The most expensive appliances to run in NZ homes
Most power bills are dominated by a handful of appliances. The rest - lights, the TV, your laptop - barely register. If you want a smaller bill, it pays to know which few things are doing the damage - in other words, which appliances use the most electricity in a New Zealand home. Here is the ranking for 2026.
The dollar figures below assume a representative blended price of about 40c per and typical usage. Your numbers will shift with your region's price and how hard you run each thing - the calculator lets you plug in your own.
1. Spa pool / hot tub - around $120-180/month
Nothing else in a normal home comes close. A spa pool kept hot and ready year-round draws power continuously to fight heat loss, and the pump cycles on top of that. Kept at temperature 24/7 it commonly adds $120-180 a month - more in winter, more again if it is outdoors and poorly covered.
The fix is not to drain it. A good cover, dropping the set temperature a couple of degrees, and a timer that lets it cool between uses can take a big bite out of that. See the spa pool cost breakdown.
2. EV home charging - around $80-130/month
An electric car is cheaper per kilometre than petrol, but it is still a large new load on your bill. A typical 250 km/week commute adds roughly $80-130 a month charging at home. The single biggest lever is when you charge: shifting it overnight onto a plan can cut the charging cost by about a third. Full EV charging guide.
3. Hot water cylinder - around $80-120/month
Water heating is one of the two biggest slices of almost every NZ bill (heating is the other). An electric cylinder for a family runs $80-120 a month. The good news: most cylinders are on and heat overnight at the cheaper night rate, so the real cost is often lower than the headline. Wrapping an old cylinder, fixing dripping hot taps and shorter showers all help. Hot water cylinder cost.
4. Instant electric shower - around $60-90/month
A 9,000-watt instant shower has a frightening wattage, but it is only on while the water runs. For a household taking a few showers a day it still lands around $60-90 a month - and unlike a cylinder it is billed at the full day rate, because it heats on demand.
5. Clothes dryer - around $40-60/month (vented)
A vented dryer is one of the highest-wattage things in the house at about 4,500 watts. Run a few loads a week through winter and it is $40-60 a month. A heat pump dryer uses roughly a third of the electricity per load, and a clothesline uses none. Heat pump vs vented dryer.
6. The second fridge - around $30-50/month
The garage beer fridge is the hidden cost nobody counts. An older second fridge or chest freezer running 24/7 adds $30-50 a month - $400-600 a year for somewhere to keep drinks cold. If it is half-empty most of the year, switching it off is free money. Second fridge cost.
7. Heating - heat pump or, worse, plug-in heaters
Space heating is about 30% of the average NZ home's energy use across the year, but it is seasonal. A heat pump used sensibly is one of the cheapest ways to heat (around $30-90 a month in winter); a plug-in oil or fan heater doing the same job costs roughly three times as much. If you heat with plug-in electric heaters, that is often your biggest winter cost after hot water.
The quiet one: the heated towel rail
It is only 80 watts, so it never feels like a culprit - but left on 24/7 it runs about $200 a year, more than many people's fridge. A $20 timer fixes it. Why the towel rail costs $200 a year.
The maths behind one number
None of these figures are magic - they all come from the same simple formula: kilowatts, times hours, times days, times your rate. Take the vented dryer as a worked example. It draws about 4,500 watts (4.5 kW) and a typical load runs around an hour. A household doing five loads a week:
- 4.5 kW × 1 hour = 4.5 kWh per load
- 4.5 kWh × 5 loads = 22.5 kWh per week
- 22.5 kWh × 4.33 weeks = about 97 kWh per month
- 97 kWh × 40c = $39 a month, and more in a wet winter when loads pile up
Swap in a heat pump dryer at roughly 1.5 kWh per load and the same five loads a week cost about $13 a month - a third of the price, for the same dry washing. That single comparison sums up this list: the wattage on the label tells you how greedy a thing is, but it is the wattage times the hours that lands on your bill.
The big hitters at a glance
Here is the ranking as a single table, with rough monthly energy use and cost at a 40c blended rate. Heavy seasonal items (the spa pool, plug-in heaters) sit at the winter end of their range.
| Appliance | Use (kWh/mo) | Est. cost/mo |
|---|---|---|
| Spa pool / hot tub (kept hot) | 300-450 | $120-180 |
| EV home charging (250 km/wk) | 200-325 | $80-130 |
| Hot water cylinder (family) | 200-300 | $80-120 |
| Instant electric shower | 150-225 | $60-90 |
| Vented clothes dryer | 100-150 | $40-60 |
| Plug-in heater (winter) | 90-200 | $35-80 |
| Second / garage fridge | 75-125 | $30-50 |
| Heat pump (winter heating) | 75-225 | $30-90 |
| Heated towel rail (24/7) | ~60 | ~$25 |
Because everything scales with your rate, you can adjust the whole table for your town in your head. A Wellington home at 37c pays roughly 8% less than these figures; a Balclutha home at 52.5c pays about a third more. So a spa pool that costs $150 a month in the table is closer to $140 in Wellington and almost $200 in Balclutha - same tub, same temperature, different network. Tick your own region and appliances in the calculator to get the exact numbers instead of these averages.
What barely matters
Worth saying, because people worry about the wrong things: LED lights, phone chargers, the TV, a laptop, the wifi router - individually these are cents to a couple of dollars a month. Standby power across the whole house adds up to maybe 5-10% of the bill. Turning the TV off at the wall is fine, but it will never move your bill the way the spa pool or the dryer will.
Where to start
Look at your own top three rather than a generic list. Tick your actual appliances in the calculator and it ranks them by cost and flags the gotchas - the second fridge, the towel rail, the spa pool - so you spend your effort where the dollars actually are.
Related guides
- How much does it cost to charge an EV at home? - the fastest-growing line on many NZ bills
- How much does a heat pump cost to run in NZ? - why it beats every plug-in heater
- Is your heated towel rail costing you $200 a year? - the small appliance that punches above its weight
- Average NZ power bill by region (2026) - put these appliance costs in context of the whole bill