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Battery Sizing Calculator
Find the right battery size for your solar system based on your usage and backup needs.
Average Irish home: 11.5 kWh/day
Battery recommendation
Recommended size
7.5 kWh
Estimated cost
€5,250
Annual saving
€818/yr
Payback period
6.4 years
SEAI gives a €600 grant for a battery of 5 kWh or more if your home was built and occupied before 2025. Smaller batteries get no grant. 0% VAT applies when installed with solar panels.
When are you thinking of doing this?
We'll only match you to contractors when you're ready.
Next steps
Grant information last reviewed: June 2026. Always verify at seai.ie.
Official SEAI Resource — always verify grant details directly with SEAI before applying.
Last verified: 2026-06-01