Solar With or Without a Battery: How to Decide

What a home battery actually does

A solar battery stores electricity generated by your panels that is not used immediately in the home, so it can be drawn on later rather than being exported to the grid or wasted. This is most useful when there is a mismatch between when your panels generate electricity, typically through the day, and when your household uses most of its electricity, which for many homes is in the evening.

Without a battery, any solar electricity not used as it is generated is exported to the grid, which can earn payments under the Smart Export Guarantee, but at rates that vary by supplier and are generally lower than the cost of buying electricity back later.

Who tends to benefit most from a battery

Households that are out during the day and use most of their electricity in the evening, for cooking, heating water, charging devices or an electric vehicle, often have more to gain from storing daytime solar generation for later use. A battery can also provide some backup capability in certain systems, though this depends on the specific battery and inverter setup, and not all systems provide backup during a power cut.

Households that use a lot of electricity during the day, for example if someone works from home or runs daytime appliances, may already use a larger share of their solar generation directly, reducing the relative benefit of adding storage.

Cost considerations

A battery adds to the upfront cost of a solar installation, and the payback period depends on your usage pattern, the battery's capacity, and current electricity and export tariff rates, all of which can change over time. It is reasonable to ask an installer to model your household's usage against both scenarios, with and without a battery, so you can compare the difference rather than relying on general assumptions.

Batteries can also be added to an existing solar system later, so the decision does not have to be made all at once, though combining the installation can sometimes be more practical.

Electricity tariffs and timing

Some electricity tariffs offer cheaper rates at certain times of day, and a battery can be charged from the grid during a cheap period as well as from solar, then used during more expensive periods. Whether this is worthwhile depends on your specific tariff structure and should be checked against current offers from your supplier.

Making the decision for your home

There is no single right answer for every household. The decision depends on your usage pattern through the day, your roof's generation profile, your budget, and how you value features such as backup power, where available. Ask an installer to show you an estimate comparing self-use and export levels with and without a battery for your specific circumstances.

EcoMatch can introduce you to an approved installer who can talk through both options and provide a tailored comparison.