Costs & savings
Should I buy a heat pump before more solar PV in South Africa?
If geyser kWh dominates your bill, a heat pump can cut that load at a lower capex than another string of panels — then size PV to the new daytime profile. Run both paybacks in rand, not in brochure kWh.
Updated 27 October 2026 · Illustrative ranges — not a formal quote, credit decision or legal advice.
Answer first: Rank loads by kWh and R/month. If the geyser wins, price a heat pump against another 2–4 panels and pick the better rand return — heat pump vs thermal · add heat pump to solar · smart geyser · geyser on backup · costs & savings.
Decision table
| Signal | Lean toward |
|---|---|
| Geyser >30% of kWh | Heat pump first |
| Large daytime laundry/AC already | More PV / battery |
| Tight inverter headroom | Efficiency kit before more load |
| Weak export credit | Self-use efficiency + PV |
export vs self-use · size system · install order.
Heat pump vs PV — order-of-spend for SA bills
A quality heat pump often cuts geyser kWh by roughly 50–70% for a lower capex than a full hybrid PV+battery set. PV then attacks the remaining daytime loads and TOU peaks. Many Cape and Joburg homes get a faster first-rand saving by fixing the geyser first, then sizing PV against the new lower baseload — not the old resistive geyser profile. Confirm COP claims at your winter inlet temperatures; Highveld winter nights punish optimistic brochure COPs.
- Log 7 days of geyser kWh before shopping.
- Ask for installed Incl. VAT for heat pump + plumbing vs PV-only vs hybrid.
- If an EV is coming, plan the DB and NMD once — install order · LPG geyser · geyser on backup.
Combined payback sketch
Example shape only: a R25k–R45k heat pump saving roughly R400–R900/month of geyser electricity at metro rates can pay back faster than waiting for a R150k+ hybrid to displace the same kWh. Then PV self-use compounds. Always use your tariff — water heating · costs & savings · monthly savings.