Energy storage start-up, Powervault has exceeded its £350,000 crowd funding target as it looks to commercialise its ‘plug and play’ domestic storage device.

The London-based company has now raised almost £400,000 from a total of 160 separate investors, having originally aimed to raise £150,000. Its first funding round launched in September last year, closed in just eight hours.

The company is now seeking to “overfund” the target, meaning it will now attempt to top the total up to £500,000 over the last remaining few days of its campaign, according to a company spokesman who contacted Solar Power Portal. The spokesman said this practise is typical for the Crowdcube crowdfunding site, on which the campaign is hosted.

The patent-pending Powervault device claims to store energy generated from rooftop solar panels during the day for consumption at peak evening times, promising to cut up to 15% off household electricity bills.

An integrated battery and control system is used and the storage device can be plugged into a standard 13 amp power outlet to charge, while the company also claims the system can be simply retrofitted to existing solar systems by a professional installer.

“In short, Powervault solves two problems for solar PV owners: using free solar energy when the sun isn’t shining and providing the option of emergency power supply during electricity blackouts,” Joe Warren, managing director at Powervault, said.

Kent-based Greenman Solar is the first domestic installer to offer the solution as an add-on to its products and Niko Miaoulis, managing director at Greenman Solar, said the firm had a waiting list of customers who had expressed an interest in the product.

The product received support from Imperial College’s Climate-KIC accelerator programme, which supports innovations aimed at tackling and mitigating the effects of climate change.

This story has been update from its original form to clarify that the Powervault crowdfunding campaign is not yet closed, although the initial target was reached.