An off-grid system must be sized for your household’s peak demand, seasonal solar production and the battery capacity needed through cloudy periods. You may also need a backup generator, particularly for homes with electric heating, pumps or other high-load appliances. Costs and eligibility for rebates or other support can vary by state, system design and government rules, so check energy.gov.au and your state program before relying on an incentive. Ask a suitably qualified solar installer to assess the site, confirm electrical compliance and provide a detailed design and quote.