Time-of-use and free hours power plans in NZ: who saves and how to check

New Zealand’s power system is busiest on cold weekday evenings, when everyone gets home, turns on the heat pump and starts cooking. Power costs more to supply at those times and less in the middle of the night. A time-of-use plan passes some of that difference on to you, and since 1 July 2026 the large retailers have had to offer one. Whether it saves you money depends almost entirely on when your household uses power.

How time-of-use pricing works

Instead of one price per kWh all day, the day is split into bands. The Electricity Authority gives the typical pattern:

• Peak: 7 to 10am and 5 to 9pm, the most expensive.
• Shoulder (off-peak): 10am to 5pm and 9 to 11pm, a middle price.
• Night: 11pm to 7am, the cheapest.

Retailers set their own windows. Electric Kiwi’s MoveMaster plan, for example, uses a weekday peak of 7 to 9am and 5 to 9pm, treats weekends from 7am to 11pm as off-peak, and has its lowest rates from 11pm to 7am. Powerswitch describes peak as generally 7 to 11am and 5 to 9pm on weekdays. Read the exact hours on the plan you are looking at.

Since 1 July 2026, retailers with at least 5% of the market must offer a plan with cheaper off-peak rates. Consumer NZ lists five that qualify: Mercury, Genesis, Contact, Meridian and Powershop, which together cover about 85% of the market.

Free hours plans

A variation gives you a window of free power instead of a cheaper rate. Two examples, both checked on 9 October 2026:

• Contact Good Nights: free electricity from 9pm to midnight, Monday to Friday. The daily charge still applies, gas is excluded, you need an actively communicating smart meter, and it is not available with solar. There is no fixed term, and a fair use limit applies if your free-period use averages more than 200 kWh a week.
• Electric Kiwi Hour of Power: every Electric Kiwi customer gets one free off-peak hour a day, chosen between 9am and 5pm or 9pm and 7am.

Free is attractive, but look at the rest of the price list. Powerswitch warns that the rate outside the free hours can be higher than on a standard plan. Contact’s own advice is to shift existing use into the free window rather than add new use.

Who actually saves

Powerswitch says households that manage a time-of-use plan well typically save about 20% on their power bills. The ones who get there have loads they can move without much pain.

EV owners. This is the clearest case. The Electricity Authority says about 70% of EV owners already charge overnight. Powerswitch’s Paul Fuge told Consumer NZ in July 2026 that a time-of-use plan can cut charging costs by 40 to 50%. Set the car or charger to start after 11pm and it happens without thinking. Our guide to charging an EV at home has the running costs.

Electric hot water cylinders. A cylinder is a battery for heat: it can warm up overnight and keep the water hot for the morning. Several retailers now offer smart hot water control. Consumer NZ reported in July 2026 that Meridian and Powershop give eligible customers a $10 monthly credit, Octopus says savings could be up to $150 a year, and Electric Kiwi’s trial customers saved an average of $14.54 a month. Lines companies have used ripple control on cylinders for decades on the same principle. Retailers do not guarantee you will never run short, so a big household should watch the first few weeks.

Pools, spa pools, dishwashers and dryers. Anything with a timer or delay start can move into the night or the free window.

Heat pumps. Harder. Winter heating in Dunedin or Rotorua is needed exactly in the 5 to 9pm peak, and you cannot sensibly move it to 2am. Running the heat pump in the late afternoon shoulder period so the house is already warm by 5pm can help a little. Homes that heat with gas have less to shift, and the Electricity Authority lists them as less suited to time-of-use.

Who often loses. Families with young children, who need power at all hours. Consumer NZ quotes Powerswitch’s example of someone who changed nothing and went from paying 25 cents at peak to 40 cents. Everyone in the house has to be on board.

How to read your own usage

You need a smart meter for any of this, because the plan is billed on half-hourly readings. Your retailer’s app may already show use by hour. If not, ask for your data. Under the Electricity Authority’s rules a retailer must give you your consumption information within five business days of a complete request, by phone or email, and must not charge for a normal request. Ask for the half-hourly file for the last 12 months.

Then look for three numbers: the share of your kWh in the peak, the shoulder and the night. A winter month and a summer month are enough for a first look, since NZ usage swings hard between them. If most of your power goes on in the evening peak and you cannot move it, a flat plan is probably safer.

Comparing time-of-use with a flat plan

The honest comparison is simple arithmetic:

1. Add up your kWh in each band for a year, or for one winter and one summer month and scale up.
2. Multiply each band by the time-of-use plan’s rate for that band. Subtract any free hours you would genuinely use.
3. Add the daily charge times 365.
4. Do the same with the flat plan’s single rate and daily charge.
5. Compare the totals, then repeat with the changes you would realistically make, such as moving the EV and the dishwasher after 11pm.

Billy and Powerswitch both have a time-of-use filter that shows the plans available at your address, and our compare page links to them. If you are not sure which appliances matter, the appliance calculator shows what each one uses.

Try it without locking in

Powerswitch and Consumer NZ both suggest starting on an open-term plan, so you can go back if it does not work. Check the app after the first month to see whether your use really moved. If you are being offered a joining credit for a fixed-term time-of-use plan, our guide to joining credits shows how to weigh it. Then compare again when your habits or your household change, and set a contract alert if you do fix.