What does battery storage actually cost?

Last updated: 3 July 2026 · Written by the ECONEXIS team, MCS-accredited installers.

Battery prices have fallen far enough that we now include storage in almost every system we design. Here's what batteries genuinely cost in 2026, using our own recent quotes rather than internet averages.

Real solar + battery package prices

• 10 panels + 5 kWh battery — from £6,690 installed.
• 10 panels + 10 kWh battery — £7,990 installed.
• 12–14 panels + 11.5 kWh (Fox ESS) — around £8,300–£8,900 in recent quotes.
• 14–17 panels + 23 kWh (Fox ESS) — around £10,300–£11,800.
• 15–20 panels + 17.5 kWh (Sigenergy) — around £13,400–£14,000.

All prices include installation, certification and the DNO application, at 0% VAT. Your exact figure depends on your roof and usage — every system is custom-designed, and your free design is usually back within 24 hours.

What size battery do you actually need?

Bigger isn't automatically better — an oversized battery you never fill is wasted money. As a rule of thumb: a typical family evening uses 5–10 kWh, so a 10–12 kWh battery covers most homes; heavy users, EV owners and anyone planning a heat pump benefit from 17–23 kWh. We size storage from your actual usage pattern, not a guess.

Which brands we fit — and why

We install Fox ESS (outstanding value, our most-fitted brand), Sigenergy (modular — grows with you) and Tesla Powerwall 3 (the premium ecosystem choice). Our side-by-side brand comparison covers the differences honestly. All carry 10-year warranties and are backed by our insurance-backed workmanship guarantee.

How a battery changes the maths

Solar without storage typically covers 35–50% of a home's usage, because generation peaks at midday while usage peaks in the evening. Add a battery and self-use jumps dramatically — evenings run on your own stored solar. Across our recent quotes, battery systems produced estimated first-year savings of £1,100–£2,100 with payback of 5–8 years. A battery can also charge from cheap overnight tariffs in winter, saving money even when the sun doesn't show up — see how solar and batteries perform in winter.

Adding a battery to existing solar

Already have panels? A retrofit battery is a straightforward job and is also 0%-VAT eligible. Prices depend on capacity and your existing inverter setup — tell us what you have and we'll quote it exactly, free.

Get my free custom quote