Solar panel costs in Australia vary with system size, panel and inverter quality, roof access, location and installation requirements. As a broad guide, a residential system around 6.6kW may cost several thousand dollars after applicable incentives, but prices change and this is not a quote or guaranteed saving. Batteries, switchboard upgrades, monitoring and difficult roof work can add substantially to the total. Ask several accredited installers for itemised quotes and check current incentives through energy.gov.au or your state or territory government before deciding.