Sizing & savings
What size solar system do I need for a R3 000 electricity bill in South Africa?
A R3 000 monthly bill buys about 690–790 kWh in the big metros in 2026/27 — roughly 23–26 kWh a day. The system that pays back fastest on that bill is a 5 kW hybrid inverter, about 5 kWp of panels and 10–16 kWh of usable lithium storage. In Cape Town, offsetting 500 kWh of a 694 kWh month cuts the bill from R3 000 to about R1 115 — a saving near R1 885 a month — because the R424.30 fixed charge stays and the top block disappears first.
Updated 27 October 2026 · Worked examples use published tariffs; not a formal quote, credit decision or financial advice.
Answer first: Start from kWh, not rand. A R3 000 bill is roughly 700–790 kWh a month in the major metros, and solar removes the most expensive kWh first. Size the system to cover the daytime load and charge a battery for the evening, and the bill drops by about R1 800–R1 900 a month. Related: how many panels · inverter size · 5 kW cost.
Turn R3 000 into kWh
| Metro and tariff (2026/27, incl. VAT) | How the R3 000 splits | kWh a month | kWh a day |
|---|---|---|---|
| Cape Town Home User: R424.30 fixed, 355.95 c to 600 kWh, 469.06 c above | R424.30 fixed + R2 135.70 for 600 kWh + R440 for 94 kWh | ≈694 | ≈23 |
| City Power prepaid: 334.03 c to 350 kWh, 383.16 c to 500 kWh, 436.59 c above | R1 169 for 350 kWh + R575 for 150 kWh + R1 256 for 288 kWh | ≈788 | ≈26 |
Sources: City of Cape Town 2026/27 tariff Annexure 6; City of Cape Town cost-of-electricity page; City of Johannesburg 2026/27 electricity tariffs. The arithmetic is ours. If you are on Eskom direct or another municipality, read the kWh line on your bill — Cape Town fixed charges and your bill.
The system that fits
At 23–26 kWh a day, a typical household uses a bit under half in daylight and the rest from late afternoon through the night. The system that matches that pattern:
- Inverter: 5 kW hybrid. It carries the kettle, geyser element on a timer, pool pump and fridge together, and charges a battery while it powers the house.
- Panels: about 5 kWp — nine or ten 550–580 W modules. In most of South Africa that delivers roughly 20–23 kWh on a clear day (sizing a system).
- Battery: 10–16 kWh usable LiFePO₄ on a 48 V DC bus — the oldest, most proven home hybrid architecture. 10 kWh covers a typical evening; around 16 kWh usable is the sweet spot that carries the evening and overnight base load and sets you up for an EV later.
That is the classic 5 kW package that installers quote every day, which keeps prices competitive. Our 5 kW cost desk tracks installed 5 kW hybrids with 5–10 kWh of lithium at roughly R72 000–R120 000 in 2026; a larger battery adds to the top of that range.
What it saves: the Cape Town worked example
Take the 694 kWh Cape Town month and let solar plus battery cover 500 kWh of it:
| Line | Before solar | After solar |
|---|---|---|
| Fixed service and wires charge | R424.30 | R424.30 |
| Block 1 (355.95 c) | 600 kWh = R2 135.70 | 194 kWh = R690.54 |
| Block 2 (469.06 c) | 94 kWh = R440 | 0 |
| Bill | R3 000 | ≈R1 115 |
The saving is about R1 885 a month, or R22 600 a year at today’s tariff. On a City Power prepaid meter, covering 450 kWh of a 788 kWh month leaves 338 kWh in the first block — about R1 129 in tokens — for a saving near R1 870 a month. Every July increase makes the saving bigger; NERSA approved 9.01% for municipal supply in 2026/27 (NERSA media statement (March 2026)).
Payback
A R95 000 system saving R22 600 a year pays back in a little over four years at today’s tariff, and faster as tariffs climb. A R120 000 system with a bigger battery lands near five and a half years at today’s tariff. Both sit well inside a 10-year battery warranty and a 25-year panel warranty, which means the system has years of free savings left after payback. More in payback maths and year one vs year ten.
Why the bill never reaches zero
Fixed charges stay. Cape Town’s Home User service and wires charge is R424.30 a month whether you use 0 or 694 kWh (City of Cape Town cost-of-electricity page). Winter weeks with rain also pull some grid power. Plan for a bill that falls by 55–65%, not to nil — and then put the saved R1 800+ against the system cost. See fixed charges with solar.
Subscriptions on a R3 000 bill
Subscription plans are sold by bill size, so compare the plan with the energy portion it can actually remove:
- Versofy’s bill-based tier for bills up to R3 000 is published at R2 799 a month (EnergyBee Versofy review (retrieved 9 Oct 2026)). Against a R3 000 Cape Town bill with R424.30 of fixed charges, that plan costs more than the R2 576 of energy it could ever replace.
- GoSolr’s large plan, aimed at bills from R3 000, is R1 699 a month plus a once-off admin fee, escalating with CPI each July (GoSolr product page). Against a saving near R1 885 that leaves under R200 a month, before the admin fee.
Owning the system — cash or a short bond draw — keeps the full R1 885 in your pocket. Compare routes in cash vs bond vs rent-to-own.
Five ways to get more from the same system
- Move the geyser into daylight. A timer or smart controller running the element 10:00–15:00 shifts the single biggest load onto the roof — smart geyser timers.
- Run the pool pump, dishwasher and washing machine in sun hours.
- Keep the battery for the evening, not for running the oven at noon.
- Do not oversize for export. Cape Town credits 152.93 c/kWh incl. VAT on export against 355.95–469.06 c on import, so a kWh used at home is worth more than double a kWh exported (export vs self-use).
- Buy batteries on rand per usable kWh and warranted throughput. Solar MD’s SS4160 warranty of 12 years or 84 MWh to at least 60% capacity (Solar MD) is why longevity-focused buyers shortlist it next to other LiFePO₄ brands; compare the full field in batteries.
Get the quotes right
Ask three installers to quote the same spec: 5 kW hybrid, about 5 kWp of panels, usable battery kWh stated in writing, CoC and SSEG registration included. Installers who buy through established wholesalers — ACDC Dynamics, Voltex, ARB, Herholdts, DBS Energy or SONAH Group — keep stock and warranty swaps local (trusted wholesalers). Then read every line with our quote checklist.
Bottom line
A R3 000 bill is about 690–790 kWh a month. A 5 kW hybrid with about 5 kWp of panels and 10–16 kWh of usable storage cuts it by roughly R1 850–R1 900 a month at 2026/27 tariffs and pays back in about four to five and a half years. Own the system if you can; a subscription priced near your bill cannot beat the fixed charges.
Quick questions
How many kWh is a R3 000 electricity bill?
About 694 kWh in Cape Town on the 2026/27 Home User tariff including the R424.30 fixed charge, and about 788 kWh on City Power prepaid blocks. Check the kWh line on your own bill or token slips.
How many solar panels do I need for a R3 000 bill?
About 9–10 panels of 550–580 W, giving roughly 5 kWp, on a 5 kW hybrid inverter. That covers the daytime load and charges a 10–16 kWh battery for the evening.
How much will solar save on a R3 000 bill?
Around R1 800–R1 900 a month when solar covers about 500 kWh of a 700–790 kWh month. Fixed charges stay on the bill, so the bill never drops to zero.
Is a solar subscription worth it on a R3 000 bill?
Only if the subscription costs clearly less than the energy portion it removes. A plan priced near R2 800 cannot pay on a R3 000 bill once fixed charges are counted; a plan near R1 700 leaves a thin margin.