How to work out if an upgrade pays
Find the old appliance's use
Measure it for a week, or estimate from its label and your hours. See measuring energy use.
Find the new one's use
Use the kWh a year on the energy rating label, or the Energy Rating website.
Work out the yearly saving
Difference in kWh a year multiplied by your rate.
Divide the cost by the saving
That is the payback in years. Compare it with how long the appliance will last.
Upgrades with real savings
| Upgrade | Based on | kWh saved | Saving a year |
|---|---|---|---|
| Ten halogen downlights to LEDs | Five hours a day | 840 | $278 |
| Vented dryer to heat pump dryer | Three 6 kg loads a week | 296 | $98 |
| Electric storage to heat pump hot water | 150 litres a day, heat pump at 30% of the energy | 2,005 | $665 |
| 1-star single speed to 5-star variable speed pool pump | 1.1 kW for six hours a day, 55% less energy | 1,325 | $439 |
As an example, if a heat pump hot water system costs $2,000 more than replacing like for like, and saves about $665 a year, it pays back in about 3 years. Government rebates and certificate schemes can shorten that a lot.
Old fridges and freezers
Old fridges are a common case. The SA Government's typical figures put a 400 to 499 litre fridge at 495 kWh a year, about $164 on the Ausgrid reference rate. An older or poorly sealed fridge can use much more. Measure yours for a week. If it uses double the label figure of a new model, the saving may cover a new fridge within a few years.
When not to replace
If an appliance works and is used rarely, keeping it is usually cheaper and avoids waste. Focus upgrades on the things that run the most.
Questions about replacing appliances
Sometimes. Measure the old fridge for a week. If it uses far more than the label figure on a new model of the same size, the saving can cover the cost within a few years.
Those that run a lot: hot water to a heat pump, a single speed pool pump to a 5-star variable speed model, frequent dryer use to a heat pump dryer, and halogen lights to LED.
Work out the kWh a year saved, multiply by your rate for the yearly saving, then divide the extra purchase cost by that saving to get the payback in years.
Sources
Every rate on this page comes from the regulator or the regulated retailer. Last checked October 2026. Prices include GST unless we say otherwise.