Charging an EV at home in New Zealand: real costs with road user charges

New Zealand’s electricity is mostly renewable, and EECA says an EV here emits about 90% less CO2 than an equivalent petrol car. For your wallet the question is simpler: how much per 100 km, once road user charges are counted, and which power plan makes home charging cheap.

Cost per 100 km: the official comparison

EECA publishes a running-cost comparison per 100 km:

• EV charged at home, off-peak: about $11
• EV charged at a public fast charger: about $19
• Petrol car: about $19

In other words, home charging off-peak costs a little over half as much as petrol per kilometre. Fast charging on the road costs about the same as petrol.

Doing the sums yourself

The AA’s rule of thumb is that an EV covers about 5 km per kWh, or 20 kWh per 100 km. At 36c/kWh, the AA’s example rate, that is 7.2c per km for electricity: $7.20 per 100 km, or about $72 a month for 1,000 km, adding roughly 200 kWh to your monthly bill.

Then add road user charges. EVs do not pay fuel tax, so since 1 April 2024 they have paid RUC instead. The AA quotes the light vehicle rate as $76 per 1,000 km, which is $7.60 per 100 km. That page has not been updated for some time, so treat the figure as a guide. At the example rate, that puts an EV at about $14.80 per 100 km all in. The AA says off-peak rates are often around half price; at 18c/kWh the total falls to about $11.20, close to EECA’s figure. Before you budget, check the current RUC rate for your vehicle on the NZ Transport Agency website, because rates are set by the government and can change.

Which power plan suits an EV?

Since 1 July 2026, retailers with 5% or more of the market must offer a plan with cheaper off-peak power. The Electricity Authority’s description of a typical time-of-use plan has the night rate, the cheapest, from 11 pm to 7 am, with peaks from 7 am to 10 am and 5 pm to 9 pm. The Authority says about 70% of EV owners already charge overnight to save money.

Some retailers also sell plans aimed at EV owners. From 30 October 2026, the Authority’s code change makes clear that EV and solar plans count as generally available tariff plans, so the usual rules on plan information apply to them too. That makes them easier to compare side by side on Billy, Powerswitch or our comparison page.

Be careful with the rest of the house. A plan with a very cheap night rate can have dearer peak rates. If your heat pump runs hard from 5 pm in winter, the extra cost at peak can eat the EV saving. Compare the whole plan on your own half-hourly data.

What an EV does to your usage

At the AA’s 5 km per kWh, driving 1,000 km a month adds about 2,400 kWh a year. That can change which plan is cheapest for you. If you are on a low user plan, note that the regulations requiring retailers to offer low fixed charge plans end on 1 April 2027, as the Electricity Authority reminded lines companies on 22 September 2026. Many EV households will be better off on a standard or time-of-use plan well before then.

The home charger: rules

Most EVs come with a portable cable that plugs into a normal socket. EECA does not recommend it as your main way to charge. Its advice for a wall-mounted unit:

• It must be installed by a registered electrician.
• It needs its own sub-circuit, with cable rated for at least 32 amps.
• A Type B RCD (residual current device) is required.
• The charger should come with a Supplier Declaration of Conformity.
• Never use extension cords, and never run a charging cable across a footpath.

A smart charger that follows a timer, or your solar output, makes the most of cheap hours. EECA says about 80% of EV owners do more than half their charging at home.

Public charging

Public chargers sit at least every 75 km on most state highways, according to EECA. Speeds vary: a 50 kW charger adds about 50 km in under 15 minutes, a 150 kW unit about 100 km in 13 to 16 minutes. Prices are set by each network and shown in its app; EECA’s $19 per 100 km figure shows fast charging is roughly on par with petrol. Charging to 80% is quicker and easier on the battery.

Incentives in 2026

There is no government purchase rebate listed on EECA’s EV pages in September 2026. The savings are in running costs: cheaper energy per kilometre and, EECA notes, less maintenance because there are fewer moving parts. Battery warranties of around 8 to 10 years or 160,000 km are typical, EECA says.

Pairing an EV with solar

An EV parked at home during the day can soak up rooftop solar that would otherwise be exported at a low buy-back rate. Our solar calculator helps you see how much of your driving the roof could cover, and our guide to solar in New Zealand explains buy-back rates and the new peak export rebates.

When it does not add up

If you cannot charge at home and rely on fast chargers, the running cost is close to petrol, and the purchase price decides. If you drive little, the saving per year is small. For everyone else, the order is: get the charger right, then get the plan right. After a month of EV charging, compare plans again with the new usage, and set a free contract alert so you check again after the 1 April price changes.