What size solar battery do I need for my home?

Capacity is not power

A battery’s kilowatt-hour figure describes energy storage. Its kilowatt rating describes how quickly energy can move in or out. A battery can have plenty of stored energy yet still be unable to supply every appliance at once.

Use a realistic daily pattern

Look at daytime solar surplus, evening and overnight demand, and seasonal differences. A battery that fills regularly in summer may behave very differently in winter. Reserve settings and conversion losses also reduce the energy available for ordinary household use.

Avoid a fixed panel-to-battery rule

Two homes with identical roofs can need different storage because their usage differs. Ask for the sizing assumptions and compare more than one practical option. VERA can record battery interest for the quote conversation; a roof assessment alone does not establish an optimised household battery size.

Compare two sizes on the same assumptions

For each option, request the installed price, usable capacity and expected extra annual benefit. Ask how often the larger battery would fill and be used in the model. Paying for capacity that the household rarely uses should be an explicit choice, not an automatic upgrade.

• Compare battery storage costs