A home solar system’s payback period is the time needed for electricity bill savings and other benefits to recover its upfront cost. In Australia, it often falls somewhere between several years and more than a decade, depending on system price, household energy use, self-consumption, feed-in tariffs, available rebates and future electricity rates. A battery can change the calculation substantially, so compare its extra cost with the value of using stored energy. An installer can provide an estimate based on your usage, while the actual result will depend on your system’s performance and energy prices.