Average battery capacity for household energy storage

Battery storage needs vary based on your household size, energy usage, and goals. For a small household (1–2 people, using 8–12 kWh/day), a 3–7 kWh battery can often cover most evening use. An average household (3–4 people, 16–22 kWh/day) usually benefits from a 7–13 kWh system to maximise solar self-consumption and provide partial backup.

When manufacturers or installers talk about battery capacity (or energy capacity), they usually talk about one of two metrics a battery is rated on: total capacity and usable capacity. We'll get into why those are different further down. For the time being, it's all just "capacity."

In short, battery storage in your home can bring the following benefits: Let's say your home has solar panels on the roof or even a wind turbine in the back garden. Without battery storage, a lot of the energy you generate will go to waste.

Batteries are rated for two different capacity metrics: total and usable. Because usable capacity is most relevant to the amount of energy you'll get from a battery, we like to use usable capacity as the main "capacity" metric to compare storage products. Also, from our energy storage glossary, see how the two terms differ below:

Eguana, Electriq Power, and sonnen currently make the home batteries with the most capacity. Battery capacity can be a misleading metric: in many cases, you can stack multiple batteries together to make a larger system. Compare solar-plus-storage quotes from local installers on EnergySage. What is battery capacity? How is it measured?

Short answer: yes. Domestic battery storage without renewables can still benefit you and the grid. This is especially true for those on smart tariffs; charge your battery during cheaper off-peak hours and discharge during more expensive peak hours, cutting your bills and reducing strain on the grid during peak energy use times.