How to Save Electricity Costs Charging Your EV in Cape Town | EVCI.tech
I’m Frankie, a licensed electrician and owner of EVCI.tech. I install EV charging points for homes and businesses across Cape Town — that’s my sole focus. These posts share ideas and e‑mobility insights I find interesting. If you prefer it on video — here’s the link
Cape Town EV Owners
Save money charging your EV
Cape Town’s outdated tariff structure means timing and planning matter more than ever. Here’s exactly how to cut your EV charging bill — with real numbers.
R3.40
per kWh if you stay under 600 kWh/month
R4.40
per kWh once you cross the 600 kWh threshold
R250+
potential monthly savings from smart planning
Start here
Look at your whole household first
Before you even plug in your new charger, it’s worth understanding where your existing electricity is going. Adding an EV to your home is a significant new load — and the easiest way to make room for it in your budget is to find savings elsewhere first.
In a typical South African household, the single biggest consumer of electricity isn’t lighting, appliances, or entertainment — it’s your geyser.
Geyser — 40%
Everything else — 60%
Water heatingLights, plugs, appliances, etc.
A standard 3 kW, 150 litre geyser runs for roughly 2–3 hours a day to keep up with household hot water demand. That works out to approximately 225–270 kWh per month — one of the largest single line items on your bill.
What your geyser actually costs
250 kWh
average monthly geyser use
×
R3.50
per kWh
R875
spent every month just heating water — before you even charge your EV
The real comparison
Your EV is now your biggest appliance
A standard 7 kW home wallbox — the type usually supplied by your EV dealership — draws more than double the power of your geyser element. Charging typically takes 4 to 8 hours per session, depending on your battery size and how depleted it is.
Assuming 20 charging days a month at an average of 6 hours per session, here’s what that adds up to:
Monthly EV charging cost
20
charge days/month
×
6 hrs
average per charge
×
7 kW
charger output
840 kWh
drawn per month — at a blended rate this costs roughly R2,850–R3,700 depending on which tariff block you fall into
Based on a 7 kW charger running 6 hours/day, 20 days/month. Actual hours depend on daily distance driven and battery size.
Geyser
250 kWh
≈ R875/mo
Hot water for the whole household, every day of the month.
VS
EV charging
840 kWh
≈ R2,850+/mo
More than 3× your geyser’s draw, at full daily charging.
Your EV has become over 3 times more energy-hungry than your geyser — the appliance most households assume is their biggest electricity cost. This is the real number to plan around.
💡
A smaller charger won’t save you money
It’s tempting to think a smaller 3.6 kW wallbox will reduce your bill. It won’t. You pay for kWh consumed, not kW of charger power. A smaller charger simply takes longer to deliver the same energy — same cost, slower result.
Power Usage Snapshot
What’s actually eating your bill
Typical monthly cost per appliance, highest to lowest
🚗
EV charger (7kW wallbox)
R1,528/mo
🚿
Geyser (150L)
R1,400/mo
🌡️
Pool heat pump
R520/mo
❄️
AC unit — lounge
R400/mo
🔌
Inverter battery charging
R360/mo
🍞
Oven
R240/mo
🏊
Pool pump (filtration)
R220/mo
❄️
AC unit — bedroom
R200/mo
🧊
Fridge / freezer
R180/mo
🔥
Stove hob
R180/mo
☕
Kettle
R48/mo
🍟
Air fryer
R32/mo
💡
Security lights (LED)
R20/mo
🍞
Toaster
R12/mo
ⓘEV charging based on 2,000 km/month at the South African average of 19.1 kWh per 100km — works out to roughly 380 kWh/month on a home 7kW wallbox.
Estimated total — all appliances + EV
R5,340/month
At R4.00/kWh across 14 typical household loads
The hidden stuff nobody thinks about
Standby power (TVs, chargers, routers)
~15–25 kWh/month, just sitting idle
Geyser thermostat losses
Heat lost through poor insulation, even when unused
Pool pump oversizing
Most pumps run far longer than the pool actually needs
Inverter idle draw
Draws power 24/7, even with nothing connected
Old fridge door seals
A worn seal can double the fridge’s running cost
WiFi router and modem
Small draw, but running every hour of every day
Estimates based on typical South African household appliance wattages and usage patterns. Actual cost varies by appliance size, age, efficiency rating, and habits.
The tariff problem
Cape Town has no off-peak rate
In most countries with high EV adoption, utilities offer time-of-use (TOU) tariffs — cheaper electricity overnight to encourage off-peak charging. Cape Town, unfortunately, does not offer this to ordinary residential customers – – Source
Instead, the City charges a flat block tariff — the more you use in a month, the more each unit costs, regardless of what time of day you draw it. TOU pricing exists only for certain commercial and industrial accounts, not for homes.
✓ Block 1
R3.40
0 – 600 kWh/month
The lower rate. Applies to all usage until you cross 600 kWh in a calendar month.
✗ Block 2
R4.40
600+ kWh/month
Once you cross the threshold, every additional unit — for the rest of the month — costs more.
This means an EV owner who charges freely without planning can easily push their entire household into the expensive Block 2 rate — making every kWh in the home more costly, not just the EV’s share.
The strategy
Stay under the 600 kWh line
The smart move to save money charging your EV is to budget your monthly usage so your household stays in Block 1. A reasonable split for most homes:
House — 300 kWh
EV — 300 kWh
0 kWh600 kWh cap
On a 60 kWh battery, 300 kWh of charging budget gives you roughly 5 full charges a month — translating to about 1,500–1,600 km of driving, or roughly 400–500 km a week.
For most commuters, that’s comfortably enough. With a bit of planning — charging to 80% rather than 100%, and being mindful in high-mileage weeks — staying under the 600 kWh threshold is realistic for the majority of Cape Town households.
Still cheaper than petrol — by a wide margin
1,600 km a month in an average petrol car (around 7 L/100km) at current coastal pump prices (~R26/litre) costs roughly R2,900 in fuel.
The same distance in an EV, charged within Block 1 at R3.40/kWh, costs roughly R1,000–R1,050 in electricity.
Even if you occasionally spill into the more expensive Block 2 rate, an EV remains significantly cheaper to run than a comparable petrol vehicle either way.
The action plan
Three practical ways to save
None of these require expensive upgrades. They’re habits and small investments that compound every single month.
1
Charge to 80%, not 100%
Set your onboard charge limit to 80% for daily use. This is the single biggest lever you have — it directly reduces your monthly kWh draw and helps you stay inside the cheaper Block 1 tariff.
2
Install a geyser management unit
A geyser timer or smart control unit can cut water-heating consumption by roughly 30% — around R200–R300 a month — freeing up headroom in your 600 kWh budget for EV charging, and reducing strain on your DB when both loads run together.
3
Buy the smallest battery for your longest typical drive
A bigger battery means more kWh to replace every charge. Choosing an EV sized to your real-world driving needs — not your longest annual road trip — keeps your monthly charging budget lower year-round.
⚠️
A note on tariff fairness
Cape Town’s lack of a residential time-of-use tariff means EV owners currently get no reward for charging overnight versus during peak hours — unlike many cities internationally. Until that changes, staying under the Block 1 threshold is the only lever available to manage your rate.
Hi – this is a test comment. The email address and/or URL is not required