A home battery stores spare solar electricity so you can use it later, usually in the evening. Whether one is worth it depends on how you use power, the size of your solar system and what it costs. This guide is general education, not a technical assessment of your home.
How a home battery works
During the day your panels may produce more electricity than the home needs. Without a battery, the surplus goes to the grid, and few Irish suppliers currently pay well for it. A battery captures that surplus, then supplies it to your home when the panels are quiet. SEAI’s advice is to aim to use as much of your own solar electricity as possible.
Capacity and power are different
- Capacity (kWh) is how much energy the battery can store. Usable capacity is usually lower than the headline figure, because batteries are not designed to be fully drained and lose some energy when charging.
- Power (kW) is how quickly the battery can charge and supply the home. A battery with plenty of capacity but low power may struggle to run several appliances at once.
When storage may be worth considering
- You use a lot of electricity in the evening and early morning, when panels produce little.
- You are installing a larger solar system, as SEAI notes that systems above about 2 kW export more without storage.
- You would like some protection against rising electricity prices.
For a smaller system, a hot water diverter that heats your immersion with spare solar power can be a lower-cost way to use more of what you generate. Ask installers about both.
Grants and cost
The Government announced a new €600 SEAI grant for home batteries in September 2026, and eligible welfare recipients may qualify for higher support that includes a 5 kWh battery. See our solar grants guide. A battery usually costs several thousand euro, so the grant covers only part of the cost.
What to compare in battery quotes
- Usable capacity in kWh and power output in kW.
- Warranty length and the number of charge cycles it covers.
- Whether the battery is AC-coupled or DC-coupled with the inverter, and whether it can be added later to an existing system.
- What happens during a power cut: some systems need extra equipment to provide backup power.
- The total installed price, shown separately from the solar panels.
Our quote comparison guide has a fuller checklist.