Costs
How much does solar save per month in South Africa?
Most suburban South African hybrids that displace 300–500 kWh/month of grid use save roughly R1 000–R2 200/month on energy charges at 2026/27 metro rates — before counting fixed charges that solar does not remove. Empty-house daytime use lands lower; heat-pump and EV self-use land higher. Export credits add a little, not a lottery win.
Updated 27 October 2026
Monthly savings equal the kWh you stop buying times the rate those kWh would have cost, minus any new fixed charges your SSEG tariff adds. That is why two homes with identical 6 kWp arrays can see wildly different rand results on the same street.
Quick ranges (illustrative, 2026/27)
| Self-used PV displaced | Blended avoid rate | Approx. monthly energy saving |
|---|---|---|
| 200 kWh | 320 c/kWh | ~R640 |
| 350 kWh | 380 c/kWh | ~R1 330 |
| 450 kWh | 420 c/kWh | ~R1 890 |
| 600 kWh | 450 c/kWh | ~R2 700 |
Cape Town Home User high-block energy is about 469 c/kWh incl. VAT above 600 kWh — cutting the top of the bill pays fastest. City Power prepaid high blocks sit roughly mid-300s to mid-400s c/kWh. Always use your schedule: metro tariffs · tariffs answer.
Fixed charges still arrive
Cape Town Home User services + wires is about R424.30/month. Tshwane SSEG structures can add about R324 excl./month class fixed. eThekwini bills network access per kVA of inverter. Eskom Homeflex has its own daily fixed (Homeflex 1 about R23.02/day in the 2026/27 booklet path). If your savings story forgets these, the bank statement will feel disappointing — bill still high? · Homeflex export.
Self-use beats export — every time
2026/27 export credits sit near 152.93 c (Cape Town), 143.29 c (City Power), 108.25 c (Tshwane) and 184.60 c (eThekwini) incl. VAT on the paths we tabulated. That is often only a third to half of what you pay to buy a kWh. Designing for maximum export is how systems look busy on a portal and soft on a statement. Put heat pumps, laundry, dishwashers and EV charging into sun hours first.
How to raise monthly savings without buying more panels
- Move geyser / heat pump into sun hours — heat pump vs solar geyser.
- Charge the EV on surplus or off-peak — not peak TOU — TOU EV.
- Stop lazy daily grid-charge-to-100% settings — grid-charge guide.
- Fix shade and dirty panels before upsizing — cleaning.
- Confirm you are on the intended post-SSEG tariff, not a punitive leftover class.
Worked Cape Town sketch
Home uses 750 kWh/month. After solar, grid imports fall to 350 kWh and you export 80 kWh. Energy saved is about 400 kWh times ~400 c blended — about R1 600. Export credit is about 80 times 1.5293 — about R122. Fixed charges unchanged. Net about R1 700/month against a R100k system means simple payback near five years. Change self-use to 250 kWh and the monthly saving falls near R1 000 — which is why daytime presence and timers matter more than brochure peak watts. Full method: payback · payback by metro · 5 kW cost.
EV and heat-pump multipliers
A heat pump that shifts water heating into midday can add meaningful self-use. An EV that draws 200 kWh/month from home at about R3.50–R4.70/kWh versus public DC near R7+ (DriveElectric examples; SAEV Richmond cited about R3.49/kWh DC on a battery-backed site) changes both the petrol budget and the solar story — cost to charge · whole-home order · EV pillar.
Seasonality
June–August Highveld and Cape winter roofs produce less. Monthly savings swing with yield and with geyser use. Judge the system on a rolling 12 months, not one grey week. Cloudy-day expectations: cloudy production.
What installers sometimes inflate
- Assuming 100% self-consumption on a weekday-empty house.
- Valuing export at retail buy rates.
- Ignoring prepaid-to-TOU migration fees or meter swaps.
- Counting Stage 6 “lifestyle value” as if it were cash on the bill.
