The best solar panels can cost more than standard models, but value also depends on efficiency, warranty, performance in your conditions and the installer’s workmanship. As a broad guide, a professionally installed 6.6kW system may cost about $5,000–$12,000 after applicable federal STC discounts, while premium panels or difficult roofs can push the price higher. Your quote should clearly separate panels, inverter, mounting, installation, monitoring and any battery costs. Compare several quotes using CEC-approved products and confirm the final rebate treatment with an accredited installer or energy.gov.au.