Can I run a pool pump on solar in South Africa?

Tariff maths for a daily filter cycle

A 1.1 kW pump running six hours uses ~6.6 kWh/day. At ~400 c retail that is about R26/day (~R800/month) if those hours were grid-imported. Move the same six hours under PV and you attack that line directly; export credits at ~150 c would only have paid ~R10 for the same energy. Timers and pool-cover discipline beat buying a bigger battery to run the pump at night — metro tariffs · self-consume vs export.

Sizing the hybrid day

Add pump watts to daytime coincidence with geyser boost, laundry and EV. A 5 kW hybrid usually copes if loads are staggered; stacking pump + 3 kW element + kettle is how midday trips happen even with fat roofs. Variable-speed / VS pumps cut average watts and soft-start — ask the pool tech for running amps, not only motor kW labels.

Backup-board policy

Filtration can wait a Stage slot; fridge and ONT cannot. Default: pool pump on non-essential/main. Exceptions: algae-prone midsummer with long multi-day outages and a large hybrid explicitly designed for it. Do not discover the pump is on essentials during the first Stage 4 evening — backup sizing · essentials vs non-essentials.

Automation patterns that work

• Simple timeclock in the best PV window (often late morning to mid-afternoon).
• Smart relay tied to inverter surplus / SoC rules where supported.
• Shorter, sun-aligned cycles with a cover instead of 12-hour grid marathon runs.

Owner checklist (print this)

• Measure or read running watts of the pump.
• Move filtration into sun hours before upsizing batteries.
• Confirm the circuit is off the lean backup board.
• Re-check after tariff or SSEG changes.

Heat pumps, chlorinators and coincidence

Pool heat pumps can dwarf filtration loads. Putting both on sun hours without staggering still trips hybrids. Salt chlorinators and robots add smaller but real draws — map them. Cover + shorter filter cycles often beat raw kWh. If the estate mandates multi-hour filtration for shared aesthetics rules, bring that constraint to the designer early.

Worked month sketch

1.1 kW × 5 sun-aligned hours × 30 days ≈ 165 kWh/month. At 400 c that is ~R660/month of potential avoided import if PV covers it — before counting chemical savings from better daytime turnover. That alone can justify timer discipline even on a modest 5 kWp roof.

Rand table — filtration as a self-use appliance

Pick your pump’s running watts from the nameplate or a plug meter — labels lie less than brochures. Examples at ~400 c retail import:

• 0.75 kW × 6 h = 4.5 kWh/day → ~R18/day (~R540/month) if grid-imported.
• 1.1 kW × 6 h = 6.6 kWh/day → ~R26/day (~R800/month).
• 1.5 kW × 8 h = 12 kWh/day → ~R48/day (~R1 440/month) — common when clocks are left on “always.”

Move those hours under PV and you attack retail rates; the same energy exported at ~108–185 c credit is worth a fraction. Cape Town Home User upper-block imports near 469 c make the gap even louder. Fixed services/wires (~R424/month on that tariff) still print either way — pool timers do not delete them — metro tariffs · fixed charges · self-consume vs export.

VS pumps, covers and chemistry

Variable-speed pumps often settle at a few hundred watts for turnover instead of slamming a full-speed induction motor all day. That frees hybrid headroom for geyser or EV in the same sun window. A liquid-solar cover cuts heat loss and debris, so you can shorten filter cycles without inviting algae. Salt chlorinators and robot cleaners add smaller draws — schedule them inside the PV window too. None of this replaces a pool tech’s water chemistry advice; it stops the electricity bill from subsidising a 1970s clock.

Coincidence with geyser, laundry and EV

A 5 kW hybrid that is “fine” with the pump alone still trips when a 3 kW element, a dishwasher heater and the pump overlap. Stagger: pump 10:00–15:00, geyser boost 11:00–13:00 or via diverter, laundry after 13:00, EV when the car is actually home. Write the stagger on the fridge. Whole-home heat-pump pool heaters are a different animal — treat them like aircon on the load study — geyser strategy · dishwasher & laundry · aircon on battery.

Stage policy — default off essentials

Green water after one missed slot is annoying; dark fridges and dead ONTs are expensive. Default the pool circuit to non-essential/main. If midsummer multi-day outages and algae risk force an exception, the quote must show continuous kW, surge and usable kWh with the pump running — not a verbal “it should be fine.” Estate rules that mandate long filtration belong in the design brief on day one — essentials vs non-essentials · backup sizing · runtime tool.

Commissioning tests worth insisting on

• Pump running watts logged with a meter.
• Timer / smart relay demonstrated in the app or at the DB.
• Loaded midday test: pump + planned sun loads without inverter fault.
• Stage simulation: confirm pump drops when essentials island (unless designed on).
• Family one-pager: what to switch if algae risk rises during long Stages.

Paper trail pairs with reading a quote and CoC.

Worked summer week (illustrative)

1.1 kW VS average 0.6 kW for 5 sun hours + 1 h boost = ~3.6 kWh/day under PV. At 400 c that is ~R14/day avoided (~R100/week) versus night-time full-speed 1.1 kW × 6 h grid import at ~R26/day. Over a 90-day heat stretch the difference approaches a few thousand rand — before counting export you avoided wasting. That cashflow often beats buying another 5 kWh of lithium “so the pump can run at 21:00.”

Owner checklist — pool + solar

• Running watts measured, not guessed.
• Filtration clock moved into peak sun before any battery upsize.
• Pump off lean Stage board unless explicitly sized.
• Heat pump / chlorinator / robot mapped on the same diagram.
• Re-check after tariff, SSEG or estate rule changes.

Estates, shared pumps and body corporates

Sectional-title or HOA pools sometimes mandate filtration windows that ignore your roof. Bring the rule into the design brief; you may need a larger daytime PV budget or a VS pump to stay inside hybrid headroom. Shared plant rooms are not DIY contactor jobs — ask the trustees who owns the DB change — sectional title.

Quick questions

Will solar run my pool during load shedding?

Only if the pump is on a backed-up circuit and the hybrid/battery were sized for it. Most lean Stage boards leave the pump off.

Is a VS pump worth it with solar?

Often yes — lower average watts mean more of the filter cycle fits under PV without chasing inverter headroom.

Sources

• Solar News 24 — metro tariffs
• Solar News 24 — load shedding backup
• Solar News 24 — self-consume vs export