Renault and Powervault have announced a partnership to re-use electric vehicle (EV) batteries in home energy storage units. This partnership is expected to reduce the cost of a Powervault smart battery unit by 30 per cent, helping Powervault to bring home energy storage to the tipping point of mass-market roll-out in the UK.

Powervault is placing 50 trial units, powered by second life batteries provided by Renault, in the homes of customers who already have solar panels installed. The trial will explore the technical performance of second life batteries as well as customer reaction to home energy storage to help develop a roll-out strategy for the mass-market. The trial will be run with eligible customers of M&S Energy, plus social housing tenants and schools in the South East.

Powervault is a home battery system, which enables homeowners to store and use the solar energy freely-generated from their own solar panels. Powervault units can also automatically charge using low cost, off-peak energy from the grid. The Powervault system sits at the heart of the smart home and the optimisation of energy usage within it. As well as reducing the cost of production of a Powervault, the use of second life batteries will also optimize the life-cycle of the Renault batteries before they are recycled.

Joe Warren, Managing Director of 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. 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.”

Nicolas Schottey, Program Director, EV batteries and infrastructures at Renault, said: “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. The second life use not only gives additional life to electric vehicle batteries before they are recycled, but also allow consumers to save money. It’s a win-win-win: for EV owners, home-owners and the planet.”

Renault contributes to the energy transition through the re-use of its EV batteries for stationary energy storage. The batteries used in electric vehicles usually have a lifetime of 8 to 10 years. However, there is still plenty of useful life in these batteries for stationary applications; giving the batteries an additional life before they are recycled. Within a Powervault home battery system, Renault batteries are estimated to have up to 10 years of additional useful life. Second life battery packs are removed from the electric vehicles, unpacked and graded before Powervault make them into smaller battery packs for their application.

Jonathan Hazeldine, Head of M&S Energy, comments: “We know M&S customers share our vision of caring for our planet and building a more sustainable future. At M&S Energy, the biggest impact we can have on this is by sourcing energy responsibly and by helping our customers use it as efficiently as possible. We have been supplying 100% green electricity since 2015 and initiatives such as our Community Energy Fund are helping our communities become more environmentally and financially sustainable. With the Powervault trial, we now have a great opportunity to help our customers reduce their impact, and ultimately their energy bills, by understanding how we can make smart energy storage work for them.”

The Powervault second life trial will start in July 2017 and last 12 months.