Battery storage8 min readLast reviewed 20 August 2026

Do I need a battery?

Understand when storing your own solar energy could be useful for your home.

A battery can move electricity from one time to another, but it does not create extra solar generation. The useful question is not whether batteries are good in general. It is which problem storage would solve for your home, what the complete installation would cost and how the result compares with solar alone.

Start with the problem you want to solve

Storage may be worth exploring if you regularly have solar surplus that you cannot use at the time, want to shift some grid electricity away from a more expensive period, or need a clearly specified backup function. Those are different objectives. Ask the installer to show which one the proposal addresses and what evidence from your household supports it.

Your daily pattern matters

Compare when the home uses electricity with when the proposed solar array is expected to generate it. A home that can run appliances, heat water or charge a car during daylight may already use more solar directly. A home with a regular daytime surplus may have more energy available to store. Annual totals alone do not show this timing.

Capacity and power are separate

Usable capacity, measured in kWh, describes how much energy can be stored within the product's operating limits. Charge and discharge power, measured in kW, describes how quickly electricity can move in or out. A large capacity does not guarantee that the battery can support every appliance or absorb every short solar peak. Ask for both figures and the assumptions used to choose them.

Cost means the complete installed scope

Compare more than the battery cabinet. The quote may need to include an inverter or control equipment, protection devices, electrical work, metering, commissioning, monitoring, a suitable location and any changes needed to an existing solar system. A lower headline price can describe a different scope, so use exact model numbers and written inclusions.

Tariffs can change the case in both directions

A battery may be operated using solar surplus, grid charging, or a mixture of both. Import rates, export rates, time windows, standing charges, product rules and control settings all matter. Treat any tariff in a proposal as dated evidence, not a permanent promise, and compare the battery case with the same tariff assumptions used for the solar-only case.

Backup is not automatic

Some systems can keep selected circuits running during a power cut, while others stop when the grid fails. Backup may require extra hardware, a separate consumer unit or operating limits that affect what can be powered. If resilience matters, ask what runs, for how long, under which starting state and whether the feature is included in the quoted price.

So, are solar batteries worth it?

There is no universal answer. A defensible comparison shows the same solar design with and without storage, uses household-specific timing where available, separates bill savings from export income and includes losses, degradation, warranty limits and the full installed cost. If the proposal cannot show those differences clearly, it is too early to reach a conclusion.

Key takeaways

Decide which problem storage would solve before choosing a product or capacity.
Compare usable kWh, charge and discharge kW, compatibility and installed scope separately.
Treat tariff assumptions as dated inputs and compare solar-only with solar-plus-battery on the same basis.
Do not assume backup power is included or that a battery can run every household load.
A battery can shift energy in time; it does not create extra solar generation.

This guide is for general information only. It is not a substitute for a survey of your home or professional advice. Solar Help Centre does not install solar equipment or produce the final design for your home.

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