Compare more than the panel’s efficiency rating: check the product warranty, performance warranty, degradation terms and suitability for your roof and climate. Choose panels listed on the Clean Energy Council’s approved product list, and use an installer who is appropriately licensed and accredited for the work. Get several itemised quotes covering panels, inverter, monitoring, installation, export limits and any battery options. Check the installer’s experience and after-sales support, and confirm likely output using your roof orientation, shading and local electricity usage rather than relying on headline claims.