I advise endeavoring to trim the trees if possible, but or else Microinverters or S/E with Optimisers do the job good with some overshadowing. Once-a-year value estimates think general energy utilization of 4000kWh/12 months for just a residential buyer on just one price tariff. Cost estimates exclude solar feed-in tariff https://citypointsolar.com.au/7-7kw-solar-system-installation-perth/