- Hiding fixed charges when presenting “your new bill.”
How to track your own number
- Screenshot the pre-solar bill (kWh + rand + tariff name).
- After commissioning, export monthly portal production, self-consumption and import.
- Multiply displaced kWh by the block rates you actually avoided.
- Subtract any new SSEG fixed charges.
- Review settings if savings stall — fault codes, grid-charge, clipping.
Three ledgers, not one “solar saves” number
Healthy household tracking splits:
- Displaced import kWh × block rates avoided — the real engine.
- Export credits — usually 24–52% of the buy rate on 2026/27 metro tables we track; never the hero.
- New fixed / SSEG / AMI lines — subtract these every month or you will overstate wins.
Example shape (illustrative Cape Town Home User): 450 kWh self-used avoiding a blended ~380 c → ~R1 710 energy saving; 80 kWh exported at 152.93 c → ~R122 credit; fixed services/wires ~R424 still due. Net “solar effect” ≈ R1 408 before loan debits. Change the self-use fraction and the story changes more than changing module brand.
When a battery raises monthly savings — and when it does not
Batteries earn their keep when they (a) catch daytime surplus that would have exported cheaply and (b) cover evening peak imports or Stage slots you care about. On flat prepaid tariffs with weak export credits, a timer on the geyser/pool can beat a small battery on pure rand/month. On Cape Town-style TOU experiments or high evening peaks, shift value rises — model it — Cape TOU · battery guide.
Joburg / Tshwane / eThekwini sketches (same method)
Reuse the three-ledger method on local buy rates from the metro tariffs desk:
- City Power prepaid high blocks (~334–437 c): 400 kWh self-use ≈ R1 340–R1 750 energy saving before fixed lines; export only if you have completed the TOU conventional migration.
- Tshwane inclining blocks (~324–446 c): similar energy maths, but subtract the SSEG fixed (~R324/month excl. class on published notes) before celebrating.
- eThekwini domestic (~357 c class): strong export credit (~185 c) still loses to self-use; watch kVA access on inverter size.
Always replace these sketches with your bill’s tariff code. Installer “up to R3 000/month” claims that ignore fixed charges and winter yield are marketing, not maths — fixed charges · payback.
Fixed charges that survive solar
Service / capacity / AMI fees and (in eThekwini) network-access on inverter kVA stay on the bill after SSEG. A quote that shows “R0 municipal bill” after solar is incomplete — model energy savings only, then subtract the floor you will still pay. Detail: fixed charges · bill still high.
Export is a thin slice
FY2026/27 residential export credits (incl. VAT guide): Cape Town base+incentive ≈152.93 c, City Power ≈143.29 c, eThekwini ≈184.60 c; Tshwane NERSA RfD ≈108 c with a City FAQ caveat to confirm live. Import blocks are often 2–3× higher — every kWh used at home beats an exported kWh on payback — feed-in · City Power SSEG.
Seasonality and the 12-month file
July production is not October production. Average the last 12 municipal bills, then stress-test savings at 70% and 100% of modelled PV yield. If payback only works at the sunny case, keep cash reserves or shrink the finance term — winter production · payback · cloudy days.
Quick questions
Why did my neighbour save more?
Different tariff blocks, different daytime presence, different battery grid-charge settings, or a bigger array aimed at self-use.
Will savings rise every year?
Tariffs usually rise each July/April; that improves the value of each self-used kWh if your system stays healthy. Hardware also ages — clean panels and watch inverter faults.
Is R2 000/month realistic?
Yes if you displace about 400–500 high-block kWh on Cape Town-like rates and use most PV yourself. Not typical for a tiny 3 kWp grid-tie with nobody home.
Where this sits on the Solar News 24 desk
Read next: home solar pillar, costs & savings, metro tariffs 2026/27, and how to size a system. For EV households, pair with the EV charging guide (DriveElectric / SAEV cost cites). Always verify figures on your own bill and distributor schedule — municipal tariffs change every July.