In 2026, support for a solar hot water system may include federal Small-scale Technology Certificates (STCs) and, depending on your location, a state or territory program. The value and eligibility can depend on the system, installation address, replacement of an existing heater, and whether the product and installer meet the scheme rules. An eligible installer or retailer may assign the STC discount to your quote, but the final amount is not guaranteed. Check current details on energy.gov.au and your state or territory government website before signing a contract.