home systems: around R70 000 for a basic solar PV installation for a smaller home, according to LocalPros’ 2025 solar panel cost guide .
- Larger home systems: up to roughly R350 000 for higher-capacity systems with more panels, larger inverters and batteries, based on the same LocalPros guide.
- Per-panel prices: individual panels for residential use typically cost several thousand rand each. EcoFlow’s South African store, for example, lists rigid 100 W and 400 W panels in the R2 000–R8 000 range depending on wattage and model ( EcoFlow ZA – Solar Panel Price Guide ).
When you package panels, a hybrid inverter, mounting and installation, a realistic installed cost band for residential grid-connected systems in 2025 often ends up around:
- 3–5 kW: roughly R65 000 – R110 000
- 5–8 kW: roughly R110 000 – R180 000
- 8–12 kW: roughly R180 000 – R280 000
These are indicative ranges compiled from multiple installer quotes and cost guides and will vary by brand, battery size, roof complexity and location.
3. How strong is South Africa’s sunlight really?
DMRE’s renewable-energy reports and speeches (for example Minister Mantashe’s 2022 Solar Power Africa address ) consistently highlight that South Africa enjoys more than 2 500 hours of sunshine annually, with solar irradiance commonly in the 4.5–6.5 kWh/m²/day band. This is why even modest-sized systems here can produce substantial energy.
For the calculator, we translate this into conservative “peak sun hours” per province so that your estimate errs on the safe side rather than overselling output.
4. Worked example: a typical R2 500/month home
Let’s mirror what the calculator does in simplified form.
- Monthly bill: R2 500
- Assumed effective tariff: R2.85/kWh (within current residential ranges)
- Estimated monthly usage: R2 500 ÷ R2.85 ≈ 875 kWh
- Coverage target: 80 % of that usage
80 % of 875 kWh/month is about 700 kWh/month, or roughly 23 kWh/day. If we assume a conservative 5 peak sun hours per day:
Using 550 W panels (0.55 kWp each), that’s roughly 9–10 panels. Applying a conservative installed price range of R15 000–R22 000 per kWp puts the system cost between R69 000 and R101 000.
If that system displaces about R2 000 of your monthly bill (because a small portion may still go to fixed charges or grid import), a simple payback looks like:
This ignores financing costs, maintenance and tariff changes, but it shows why many households are seeing paybacks in the 4–6 year range.
5. When does solar usually make sense?
Solar is often worth it if:
- Your monthly bill is consistently above R1 500
- You expect to stay in the property at least 3–5 years
- Your roof has usable north, north-east or north-west exposure with limited shading
- Load-shedding materially affects your income or daily life
Solar might not be worth it (yet) if:
- You rent and can’t transfer the system or recover the cost
- Your roof is badly shaded or structurally unsuitable
- Body corporate or landlord rules prohibit PV or batteries
- Your usage is very low (< R800/month) and you’re already energy efficient
6. Where the SolarSaverZA calculator fits in
The SolarSaverZA calculator turns your inputs into a transparent estimate using:
- Typical South African residential tariffs as a starting point
- Conservative peak-sun-hour assumptions by province (from DMRE and solar maps)
- Realistic residential and small-business cost ranges from public market guides
- A simple savings and payback calculation
It will not replace a formal engineering design, but it should arm you with solid ballpark numbers before you invite installers to quote.
References & data sources
- Department of Mineral Resources and Energy – Solar power overview: dmre.gov.za/…/solar-power
- Minister of Mineral Resources and Energy – Solar Power Africa 2022 address (solar resource figures): gov.za/news/speeches/…
- Eskom – Tariffs and Charges (official tariff documentation hub): eskom.co.za/distribution/tariffs-and-charges
- Eskom – Tariffs and Charges Booklet 2025/2026 (PDF): Tariff-booklet2.pdf
- PowerOptimal – Eskom tariff increases vs inflation since 1988: poweroptimal.com/2024-update-eskom-tariff-increases-…
- Reuters – “Eskom wins approval for tariff increase of 12.7% for 2025/26”: reuters.com/world/africa/…
- LocalPros – “How much do solar panels cost?” (South Africa, 2025): localpros.co.za/cost/how-much-do-solar-panels-cost
- EcoFlow South Africa – Solar panel price discussion: ecoflow.com/za/blog/solar-panel-for-home-price