10kW Solar Battery Price in Ireland: What 5, 10 and 13.5 kWh Actually Cost in 2026

A 10 kWh solar battery costs €4,500–€7,000 installed in Ireland in 2026. Bought as part of a new solar installation, the battery element typically adds €1,500–€4,000 to the system price, because the labour and the hybrid inverter are already in the job. There is no SEAI grant for any battery, whatever the size, but a battery supplied with a new solar install is usually zero-rated for VAT. Below are the going rates for 5, 10 and 13.5 kWh batteries, and what each size costs per unit of storage.

Solar Battery Prices in Ireland by Size

The spread inside each row is real, not padding. The same 10 kWh of storage costs more when it is a retrofit on an older system (the existing string inverter often cannot manage a battery, so you pay for an extra component), and less when it goes in on day one alongside a hybrid inverter that was in the design anyway. Brand matters too: premium names carry premium labels for broadly similar lithium iron phosphate cells.

The Per-kWh Maths

Divide the installed price by the capacity and batteries get cheaper per unit of storage as they get bigger:

• 10 kWh at €4,500–€7,000 works out at €450–€700 per kWh of storage.
• 13.5 kWh Powerwall 3 at €8,000–€10,000 works out at roughly €590–€740 per kWh, a premium-brand exception to the rule.
• Small batteries cost the most per kWh. A 5 kWh unit is nowhere near half the price of a 10 kWh one, because the fixed costs (installer's day, wiring, commissioning, the inverter's battery capability) are the same whatever size hangs on the wall.

That fixed-cost floor is why installers so often quote 10 kWh as the default. If you are paying for the visit and the electronics anyway, each extra kWh of capacity is comparatively cheap. Whether you can use the extra capacity is a different question, covered below.

No Grant, but Usually No VAT Either

Two rules decide what the State contributes to your battery, and they point in opposite directions:

There is no SEAI grant for batteries. The battery grant was withdrawn in February 2022 when the Microgeneration Scheme arrived, on the logic that homes could now sell surplus power instead of storing it. The current SEAI Solar Electricity Grant of up to €1,800 is calculated on the solar PV element only. If your quote includes a battery, the grant ignores it. Our battery grant guide covers what support exists instead.

The 0% VAT rate usually covers a battery installed with solar. Revenue applies a zero rate of VAT to the supply and installation of solar panels on private dwellings, and installers generally extend that rate to a battery supplied as part of the same installation contract. A battery added later as a standalone retrofit may attract the standard rate instead, which is one more reason the retrofit route costs more. Get the VAT treatment confirmed in writing before you sign either way.

What a 10 kWh Battery Actually Does

A fully charged 10 kWh battery covers around 20–21 hours of a typical Irish home's daily load (average consumption is about 4,200 kWh/year, or roughly 11.5 kWh per day). A 5 kWh unit manages roughly ten hours at light use: fridge, TV, lights. In practice neither is used as whole-home backup. The battery's real job is a daily cycle: soak up the midday solar surplus, then cover the 5pm to 9pm peak when the panels have stopped and grid electricity is at its dearest.

The value of every stored unit is the gap between what your supplier pays for exports and what it charges for imports. Electric Ireland currently pays 19.5c per kWh for exported electricity under the Clean Export Guarantee, while its day rate on a time-of-use tariff runs around 36c. Storing a unit instead of selling it is therefore worth about 16.5c on paper, or 12.9–16.5c once battery losses are counted. Shift 100 kWh a month from export to self-use and that is roughly €198 a year from the store-versus-sell gap alone.

Across a full year, a well-used 10 kWh battery adds around €300–€600 in savings on top of what the panels deliver by themselves. On a dynamic tariff, which every major supplier has been required to offer since 1 June 2026, a further €300–€500 a year is available by charging cheap and discharging dear. Against a €4,500–€7,000 price, that is a payback of roughly 7–12 years. One published worked example from Purevolt, based on an 8 kWh battery and Electric Ireland's April 2026 night and day rates, lands at €420 a year and a 5.9-year payback, at the optimistic end because it assumes disciplined night-rate charging.

So Which Size Should You Buy?

• 5 kWh suits a smaller home with a 2–3 kWp array and modest evening use. You pay the most per kWh, but the total outlay is lowest, and an oversized battery a small array cannot fill earns nothing.
• 10 kWh is the sweet spot for the standard Irish 4–5 kWp system: enough to store a full afternoon's surplus and cover the whole evening peak, at the best mainstream per-kWh price. Sizing guidance for the panels themselves is in our 5 kWp system guide.
• 13.5 kWh and up earns its keep in high-consumption homes: an EV on the drive, electric showers, people in all day. Pair it with a big array or a dynamic tariff, otherwise the top few kWh will sit idle most of the year.

Whether any battery is worth it for your usage pattern is a separate decision from which size, and we have run those numbers in solar panels with a battery: worth it? and the wider battery storage guide.

Frequently Asked Questions