What Does a Solar Battery Do?
Without a battery, your solar panels send surplus electricity to the grid during the day (when you're typically at work), and you buy electricity back from the grid in the evening (when you're home and using it). You sell at 15–24c/kWh but buy back at 34c+. A battery bridges this gap by storing surplus solar electricity for later use.
Think of it as a buffer between your solar panels and the grid. It charges during the day with free solar electricity, then powers your home in the evening, avoiding the need to buy expensive grid electricity.
How Much Do Solar Batteries Cost in Ireland?
| Battery Size | Cost Range | Best For |
|---|---|---|
| 5 kWh | €1,700–€3,000 | 1–2 person household, moderate evening use |
| 7.5 kWh | €2,500–€4,000 | Average family home, covers evening peak |
| 10 kWh | €3,000–€5,000 | Larger homes, EV charging, high evening demand |
| 13–15 kWh | €4,500–€6,000 | Maximum self-sufficiency, backup power |
These prices include the battery unit and installation. If you're adding a battery to an existing solar system, you may also need a hybrid inverter (€800–€1,500 extra) unless your existing inverter is already battery-compatible. If you're installing solar and battery together, the hybrid inverter is typically included.
Is a Solar Battery Worth It?
The financial case for a battery depends on the spread between what you pay to import electricity and what you earn from exporting it.
Every kWh you store in a battery instead of exporting saves you the difference between your import and export rate, typically around 15c/kWh. For a 5 kWh battery that cycles once per day during summer months (roughly 200 days), that's about €150 per year. Factor in additional savings from smart tariff arbitrage (charging on cheap night rates, discharging during peak), and annual savings of €200–€500 are realistic.
Payback Period
At €200–€500 annual savings, a 5 kWh battery at €2,000 pays back in 4–10 years. A 10 kWh battery at €4,000 pays back in 8–15 years. The larger the battery, the longer the payback, but the greater your energy independence. Battery lifespan is typically 10–15 years (most carry a 10-year warranty), so a 5 kWh battery is the sweet spot for pure financial return.
Solar With vs Without a Battery
| Metric | Solar Only | Solar + 5kWh Battery |
|---|---|---|
| Self-consumption | 30–40% | 70–80% |
| Annual bill saving | €900–€1,200 | €1,100–€1,600 |
| Export income | €300–€500 | €100–€200 |
| Total annual benefit | €1,200–€1,700 | €1,200–€1,800 |
| System payback | 5–7 years | 6–8 years |
| Power during outages | No | Some models (with backup) |
Best Battery Timing
If you're installing solar now, consider getting a hybrid inverter even if you don't buy a battery yet. Adding a battery later with a compatible inverter is much cheaper than retrofitting the inverter too. Battery prices are falling year on year.
Popular Solar Batteries in Ireland
Several battery brands are commonly installed by Irish solar companies. The right choice depends on your system size, budget, and whether you need backup power.
| Brand | Popular Model | Capacity | Warranty | Key Feature |
|---|---|---|---|---|
| Tesla | Powerwall 2 | 13.5 kWh | 10 years | Full home backup, sleek design |
| Huawei | LUNA2000 | 5–15 kWh | 10 years | Modular, pairs with Huawei inverter |
| GivEnergy | All-in-One | 5–9.5 kWh | 12 years | Integrated inverter + battery |
| Fox ESS | ECS Series | 5.2–10.4 kWh | 10 years | Budget-friendly, reliable |
| SolarEdge | Home Battery | 9.7 kWh | 10 years | Works with SolarEdge optimisers |
| BYD | HVS/HVM | 5.1–22.1 kWh | 10 years | Modular, high-voltage system |
Smart Tariff + Battery: The Advanced Strategy
A battery unlocks an additional money-saving trick: tariff arbitrage. With a smart meter and time-of-use electricity plan, you can charge your battery overnight when electricity is cheapest (16–20c/kWh) and use that stored energy during peak hours (40–50c/kWh). This strategy works even on cloudy days when solar generation is low.
A BER is the starting point for most energy upgrades and grant applications. Homerating.ie has been assessing Irish homes since 2009, with fast turnaround in Dublin and nationwide coverage. Book a BER with Homerating.ie →
Frequently Asked Questions
Yes, in most cases. If your current inverter is battery-compatible (a "hybrid" inverter), adding a battery is straightforward. If not, you may need to either replace the inverter or add an AC-coupled battery system, which adds to the cost.
There is no separate SEAI grant specifically for standalone batteries as of 2026. However, the solar PV grant (up to €1,800) can apply to a system that includes a battery. If you're installing solar and a battery together, the grant applies to the whole system.
Most modern lithium-ion batteries are warranted for 10 years and expected to last 10–15 years. After their warranty period, they typically retain 70–80% of their original capacity rather than failing completely.
Only if it has "backup" or "off-grid" capability. The Tesla Powerwall and some GivEnergy models can provide backup power. Most standard battery setups disconnect during grid outages for safety reasons. If blackout protection is important to you, specify this to your installer.