Compare more than the panel’s headline wattage: check efficiency, product and performance warranties, expected degradation, temperature performance and the manufacturer’s reputation. A panel with a higher efficiency rating may be useful where roof space is limited, while a lower-cost option could suit a larger roof. Also compare the inverter, mounting system, installation workmanship and the system’s estimated annual output, not just the total price. Ask several Clean Energy Council-accredited installers for itemised quotes, and check current rebates and Small-scale Technology Certificate rules through energy.gov.au before deciding.