Costs & savings

How do I compare solar export credits vs self-use savings in rand?

Multiply expected export kWh by your metro’s export credit rate, then compare to the retail c/kWh you avoid by self-use — in many metros self-use wins once fixed charges and weak export rates are included.

Updated 27 October 2026 · Illustrative ranges — not a formal quote, credit decision or legal advice.

Answer first: Build a one-page spreadsheet: self-use kWh × retail rate, export kWh × credit rate, minus fixed charges. Prefer the larger rand line — export vs self-use · fixed charges · monthly savings · zero-export · metro tariffs.

Worked comparison skeleton

Self-use rand = kWh avoided × your import c/kWh.
Export rand = kWh exported × published credit.
Net = those lines − fixed charges − expected maintenance.

export caps · net billing · bill still high.

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.

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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

Cape Town 2026/27 worked rand example

On City of Cape Town Home User SSEG (Budget 2026/27 Annexure 6), residential feed-in is 107.98 c/kWh excl. (124.18 c incl.) plus a 25.00 c excl. (28.75 c incl.) SSEG incentive — about 152.93 c/kWh incl. when both apply. Import on the same Home User tariff is far higher once you sit in the upper blocks, and the City still bills the fixed Home User services/wires charge (about R424.30/month) plus AMI where fitted (~R6.80). So if you export 200 kWh and self-use 400 kWh in a month, export credits land around ~R306 while self-use savings against a ~R3+/kWh avoided block can be several times larger — always paste your own bill rates. Sources: Cape Town Ann06 PDF · metro tariffs · CPT net billing · fixed charges.

Export vs self-use decision tree

Write import c/kWh from the last three bills (peak/standard/off-peak if TOU).
Write published export credit from the live metro SSEG PDF — not a WhatsApp forward.
Estimate self-use share with daytime loads (geyser, pool, EV daytime soak) vs pure export.
Subtract fixed charges that do not disappear after panels go up.
Re-run with a zero-export sensitivity if SSEG is delayed — zero-export · export vs self-use.

Desk close on export vs self-use rands

Print your last bill, highlight import c/kWh and fixed charges, then write the live export credit beside them. If self-use wins by a wide margin, prioritise daytime loads and battery soak before chasing SSEG export paperwork — export vs self-use · CPT fixed charges · get quotes.

Quick questions

Where is the export rate?

Live metro SSEG / tariff PDF — not a WhatsApp forward.

Do fixed charges change?

Often unchanged — model them explicitly.

TOU metros?

Shift loads into cheap/PV windows before chasing export.

Zero-export?

Then self-use is the only lever.