A Pv panels photovoltaic (PV) system is a packaged, connected assembly of photovoltaic solar cells available in different voltages and wattages.4kW Solar Panel Price is generally cost around $4400-$8400 (including installation). This price can vary depending on the quality of the system you choose and the state or territory in which you install it. 9kW Solar PV System in Perth, WA system is most suitable for users with higher energy consumption.If you are a commercial customer and consume between 35 kWh and 50 kWh, a 9kW solar system might be a good choice to reduce your energy costs. The 9kw solar system for home benefits the huge energy demands. Depending on where you are in Australia.The humble 1.5kW Solar Power systems Australia most popular solar power system from about 2011 to 2013. It has now been overtaken in popularity by the 6kW system.