01
Your switchboard might be the real bottleneck.
Switchboards built more than 25 years ago weren’t designed for an extra continuous 32 A load. The electrician will check three things: capacity (does the main switch and supply have headroom?), spare ways (is there room for the new circuit?), and condition (are old porcelain fuses or asbestos backings going to fail safety inspection?).
Switchboard upgrades range from “a couple of hundred dollars in spare parts” to $1,800–$3,500 to bring the whole thing up to code. An EV charger is one of the largest continuous loads a home will ever have — equivalent to running a big air conditioner non-stop — and old infrastructure can’t always cope.
02
The blown-fuse problem nobody talks about.
Three of my neighbours have switched to electric cars in the last eighteen months. Two of them have caused the LV pole fuse on the local street transformer to blow — the low-voltage fuse on the customer side of the pole transformer, which protects the LV cable run and the transformer winding from sustained overload. When that fuse goes, it doesn’t just affect the EV owner; it takes out everyone fed from the same transformer. Lights out for the whole block until a truck rolls and a sparky climbs the pole.
Each suburban street transformer feeds somewhere between 5 and 30 houses, depending on the area. It was sized decades ago for the loads of that era — lights, fridges, a kettle, eventually some air conditioners. A 7 kW EV charger running 6+ hours overnight is one of the heaviest sustained domestic loads ever invented. One on the street is no problem. Several plugging in on a hot evening with everyone’s air conditioner running — and the transformer goes from “warm” to “thermal limits exceeded” to “LV fuse blown” in fairly short order. Peer-reviewed research published in Sustainable Energy, Grids and Networks (2023) documented that EV-induced transformer overloads typically manifest as exactly this: blown LV fuses, pressure relief activations, or accelerated winding insulation aging.
Worth noting: there’s a second fuse on the pole — the HV drop-out fuse cutout on the high-voltage side of the transformer. That one is sized for short-circuit protection, not overload, and won’t blow from gradual EV-driven loading. It’s the LV fuse on the customer side that responds to too much sustained domestic load.
03
The DNSP now has a remote dial on your charger.
Since December 2024, every new EV charger above 20 A in Australia must support AS 4755 demand response — meaning the Distribution Network Service Provider (DNSP) can send a signal to your charger to slow down or pause during grid stress. In Queensland, Energex enforces this through the Queensland Electricity Connection Manual (QECM). A dedicated EV charger above 20 A — typically 32 A — must have Active Device Management via one of three options:
- Economy / load control tariff (Tariff 33 / Controlled Load 2) — the EV charger is wired to a separate metered circuit that Energex can switch off and on, similar to how off-peak hot water systems have worked for decades. Provides at least 18 hours of supply per day, but timing is at the network’s discretion.
- Primary tariff with a network device — Energex installs a control device that throttles or pauses the charger during peak demand.
- Primary tariff with a dynamic connection — a two-way communication path between the charger and the network, with import/export limits sent in real time.
In practice, most owners never notice. But a piece of household equipment you own, on private property, now has a remote control held by a third party — and the law requires it. Any new install must accommodate this.
04
Solar generates when the car’s at work — and what’s actually fuelling it overnight.
Most rooftop solar peaks between 10 am and 3 pm, when most cars are at work or school. Without active management you export solar for 5–8¢/kWh during the day, then re-import grid power at 25–35¢/kWh overnight to charge. Net running cost: roughly the same as petrol, once you account for the lost feed-in revenue.
There’s a second issue worth being honest about. EVs are often pitched as “zero-emission” vehicles, but that framing skips a step. The car emits nothing at the tailpipe; the electricity that fills its battery still comes from somewhere. In 2024, fossil fuels generated 64% of Australia’s electricity — coal alone supplied 45%, with gas adding another 17%. Renewables reached 47% across the NEM in Q1 2026, but the headline numbers hide significant state-by-state variation:
- Queensland: 57% black coal, 71% fossil fuels overall
- New South Wales: 60% black coal
- Victoria: 56% brown coal (the most carbon-intensive form)
- Western Australia: 80% fossil fuels
- South Australia: 74% renewables
- Tasmania: majority hydro
The time of day matters more than the annual average. Plug in at 7 pm in Brisbane or Sydney and you’re drawing from a fuel mix dominated by coal and gas baseload. On an Australian coal-heavy grid, an EV’s lifecycle emissions are still roughly 40–50% lower than an equivalent petrol vehicle — power stations are more efficient than internal combustion engines, and the grid mix is improving every year. But “zero emission” is dealership marketing, not engineering reality.
A “solar smart” charger (Zappi, Catch Power) monitors your home’s net export and ramps up to absorb what would otherwise be dumped to the grid — useful if the car is home during the day. For overnight charging, a dedicated EV time-of-use tariff brings overnight rates to 12–18¢/kWh, but doesn’t change the fuel mix. The only way to genuinely decouple your EV from the grid’s coal content is to charge from your own rooftop solar.
05
Apartments and strata are a different problem.
About one in four Australians live in strata-managed buildings not wired for EV charging. Two or three residents installing chargers without a plan trips the building’s main supply. The old answer was: “Sorry, you can’t.” That’s no longer legal in NSW or Victoria, where right-to-charge provisions and the National Construction Code 2022 (in Victoria, since May 2024) require buildings to accommodate charging.
The right solutions: smart shared chargers on common power with individual billing; backbone infrastructure (cable trays, conduit, sub-board) installed once so individual chargers can be added cheaply over time; or managed Level 1 (standard 10 A outlets with metering and load sharing) — slow at 2.4–3.6 kW, but cheap and politically easy to approve. Each owner running their own cable to their own bay costs three to four times more and eventually overloads supply.
06
Hardware quality matters more than it looks.
The Australian charger market runs from $700 dumb units to $2,000+ smart units, and the difference matters more than the price suggests.
Worth paying for: OCPP compatibility (open standard, not vendor-locked — you can change retailers, add solar diversion, and integrate with home batteries); solar awareness / dynamic load management; local control (Wi-Fi-only units become bricks if the manufacturer’s cloud goes down); and full Australian compliance — AS/NZS 3000, AS/NZS 3018, and the AS 4755 demand-response label. Cheap parallel imports often don’t meet these.
You don’t need a charger that does everything — you need one that won’t be obsolete in three years and isn’t entirely dependent on a foreign company’s cloud staying online.
