French automaker Renault has partnered with UK energy storage firm Powervault to reuse batteries from electric vehicles in home energy storage products.

The move will see the cost of a lithium battery-based Powervault home storage unit drop by 30 per cent to around £3,000 fully installed, which it says will help bring energy storage to the "tipping point" of mass market rollout.

Nicolas Schottey, programme directorof EV batteries and infrastructures at Renault, said it is the latest branch of Renault's emerging strategy to maximise the use of its battery packs. "Thanks to this home energy storage partnership with Powervault, Renault is adding a new element into its global strategy for second life batteries, which already covers a large number of usages from industrial to residential building and districts," he said.

Powervault also announced a 12-month trial of 50 units in homes fitted with solar panels across the UK, to assess the technical performance of the batteries and gauge consumer response to home energy storage. The trial will be a mix of M&S Energy customers, social housing tenants and schools in the South East, Powervault said.  

"The collaboration we are announcing today with these two household name brands – Renault and M&S – is an important milestone on our journey towards achieving mainstream adoption of home energy storage," Powervault managing director Joe Warren said. "Homeowners and brands are now looking to benefit from the smart power revolution.  It's only a matter of time before a Powervault becomes as common in [UK] households as a dishwasher."

For Renault, the move follows in the footsteps of fellow carmarkers BMW and Nissan, which have both in recent months announced ‘second-life' storage schemes in partnership with energy storage companies.

Not only will the sale of second-life batteries prove another revenue stream for car companies, it also helps alleviate the issue of dealing with millions of tired battery packs from older EVs.

"The second life use not only gives additional life to electric vehicle batteries before they are recycled, but also allow consumers to save money," Schottey said. "It's a win-win-win: for EV owners, home-owners and the planet."

Most experts expect home storage systems will prove initially popular with PV-owning households, with others following later once the costs come down.

According to Renault, the batteries used will be around 10 years old, and will have a further 10 years of additional life in them as part of a Powervault system. Powervault said it expects to sell 30,000 of the Renault units by 2020 – equal to 15,000 car batteries.