A solar battery stores excess electricity produced by your panels during the day so it can be used at night or when solar production is low. It can increase your use of home-grown energy, but it does not generate electricity itself, and backup power during an outage depends on the battery, inverter and installation. Whether it is worthwhile depends on your electricity use, feed-in tariff, battery size, usable capacity, upfront cost and expected lifespan. A Clean Energy Council-accredited installer can assess your home and explain suitable options.