Powervault launches P4 fourth-generation battery storage system

Powervault unveiled the P4, its fourth-generation battery storage system, during Futurebuild, the company said on 24 March 2023¹. The maker describes it as its most powerful system for homes and commercial buildings, with a larger battery and inverter than the PVCompact¹.

Customers can choose from five AC capacities: 8kWh, 12kWh, 16kWh, 20kWh and 24kWh¹. Each model is compatible with solar PV and wind turbine systems and is enclosed in a slim, all-in-one, wall-mounted design¹. Powervault says the modular approach lets installers gradually increase capacity later, so homes and businesses can expand without replacing the entire system¹. The company also offers emergency power supply options, which it says keep the lights on during outages¹.

The system runs on Powervault's SmartSTOR software, which the company says optimises the device daily according to the customer's tariff, power use and weather predictions¹. Powervault states that existing solar users often sell much of their generated energy back to the grid at a low price, and that with the P4 they could see their generation utilisation double while maximising savings from a time-of-use tariff¹. Users can monitor charging, discharging, solar generation and energy usage through Powervault's online portal¹.

"It's a pivotal year for battery and energy storage deployment in the UK, so we're delighted to launch the Powervault P4, our most advanced energy storage system. Domestic and commercial customers alike are deeply concerned about energy security and costs. Storage systems, especially those co-located with renewable generation, are increasingly becoming one of the most sought after ways to tackle those concerns while making positive strides to combat climate breakdown."

Powervault says it is one of the few manufacturers providing post-installation customer support, becoming the customer's primary point of contact for operational support after fitting¹. The company announced a £3.8 million equity investment round in February 2023, which triggered conversion of £3.1 million in Loan Notes raised in 2020 under the British Business Bank's Future Fund structure². No installed price for the P4, warranty terms or efficiency figures appear in the published material¹.

Why it matters for households

A battery of this size class changes what a home can do with its own generation. Storing surplus solar for evening use, rather than exporting it at low rates, is the core proposition Powervault makes for the P4¹. The modular design matters for households that expect their needs to change, for example after buying an electric vehicle, because capacity can be added rather than the whole unit replaced¹. For homes already generating, adding battery storage to a solar system is the route Powervault describes, and the P4 is compatible with wind turbines as well as solar¹.

Backup power is the other household-facing feature. Powervault says emergency power supply options are available, but the published announcement does not state which circuits stay live, how long a given capacity would last, or what hardware is required¹. Households weighing outage protection against cost will find those details absent from the launch material. The Powervault manufacturer page and the wider home batteries section cover how these systems are typically configured.

What happens next

No UK availability date, pricing or installer rollout schedule for the P4 is given in the published announcement¹. Powervault's news index lists later developments, including a government decision to exempt retrofitted battery energy storage systems from 20% VAT effective 1 February 2024, a customer app launched at Solar & Storage Live 2025, and a flexibility solution with Voltalis announced in September 2025².

Sources2 cited

1. AI-powered home energy storage system hits the market • Powervault, powervault.co.uk
2. News & Updates | Powervault • Powervault, powervault.co.uk