Home Battery Storage: Complete Buyer's Guide 2026

How Does Home Battery Storage Work?

A home battery stores electricity for later use. Most homeowners use a battery to store surplus solar panel generation during the day, then use that stored electricity in the evening — avoiding paying grid rates of 24.67p/kWh.

Even without solar, batteries can charge on cheap overnight electricity (some tariffs offer 7p/kWh at night) and discharge during expensive peak periods. The savings are smaller than with solar, but the payback case still exists on the right tariff.

Is a Battery Worth It Without Solar?

Without solar panels, a battery's value depends entirely on your energy tariff. With a time-of-use tariff (such as Octopus Go or EDF GoElectric), you can charge at off-peak rates (7–10p/kWh) and avoid using grid electricity during peak hours (24.67p/kWh).

A 10 kWh battery saving 8 cycles per week of off-peak charging could save £400–£600 per year on the right tariff. That gives a payback of around 8–10 years on a typical battery installation. Add solar panels and the savings jump to £900–£1,400+ per year, shortening payback to 5–7 years.

Foxstar vs Tesla Powerwall vs SIG Energy

These three brands cover the majority of home battery installations in the UK:

• Foxstar — UK-based manufacturer, excellent local support, wide range from 5 kWh to 19.9 kWh, strong software via Foxstar app. Best value for most homeowners.
• Tesla Powerwall 3 — Premium brand recognition, integrated inverter in Powerwall 3, 13.5 kWh capacity. Higher cost but excellent build quality and backup power capability.
• SIG Energy — Competitive pricing, modular design, well-regarded in the installer community. Good option if cost per kWh is the priority.

For a detailed head-to-head, read our Foxstar vs Tesla Powerwall comparison.

How Much Does a Home Battery Cost?

A typical home battery installation costs:

• 5 kWh battery: £3,000–£4,500 installed
• 9.5 kWh battery: £4,500–£7,000 installed
• 13.5 kWh (Tesla Powerwall 3): £7,500–£11,500 installed

Prices vary based on the installation complexity, any required electrical upgrades, and whether the battery is being retrofitted to an existing system or installed with new solar panels. Pairing solar and battery together in one installation often saves money compared to fitting them separately. See our solar and battery cost guide.

VAT Rules on Battery Storage

From February 2024, standalone battery storage systems qualify for 0% VAT on residential installations in the UK, regardless of whether solar panels are fitted. This change significantly improved the economics of battery-only installations and means the prices above already reflect the 0% VAT rate.

Payback and Savings

Expected annual savings from a 9–10 kWh battery with solar panels: £350–£600 per year from reduced grid imports. Combined with solar panel savings of £700–£1,000 per year, the total system saves £1,050–£1,600 per year.

Payback period for a solar and battery system together: typically 6–9 years, after which the system generates pure savings for the remaining 15+ years of its life.

Getting a Battery Installed in Cornwall

We install Foxstar, SIG Energy, and Tesla Powerwall batteries across Cornwall, including Truro, Newquay, St Austell, Bodmin, and all surrounding areas. Book a free survey to discuss whether battery storage is right for your home.