Tariffs
Should I opt into Cape Town’s Residential Time-of-Use tariff with solar and a battery?
Only if you have (or will install) AMI metering, can shift or battery-shift load out of peak windows, and have modelled the new administration + capacity fixed charges against your self-use savings. On the City’s 2026/27 annexure, high-demand peak energy sits near an 898 c/kWh incl.-VAT class rate while off-peak is far cheaper — batteries that discharge through peak and refill from PV can win, but fixed TOU charges do not disappear. Opt-in; do not assume Home User automatically converts.
Updated 27 October 2026 · Illustrative ranges — not a formal quote or legal advice.
What the City published for 2026/27
Cape Town introduced an opt-in Residential Time-of-Use tariff for customers with AMI metering. Annexure figures (excl. VAT in the budget notes; add 15% for incl.-VAT household maths) include an administration charge and a capacity charge alongside peak / standard / off-peak energy for high-demand (June–August) and low-demand seasons. High-demand peak energy is in a different league from Home User’s inclining blocks — the City’s own explanatory notes frame the product as enabling battery arbitrage similar in spirit to Steenbras. Always open the live Budget Annexure 4 / Annexure 6 PDFs before you sign anything — metro tariffs.
Home User vs Residential TOU — sticky charges still win arguments
Home User still carries Services and Wires near R424.30/month incl. VAT with block energy ~356 c then ~469 c. Residential TOU replaces that shape with administration + capacity charges (hundreds of rand per month combined on the published schedule) plus TOU energy. Neither tariff deletes fixed costs when you add solar. Export credits on the standard Home User SSEG path (~153 c class incl. VAT) remain thin versus peak imports. Model both tariffs with your real half-hourly shape if you have AMI data — fixed charges · feed-in.
When solar + battery makes TOU rational
- You can discharge through morning/evening peaks and recharge from PV (or cheap off-peak) without starving Stage reserves.
- Flexible loads (geyser, pool, EV, laundry) already sit in sun or off-peak windows.
- Your installer can show a spreadsheet with your kWh by TOU bin, not a brochure average.
- AMI costs and lead times are explicit on the quote.
If your household is night-heavy, peak-aligned cooking and heater use with no battery, TOU can hurt. Self-use discipline still leads on either tariff — export vs self-consume · do I need a battery?.
Stage reserves vs arbitrage
Do not empty the pack into peak shaving if a multi-slot evening is forecast. Good hybrids let you set a minimum SoC for backup and a separate window for tariff discharge. Write those setpoints into the commissioning pack. Grey winter Highveld/Cape mornings cut PV refill — hold more reserve in June–August when high-demand peaks also bite — grid-charge before shedding · load shedding · cloudy production.
Worked sketch (illustrative, not advice)
Suppose you shift 8 kWh/day out of high-demand peak into PV-charged battery discharge. If the peak-vs-off-peak gap were even 400 c, that is ~R32/day in energy structure (~R960/month) before fixed TOU charges. If those fixed charges exceed Home User’s wires line by more than your achievable shift, stay on Home User until AMI data proves otherwise. Rebuild the quote both ways.
SSEG, export and paperwork
TOU consumption and SSEG export enablement are related but not identical paperwork trails. Confirm whether feed-in on TOU is available yet — City notes have flagged TOU export rates that only activate once back-end systems are ready. Do not assume export credits on a TOU opt-in until the consent letter says so — SSEG registration · do I need SSEG?.
Owner checklist
- AMI present or quoted with cost and date.
- Side-by-side Home User vs TOU bill using your load shape.
- Battery SoC policy: peak shave vs Stage reserve.
- Flexible loads already on timers before you opt in.
- Export credit assumptions verified on the live consent path.
How to gather AMI evidence before you opt in
If you already have AMI, export a month of interval data and bin it into the City’s peak/standard/off-peak windows for high- and low-demand seasons. If you lack AMI, treat the meter upgrade cost and lead time as part of the TOU decision, not a surprise. Ask the City/installer which TOU bins apply on public holidays and how capacity charges behave if you downsize the breaker later.
Compare three bill rebuilds: (1) stay Home User with today’s solar self-use, (2) TOU with battery peak-shave and PV refill, (3) TOU without behavioural change. Only option 2 should be allowed to win on paper. Keep Stage reserve SoC sacred in June–August when high-demand peaks and grey mornings overlap. Re-read Annexure 4 notes yearly — Council can tweak incentives and structures.
Related reading: 2026/27 tariffs by metro · payback · read a quote · costs & savings.
Installer questions specific to TOU
- Who lodges the AMI / tariff change and which milestone pays for it?
- Can the hybrid automate peak discharge with a hard SoC floor for Stages?
- What happens to SSEG export credits the day TOU activates?
- Will firmware support Cape TOU calendars without manual season toggles?
- Show me the failure case: TOU fixed charges up, peaks not shaved.
If the salesperson cannot answer those five, stay on Home User until someone can. TOU is a sharp tool: excellent with data and batteries, expensive with hope.
Worked cautionary tale
Family opts in, leaves geyser on a 05:00 boost into high-demand peak, charges the EV at 18:30, and keeps the battery at 100% “for load shedding.” Peak imports spike; capacity/admin charges print; export stays thin. They blame solar. The fix is behavioural and settings-level — not another string of panels. Solar News 24’s rule: prove the shift on AMI data for 30 days before you celebrate the tariff change.
Fixed-charge arithmetic you should spreadsheet
Pull the live administration and capacity charges from the City PDF (excl. VAT in many tables — multiply by 1.15 for household incl.-VAT maths). Add them and compare to Home User’s Services and Wires near R424.30 incl. VAT. Your battery-shift savings must clear that fixed delta plus any AMI costs amortised over the year. If the spreadsheet only “works” when you invent perfect peak avoidance every weekday, it does not work.
High-demand peak near the 898 c incl.-VAT class rate is the prize; off-peak near the 300 c class band is the refill lane. Standard bins sit in between. Seasonality matters: June–August peaks are the stress test. Low-demand months still have peaks — do not disable automations in September and forget to re-enable them in June.
Quick questions
Is Residential TOU mandatory with solar in Cape Town?
No. It is an opt-in product that needs AMI. Many solar homes remain on Home User. Model both before you switch.
Can I use TOU without a battery?
Possible if you can move large loads into off-peak/standard windows, but batteries are how most households actually dodge peaks. Without shift, peak rates can hurt.
Sources
TOU + battery: charge rules that matter
Programme grid-charge windows against Cape Town’s published TOU blocks and your SSEG conditions. Blind “charge from grid always” can erase savings; blind “never grid-charge” can leave you empty on a cloudy Stage evening — grid charge · export limits · winter yield.
Export-limit while SSEG is pending in Cape Town
Many homes lawfully run zero-export self-use during the City process. Put that mode on the commissioning sheet so nobody “opens export” early — Cape Town steps · export limits.