Hot water rebates and running costs in Australian Capital Territory
The one place gas wins on every measure, and loans instead of rebates.
What a hot water system costs to run in Australian Capital Territory, what you can claim towards replacing it, and the local facts that change the answer here — the tariff structure, the climate and the grid.
What you can claim in Australian Capital Territory
Federal Small-scale Technology Certificates
$800–$1,200 off an eligible heat pump or solar thermal system
Available in every state. The installer claims the certificates and discounts your quote, so there is nothing for you to lodge. Australian Capital Territory sits in STC Zone 4, the lowest-value zone. Gas and electric resistance systems create no certificates.
Administered by the Clean Energy Regulator. Official scheme page. Last verified 5 September 2026.
Sustainable Household Scheme and ActewAGL water heater upgrade
Zero-interest loans rather than a cash rebate, plus a discounted upgrade through ActewAGL
- The ACT's distinctive offer is finance, not a rebate: a zero-interest loan spreads the up-front cost instead of reducing it.
- A separate discounted water heater upgrade is offered through ActewAGL.
Administered by ACT Government. Official scheme page. Last verified 5 September 2026.
Why Australian Capital Territory is different
The Australian Capital Territory is the exception that makes the rest of this site's argument credible. ActewAGL's standing rate of 37.0c per kilowatt hour is the second highest in the country, the climate is the coldest on the mainland, and the grid is supplied through New South Wales at 0.64 kg CO₂-equivalent per kilowatt hour. Put those together and gas instantaneous currently wins in Canberra on running cost, on ten-year total cost, and on emissions.
The numbers, for a three-person household that also cooks with gas: gas instantaneous about $449 a year against a heat pump's $526; $6,841 against $9,113 over ten years even after the federal certificates; 543 kg of CO₂-equivalent against 824. There is no reading of those figures that makes a heat pump the cheaper choice in Canberra today, and we are not going to pretend otherwise.
Two things change that. If hot water is the only thing you use gas for, the whole daily supply charge is part of what hot water costs you and the heat pump wins on running cost — $526 against $610 — though gas still edges the ten-year total. And as the grid decarbonises the emissions comparison will reverse, at which point a heat pump installed now is already in place.
The ACT's assistance is also structurally different from everywhere else. Rather than a cash rebate, the Sustainable Household Scheme offers zero-interest loans, which spread the up-front cost rather than reducing it. A separate discounted electric water heater upgrade is offered through ActewAGL. If your obstacle is finding $4,000 at once rather than the total cost, the ACT's approach is arguably more useful than a rebate — but it is not the same thing, and the calculator does not count a loan as a reduction in cost.
The territory also has the most expensive controlled load rate in the country at 27.8c, so the off-peak strategy that rescues electric storage elsewhere saves less here.
Every system at Australian Capital Territory prices
A three-person household using 120 litres of hot water a day, at Australian Capital Territory's reference rates and the Canberra climate. On these assumptions the cheapest system to run in Australian Capital Territory is solar thermal with gas boost at about $349 a year.
| System | Cost per year | Rebates | 10-year total | CO₂e a year |
|---|---|---|---|---|
| Solar thermal with gas boost | $349 | −$800 | $9,193 | 240 kg |
| Gas instantaneous | $449 | — | $6,841 | 543 kg |
| Heat pump | $526 | −$800 | $9,113 | 824 kg |
| Gas storage | $549 | — | $7,890 | 736 kg |
| Solar thermal with electric boost | $672 | −$800 | $12,418 | 1058 kg |
| LPG instantaneous | $775 | — | $10,101 | 632 kg |
| LPG storage | $1,098 | — | $13,379 | 865 kg |
| Electric storage | $1,124 | — | $13,142 | 1945 kg |
A three-person household in Australian Capital Territory using 120 litres of hot water a day, at 37.0c/kWh and 2.72c/MJ for gas, with the Canberra climate and the Australian Capital Territory grid's emissions factor of 0.64 kg CO₂e per kWh. Change any of it in the calculator.
Your own household will differ. Put your bill figures into the calculator and every number above recalculates.
The certificate value is falling every January
The federal scheme is winding down on a fixed schedule. Certificates are deemed over a period that shortens by one year every 1 January, and the scheme ends in 2030 — so the same system installed in Australian Capital Territory in December earns about a fifth more than it would a few weeks later.
| Install year | Deeming period | Indicative value |
|---|---|---|
| 2025 | 6 years | — |
| 2026 (now) | 5 years | $800–$1,200 |
| 2027 | 4 years | $640–$960 |
| 2028 | 3 years | $480–$720 |
| 2029 | 2 years | $320–$480 |
| 2030 | 1 years | $160–$240 |
The certificates a heat pump creates are deemed over a period that shortens by one year every 1 January until the scheme ends in 2030. Waiting from December to January costs about a fifth of the discount, for exactly the same system. It is the one piece of timing advice on this site that is worth acting on.
How the ACT compares
The ACT is the only jurisdiction offering a loan rather than a cash discount for hot water. Victoria sits at the opposite end, stacking three separate cash rebates into the richest hot water incentive in the country, while Queensland runs no state scheme at all — federal certificates only.
Frequently asked questions
Which hot water system is cheapest to run in the ACT?
Solar thermal with a gas boost, at about $349 a year for a three-person household using 120 litres a day on Canberra's reference rates — though it also costs the most to install, so weigh that against the ten-year column above before committing.
What is the ACT's hot water rebate actually worth?
Between $800 and $1,200 combined, from the federal certificates plus the Sustainable Household Scheme and the ActewAGL water heater upgrade — though the Sustainable Household Scheme itself is a zero-interest loan, not a discount, so it spreads the cost rather than cutting it. The exact figure depends on system capacity and the certificate price on the day.
What does electricity cost for hot water in the ACT?
37.0c per kilowatt hour plus a $1.34 daily supply charge, from the ICRC's 2026–27 recalibration effective 1 July 2026 — with a controlled-load circuit available at 27.8c, the most expensive off-peak rate in the country. Retailer market offers often undercut this reference rate, so use your own bill in the calculator.
Does a heat pump cope with Canberra's climate?
It works, but at the lower end of its range — an effective coefficient of performance around 2.14 against a nameplate 3.2, because Canberra's air has less heat in it to extract. Even there it still uses under half the electricity a resistance element would, which is why it stays the cheapest electric option despite the cold.