2026 prices, installation included: 5 and 10 kWh batteries, retrofits on existing systems, Tesla Powerwall and Huawei LUNA2000, and the 50% tax deduction.
In 2026 a storage battery installed on an existing solar system costs €700–1,100 per kWh: about €3,000–5,500 for a 5 kWh unit and €6,500–10,000 for a 10 kWh one, VAT included. Installed together with a new system it costs nearly half, and the 50% tax deduction halves the effective outlay.
Let’s go through prices size by size, what a retrofit costs, what the most requested models cost — Tesla Powerwall and Huawei LUNA2000 — and how the deduction works. If you’re still wondering whether a battery pays off at all, the full math is in our guide to whether storage is worth it.
How much does a 5 kWh battery cost?
Between €3,000 and €5,500 installed. It’s the entry size, right for a 3 kW system and a small family with normal evening consumption: it covers dinner, appliances and the night hours.
With the 50% deduction the effective cost drops to €1,500–2,750, recovered over ten years. Rule of thumb: the battery should store roughly what you consume between sunset and morning.
How much does a 10 kWh battery cost?
Between €6,500 and €10,000 installed as a retrofit. It’s the most requested size: a family of 3–4, significant evening consumption, perhaps a heat pump or an electric car on the way.
If you’re doing everything at once, the complete package — 6 kW system + 10 kWh battery — currently costs €12,000–17,000 turnkey (typically €13,000–15,000). All system prices, size by size, are in our 2026 solar cost guide.
Adding it to an existing system: what does a retrofit cost?
A retrofit costs more per kWh — €700–1,100 versus the €400–600 of a battery installed together with the system — because the installation shares nothing: it needs dedicated labour (around €800–900), paperwork to update the grid connection and, depending on the system, a hybrid inverter or a separate battery inverter.
In practical terms: if you’re planning your system now and know you’ll want a battery, install it right away. If you already have a system, a retrofit still pays off in most cases — you just need the right solution for your inverter, which is exactly what we check during our site surveys across Umbria.
Want to know what size your home needs and how much you’d save? The simulator tells you in two minutes.
How much does a Tesla Powerwall cost? And a Huawei LUNA2000?
The two names we’re asked about most, with indicative installed prices:
- Tesla Powerwall 3 (13.5 kWh): €7,500–10,500 VAT included. The list price starts at €6,900 + VAT (plus the Gateway): thanks to its high capacity it offers one of the best €/kWh in the premium range, €550–800 per kWh. 10-year warranty with 70% capacity guaranteed.
- Huawei LUNA2000: modular from 5 kWh up — roughly €3,700–4,800 for 5 kWh and €5,500–7,500 for 10 kWh installed. Warranty up to 15 years on the latest series.
Actual prices depend on availability, promotions and installation complexity: always ask for an up-to-date quote. You’ll find these and the other systems we install (WECO, Azzurro, SolarEdge, LG) in the storage section of our solar page.
Does the 50% deduction apply to the battery alone?
Yes. In 2026 the tax deduction — 50% on a primary residence, 36% on other homes — also covers a battery installed on its own onto an existing system: you recover half the cost over 10 annual instalments. It requires the traceable “talking” bank transfer and the ENEA notification, which we prepare for you. VAT is 10%.
A concrete example: a 10 kWh battery costing €8,000 effectively costs you €4,000 — €400 back per year for ten years. Note: from 2027 the rates drop to 36% and 30%, so installing by December locks in the full deduction. Details on our incentives page.
Is it worth it? The short version
Every kWh the battery shifts from selling (€0.05–0.11) to self-consumption (€0.25–0.32) is worth about €0.20. A well-sized battery lifts self-consumption from 30–35% to 70–80% and typically pays for itself in 7–12 years with the deduction — against a useful life of 15–20 years. The full math, including the cases where waiting is smarter, is in our worth-it guide.
Tell us how much you consume and what system you have (or want): we’ll reply with a precise price and the right size, no strings attached.
Indicative prices as of July 2026, 10% VAT included, based on national guides and price lists (Enpal, Otovo, Selectra, Mr Kilowatt, industry marketplaces). Deductions: Agenzia delle Entrate / 2026 Budget Law. Specs and warranties: Tesla and Huawei. Every system is different: ask us for a tailored quote.
Frequently asked questions
How much does a 5 kWh storage battery cost?
Between €3,000 and €5,500 installed, VAT included, when added to an existing system. Together with a new system it costs significantly less. With the 50% tax deduction the effective cost is halved.
How much does a 10 kWh storage battery cost?
Between €6,500 and €10,000 installed as a retrofit. It's the right size for a family with significant evening consumption, a heat pump or an electric car.
How much does adding storage to an existing system cost?
A retrofit runs about €700–1,100 per kWh, all included. If the battery is installed together with a new system the cost drops to about €400–600 per kWh — nearly half.
How much does an installed Tesla Powerwall 3 cost?
Roughly €7,500–10,500 VAT included for 13.5 kWh: €550–800 per kWh, one of the best price-to-capacity ratios in the premium range.
Does the 50% deduction apply to a battery alone?
Yes: in 2026 the deduction (50% primary residence, 36% other homes) also covers a battery installed on its own onto an existing system, over 10 annual instalments, with a traceable 'talking' bank transfer and the ENEA notification.
