In 2026, eligible solar water heaters and air-source heat-pump systems may qualify for Small-scale Technology Certificates (STCs), which can reduce the upfront price through an approved supplier or installer. Some states and territories also offer their own rebates or incentives, but rules, product requirements and availability vary. Your likely savings depend on the system, location, installation and household hot-water use, and any incentive is ultimately determined under the relevant scheme. Check the current details at energy.gov.au and with an accredited installer before comparing quotes.