Solar Battery Storage — Cut Your Grid Reliance to Near Zero

A standalone home battery system costs between £2,500 and £8,000 installed, depending on capacity and brand. A 9.5kWh Tesla Powerwall 3 installed costs approximately £8,000–£10,000 including hardware and installation. GivEnergy 9.5kWh systems typically range from £4,500–£6,500 installed. If combined with a new solar panel installation, some installers offer bundled pricing with reduced labour costs.

The three market leaders in the UK are Tesla Powerwall 3 (13.5kWh, integrated inverter, premium build quality), GivEnergy (5–19.9kWh modular, AC or DC-coupled, best value), and Solis/Sofar (budget-friendly, widely available). For new solar installations, DC-coupled batteries (connected before the inverter) are 5–8% more efficient than AC-coupled retrofits. GivEnergy offers the best balance of capacity, reliability, and cost for most UK homeowners.

A Distribution Network Operator (DNO) application is required for battery systems over 3.68kW export capacity. In practice, most home battery systems trigger a G98 or G99 notification to your local network operator. Your MCS-certified installer handles this paperwork — it's not your responsibility. Failure to notify your DNO is a building regulations breach, so always use a registered installer.

Yes. Retrofitting battery storage to an existing solar installation is straightforward using an AC-coupled system — meaning no changes to your existing solar inverter or panels. The battery connects to your household AC circuit and charges from the grid or solar. If your existing inverter is compatible (most modern inverters are), a DC-coupled retrofit may also be possible, offering slightly better efficiency.

Winter performance depends on battery temperature and available solar generation. Modern lithium iron phosphate (LFP) batteries, used by GivEnergy, perform reliably down to -10°C. Tesla Powerwall uses lithium NMC chemistry with thermal management. In a UK January, a south-facing 4kWp system generates 200–350kWh — roughly a quarter of summer output. A 9.5kWh battery will fill from solar on brighter winter days (3–5 hours of usable generation) and can be scheduled to charge from cheap overnight grid tariffs (e.g., Octopus Intelligent at 7p/kWh) as a backup.

From 1 February 2024, standalone battery storage systems (not combined with solar) attract 0% VAT when installed in a residential property. Previously, only batteries installed alongside solar panels received this relief. This represents a saving of approximately £500–£1,600 depending on system size.