Reference / Battery / Overview
Battery storage
A battery is the most expensive single decision in the stack and the one with the slipperiest payback. Capacity matters less than the shape of your day.
Before you start: the case for a home battery depends almost entirely on your tariff and your evening load shape. We recommend reading our long-form essay on the topic before any quote conversation.
Sizing
The right capacity is the one that captures most of your shiftable energy without leaving large unused headroom. For most UK semi-detached houses this lands between 5 and 10 kWh. Sales-led conversations often suggest larger.
Chemistry
Lithium iron phosphate (LFP) is the right answer for almost every UK domestic installation. It is safer, less energy-dense (which matters less when the battery lives on a wall) and longer-lived than nickel-manganese-cobalt (NMC) alternatives.
Hybrid systems
All-in-one hybrid inverters fold the solar inverter and battery management into a single box. The trade-off is tidiness against a single point of failure.
Payback
Modelled payback depends on whether you treat the battery as a self-consumption device, a tariff-arbitrage device, or both. The wider definition usually gets to a sensible number; the narrow one rarely does.
Virtual power plants New
VPPs let your battery earn small amounts during grid stress events. The Octopus Tesla Energy Plan is the established UK option. Several smaller schemes are running in 2026 with varying degrees of polish.