The main options are electric or gas storage systems, instantaneous gas systems, heat pumps and solar hot water systems. Your best choice depends on household size, available energy connections, climate, installation space, budget and whether you prioritise lower upfront or ongoing costs. A licensed plumber, and sometimes an electrician, can assess your home, size the system and ensure the installation meets Australian requirements. Compare models and check current government information or state rebates through energy.gov.au before deciding, as eligibility and savings depend on your circumstances.