The number nobody puts on the quote
Every gas bill in NSW has two parts: what you use, and a fixed daily supply charge of roughly 85 cents to $1.20 a day for the connection itself. That is $310-438 a year, before any gas flows.
If your home runs its cooktop, heating and hot water on gas, that fixed charge spreads across everything. But if hot water is the only gas appliance you have left, the entire connection exists for one tank in the backyard. You are paying $310-438 a year in rent for the privilege of paying for gas on top.
What the maths looks like
For a typical NSW family of 3-4 with a gas storage water heater:
- Gas used for hot water: roughly $800 a year.
- Gas supply charge: roughly $380 a year.
- Total cost of staying: roughly $1,180 a year.
- The same hot water from a heat pump: $220-290 a year on a normal tariff, and close to zero on solar or inside the free 11am-2pm window.
Because switching lets you disconnect gas entirely, the supply charge becomes pure savings. That is why gas-to-heat-pump switches in NSW often pay for themselves in under three years, faster than almost any other home energy upgrade.
Why comparisons keep getting this wrong
Marketing comparisons love to compare usage against usage ("$634 of gas vs $285 of electricity") and quietly leave the supply charge out. That understates the real saving by $310-438 a year, which on this decision is the difference between "meh" and "obvious".
Our calculator asks one question to get this right: do you use gas for anything else, like cooking or heating? If yes, the supply charge stays either way and we count only the usage difference. If hot water is your only gas use, we count the full disconnection. Same honesty, both directions.
Before you disconnect
- Check nothing else in the house quietly uses gas (an old wall heater, a bayonet fitting for a portable heater).
- Ask your retailer what disconnection (abolishment) involves and whether there is a fee, so it goes into your maths too.
- If you keep gas for cooking, the switch can still be worth it. The calculator shows that case separately, without the supply charge saving.