Key takeaways
- Electric storage is cheapest to buy and most expensive to run; heat pump is the reverse.
- Heat pump and solar both attract federal STCs plus the SA Energy Productivity scheme - $1,000 to $1,800 off.
- Every new install must include a compliant tempering valve under AS 3498.
- Match the system to your household: existing fuel, roof aspect, household size, and how long you will stay.
The four types of hot water system
Adelaide homes run on one of four hot water types. Electric storage heats water in an insulated tank with an element. Gas - either a storage tank or a continuous flow unit - heats with a gas burner. Solar uses roof collectors with an electric or gas boost. A heat pump works like a reverse air-conditioner, pulling warmth from the air to heat the water.
They differ on two axes that matter: what they cost to buy, and what they cost to run. The cheapest to buy is rarely the cheapest to own.
What each one costs in Adelaide
Real Adelaide supply-and-install pricing runs roughly as follows. Electric storage: $1,400 to $3,200. Gas storage: $1,600 to $3,000. Gas continuous flow: $2,400 to $3,800. Heat pump: $4,500 to $5,500 before rebates, or about $2,800 to $5,200 after them. Solar: $3,800 to $6,500.
Heat pump and solar both trigger federal Small-scale Technology Certificates, and heat pumps also qualify under the SA Energy Productivity scheme. Together those rebates typically take $1,000 to $1,800 off the upfront price. Always ask for the post-rebate figure in writing.
Running cost is where the decision is made
A heat pump uses roughly one third of the energy of an electric tank for the same hot water, because it moves heat rather than generating it. For a typical 4-person Adelaide household that is $400 to $600 a year saved against electric.
That is why a heat pump, despite the higher sticker price, is usually the cheapest system to own over 10 years. Continuous flow gas comes next by removing standby heat loss. Solar performs strongly in Adelaide thanks to the local sun, particularly for households with steady, predictable demand.
Which system suits your home
A few rules of thumb. If you have an existing gas connection and a household of 3 or more, continuous flow gas is a strong, lower-cost choice. If you have an electric tank, plan to stay in the home long-term, and have roof space, a heat pump usually wins on total cost. Solar suits households with predictable usage and a long tenure.
Every new installation in SA must include a compliant tempering valve that limits the bathroom outlet to 50 degrees Celsius, under AS 3498 and the Plumbing Code of Australia. It should be a line item in every quote.