Home battery storage promises to help you use more of your solar generation rather than exporting it. In Ireland, with electricity prices above 34.38 c/kWh and export rates below import rates, the case is improving, though the maths are still tight.

How solar batteries work

A solar battery stores excess solar generation that would otherwise be exported. When the sun goes down, the battery powers your home instead of drawing from the grid.

For a typical family home:

  • Peak solar generation: 10:00–16:00
  • Peak household demand: 07:00–09:00 and 17:00–22:00

Without a battery: surplus daytime generation is exported at the CEG rate. With a battery: surplus daytime generation is stored and used in the evening.

The financial case

The value of stored energy = import rate − export rate

With Bord Gáis electricity at 41.59 c/kWh and a CEG rate of 18.50 c/kWh:

Value per kWh stored = 41.59 − 18.5 = 23.1 c/kWh

A 5 kWh battery cycling once per day (pessimistic, Irish sun isn’t constant): 5 × 23.1 × 0.5 × 365 ≈ €211/year (assuming 50% of days have surplus to store)

A 10 kWh battery at the same assumptions: ~€350/year

At a cost of €4,000 for a 5 kWh system: payback ~19 years

Source: Bord Gáis Energy, 15 June 2026 Source: SEAI / Bord Gáis Energy, 12 June 2026

When does a battery make financial sense?

Currently, residential battery storage rarely pays back on financial grounds alone in Ireland. The exceptions:

  1. Very high time-of-use tariff spreads: if you’re on a day/night tariff with night rates around 15 c/kWh and charging the battery at night, the economics improve.

  2. EV charging synergy: pairing a battery with an EV lets you maximise cheap off-peak solar charging. If you’d pay 34.38 c/kWh for EV charging otherwise, the savings add up.

  3. Off-grid / resilience value: some rural homes value backup power during outages. This is a non-financial benefit.

  4. Future CEG rate changes: if export rates fall further, batteries become more attractive.

  • Solis / GivEnergy hybrid inverter + battery: popular value option
  • SolarEdge Home Battery: good integration with SolarEdge inverters
  • Tesla Powerwall: premium option, 13.5 kWh capacity

Most installers can quote a battery as an add-on to a new solar install or retrofit to an existing system.

Summary

Financial paybackResilience value
Solar PV alone6–8 years ✓Medium
Solar + battery (financial only)15–20+ years ✗High
Solar + battery (incl. EV charging)10–13 years ◑High

Our recommendation: install solar PV now, use the CEG, and revisit battery storage in 2–3 years as prices fall and tariff structures evolve.