Solar panels with battery storage

Without storage, generation you do not use at the moment it is produced is exported. With storage, surplus charges a battery during the day and is discharged in the evening, so more of your own generation displaces electricity you would otherwise buy.

Some households also use a battery with a time-of-use tariff, charging from the grid when import rates are low. Whether that is worthwhile depends entirely on the tariff available to you.

• Households that use most of their electricity in the evening rather than at midday.
• Homes with a large enough array to produce regular surplus in the lighter months.
• People on tariffs with a wide gap between peak and off-peak import rates.
• Households wanting some resilience during a power cut, where the equipment supports it.

A battery is less compelling where the array is small, where most generation is already used as it is produced, or where the export rate is unusually generous.

Batteries are described in kWh of usable capacity, which is not always the same as nameplate capacity. Sizing follows your evening consumption and typical surplus, not the biggest unit available. Also check usable versus total capacity, continuous power output in kW, round-trip efficiency, warranty terms including cycles or throughput, whether the inverter is hybrid or a separate AC-coupled unit, and where the battery will physically go.

Storage adds meaningful cost to a system and typically lengthens payback rather than shortening it, while increasing the share of your generation you actually use. Some households value that; others are better served by spending the same money on more panels, or on nothing at all. Any indicative figures we show for a system with storage are estimates based on your answers, not a quotation.