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.
Desk close
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — metro tariffs · tariffs 2026 · choose installer · get quotes · check a quote.
Sources homeowners can open
- Your metro SSEG / tariff PDF (live municipal site).
- OEM inverter and battery installation + warranty PDFs for the quoted SKUs.
- NERSA and municipal tariff schedules for the current year.
- Published network price posts (e.g. DriveElectric) when comparing public DC vs home AC.
Commissioning evidence pack
Serial photos, firmware version, export-limit screenshot, CT polarity photo, dual-supply labels, CoC number, guest monitoring login — with the invoice PDF — CoC · export limit · CT clamps · labels · firmware · warranty claims.
Tariff and fixed-charge reminder
Fixed charges remain after panels go up. Model self-use against your metro’s published rates before celebrating a payback slide — fixed charges · monthly savings · export vs self-use · tariffs 2026 · bill still high · metro tariffs · costs & savings.
Safety do-not list
- Do not DIY dual-supply boards, earthing, or MC4 strings.
- Do not bridge RCDs or defeat BMS protections.
- Do not ignore isolation or earth-fault alarms.
- Do not disable export limits or grid-interface settings.
DIY risks · earth leakage · MC4 · DC isolation · red flags · N-E island.
Stage-weekend reality check
Essentials first through your worst Stage window — essentials · Stage strategy · Stage 4 · SoC · Stage table · load shedding hub.
Extra SA context
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — choose installer · get quotes · check a quote · FAQ · about · batteries.
Handover note 1
Photograph serials, labels and the essential board before the cover closes. Keep guest monitoring access with the invoice. Revisit SoC floors when Stage calendars change — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about · costs & savings · batteries.
Handover note 2
Photograph serials, labels and the essential board before the cover closes. Keep guest monitoring access with the invoice. Revisit SoC floors when Stage calendars change — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about · costs & savings · batteries.
Handover note 3
Photograph serials, labels and the essential board before the cover closes. Keep guest monitoring access with the invoice. Revisit SoC floors when Stage calendars change — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about · costs & savings · batteries.
Handover note 4
Photograph serials, labels and the essential board before the cover closes. Keep guest monitoring access with the invoice. Revisit SoC floors when Stage calendars change — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about · costs & savings · batteries.
Handover note 5
Photograph serials, labels and the essential board before the cover closes. Keep guest monitoring access with the invoice. Revisit SoC floors when Stage calendars change — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about · costs & savings · batteries.
Handover note 6
Photograph serials, labels and the essential board before the cover closes. Keep guest monitoring access with the invoice. Revisit SoC floors when Stage calendars change — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about · costs & savings · batteries.
Handover note 7
Photograph serials, labels and the essential board before the cover closes. Keep guest monitoring access with the invoice. Revisit SoC floors when Stage calendars change — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about · costs & savings · batteries.
Handover note 8
Photograph serials, labels and the essential board before the cover closes. Keep guest monitoring access with the invoice. Revisit SoC floors when Stage calendars change — SoC · Stage strategy · Stage 4 · essentials · monitoring · choose installer · get quotes · check a quote · FAQ · about · costs & savings · batteries.
Extra SA context note 2
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — SoC · monthly savings · fixed charges · export vs self-use · choose installer · get quotes · check a quote · FAQ · about · costs & savings · metro tariffs.
Extra SA context note 2
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — SoC · monthly savings · fixed charges · export vs self-use · choose installer · get quotes · check a quote · FAQ · about · costs & savings · metro tariffs.
Extra SA context note 2
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — SoC · monthly savings · fixed charges · export vs self-use · choose installer · get quotes · check a quote · FAQ · about · costs & savings · metro tariffs.
Extra SA context note 2
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — SoC · monthly savings · fixed charges · export vs self-use · choose installer · get quotes · check a quote · FAQ · about · costs & savings · metro tariffs.
Extra SA context note 2
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — SoC · monthly savings · fixed charges · export vs self-use · choose installer · get quotes · check a quote · FAQ · about · costs & savings · metro tariffs.
Extra SA context note 2
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — SoC · monthly savings · fixed charges · export vs self-use · choose installer · get quotes · check a quote · FAQ · about · costs & savings · metro tariffs.
Extra SA context note 2
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — SoC · monthly savings · fixed charges · export vs self-use · choose installer · get quotes · check a quote · FAQ · about · costs & savings · metro tariffs.
Extra SA context note 2
Keep metro and OEM PDFs beside this page. When rand bands disagree with a live primary, the primary wins — SoC · monthly savings · fixed charges · export vs self-use · choose installer · get quotes · check a quote · FAQ · about · costs & savings · metro tariffs.
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.
Desk close on heat pump vs PV order
Get two heat-pump quotes and two PV quotes with the same year’s bills attached. Pick the first project with the faster verified rand saving, then stack the second — water heating · install order.
Quick questions
Heat pump first?
Often when geyser is the top load and roof space is tight.
PV first?
When daytime loads already exist and export/self-use maths work.
Both?
Common — sequence matters for inverter headroom.
Gas geyser?
Different maths — see LPG desk.