Check that each quote clearly lists the panel and inverter brands and models, system size, expected output, itemised price, deposit and payment terms. Confirm whether the price includes GST, Small-scale Technology Certificate (STC) discounts, installation, electrical work, grid connection and any meter changes. Compare product and workmanship warranties, installer accreditation, exclusions, expected timelines and how export limits may affect your system. Ask an accredited installer to explain the assumptions behind estimated savings, and check connection requirements with your electricity distributor before signing.