Battery technology has advanced to the point where commercial systems are hitting the market and electric vehicles themselves could double as grid storage devices. Mathew Beech reports.

The time is now for investment.” This is the view of Joe Warren, chief executive of Powervault, one of the many energy storage companies thriving on the crest of a wave of activity in the nascent sector.

After being talked of for years as a significant technology for the future of the electricity system, we are now at a point where energy storage – at all scales from domestic up to industrial and grid – has arrived. Major international brands – such as Nissan and Tesla – are getting involved, along with Eon and British start-ups Moixa and Powervault.

In addition to rapidly declining technology costs (lithium ion batteries typically cost around $200/kWh today compared with $3,000/kWh in 1990), a key driving force behind this surge in development is the imminent arrival of smart metering and the promise of time-of-use tariffs.

David Holmes, managing director of the Quarry Battery Company, estimates that Britain could cut the cost of decarbonising its electricity supply by £3.5 billion a year with grid-scale electricity storage to balance intermittent renewables. If technology costs continue to fall and investment continues to stream into energy storage, the National Infrastructure Commission has said that 15,000MW of energy storage could feasibly be deployed in the UK by 2030, kick-starting this momentous energy system transition.

Among the most notable recent energy storage announcements is the news that the leading manufacturer and seller of electric vehicles (EVs) Nissan – it has sold more than 200,000 since 2010 – has turned its attention to storage.

The Japanese company has partnered with power management firm Eaton (see box, below) to develop the xStorage device, which reuses old EV batteries for domestic energy storage. Nissan also has plans to turn its EVs into “mobile storage”, whereby vehicles help to balance the grid (see “Using EVs to offer backup storage to the grid”, right).

Nissan joins Tesla as an automotive big hitter revealing aspirations in the energy storage market. Tesla unveiled its Powerwall storage device last year and says  it had orders for 38,000 devices in the first week

Closer to home, Powervault has unveiled the second generation of its household storage device in preparation for the smart revolution. The company launched its third equity round last month, aiming to raise £1 million and to sell 50,000 units by 2020 in the UK. The company tells Utility Week it is now working on a project with Nissan and no doubt we can expect news of many more alliances, acquisitions and strategic partnerships in coming months, as those with big ambitions in the storage market seek to position themselves to advantage.

These alliances will not only be in the domestic energy storage market. At the bigger end of the storage game, Eon and RedT are already working together to trial a larger-scale storage system at the headquarters of warehousing and logistics company JB Wheaton in Somerset, as part of a bid to understand the potential for improved payback on solar PV installations.

In the utility-scale storage arena, solutions being tested in distribution network innovation projects – like UK Power Networks’ (UKPN’s) Leighton Buzzard scheme – will find themselves head to head with solutions from the likes of Tesla, which has announced plans to deploy super-sized Powerwall devices in the Republic of Ireland.

It is still uncertain whether distribution network operators will be able to participate directly in this dynamic new marketplace, but on the back of results from the Leighton Buzzard trial UKPN reported that “not only can battery storage be used in multiple applications but, commercially, it should be”.

A consultation by Ofgem and the Department of Energy and Climate change on regulatory barriers to storage deployment, including the ability of distribution companies to own and operate storage, is currently ongoing and will issue a definitive list of reforms in the spring of 2017. But with juggernauts like Nissan, Eon and Tesla weighing into the market, as well as increasing amounts of venture capital pouring into entrepreneurs such as Moixa and Powervault, market forces are clearly building a head of steam. It is now almost certain that we can expect energy storage to become a business as usual feature of the energy system very soon. 

Some of the latest storage solutions on offer:

1.    Nissan xStorage

Japanese car manufacturer Nissan has teamed up with power management company Eaton to launch its xStorage battery storage unit, which will also form a central part of its vehicle-to-grid (V2G) solution (see box, right).

The 4.2kWh unit will cost consumers £3,200 and it is being touted as the most affordable domestic energy storage solution on the market. Nissan and Eaton expect to sell 100,000 xStorage units in the next five years.

2.    Powervault

Domestic energy storage company Powervault recently launched the second generation of its energy storage system (see main copy, above). The systems are equipped with an emergency power socket to keep essential equipment running in the event of a blackout.

3.    Tesla

Tesla founder Elon Musk sparked wider interest in the energy storage sector when he revealed last year his company was launching the Powerwall battery storage device. It comes in 7kWh and 10kWh forms and the rechargeable lithium-ion batteries are designed to collect and store excess energy from roof-mounted solar panels.

4.    Moixa

Moixa is in the midst of a £1.5 million pilot project for Decc in which it will install and test 250 energy storage units to demonstrate how storage can benefit customers and networks.

At the end of last year, it also launched the Maslow GridShare platform so residential energy storage can be aggregated, allowing network operators to more easily balance supply and demand.

Non-domestic storage

The storage revolution is also taking hold in the non-domestic sector. Eon has begun a research project in Somerset with a logistics company to understand how storage can work with the 5kW/40kWh solar PV system currently installed.

It aims to smooth out the peaks and troughs of the output of the PV panels, provide energy to charge the company’s vehicles overnight, and minimise the energy taken from the grid at periods of high prices.

Eon is working with energy storage business RedT, which has plans to install 19 seeding units into commercial properties globally.

It is not the only player in the large energy storage arena. Camborne Energy Storage, fresh from agreeing two new partnerships, is keen to rollout solutions to grid, distribution systems and large-scale energy users.

Large-scale storage is already being tested – and UK Power Networks is heading into the final six months of its smart energy storage trial in Leighton Buzzard. The core trials have already been completed and revealed that battery storage “can be used in multiple applications in order to make it more commercially viable”.

The key in this area is overcoming the regulatory barriers and allowing the technology to be used for multiple applications, and therefore have multiple income streams, to allow it to be more widely developed across the UK.

Using EVs to offer backup storage to the grid

Japanese automotive giant Nissan has unveiled plans to connect 100 vehicle-to-grid (V2G) units across the UK in the first ever trial of electric vehicles as mobile energy storage.

Nissan will place the V2G units at locations across the country agreed to by private and fleet owners of the Nissan Leaf and e-NV200 electric van, giving them the opportunity to plug in their vehicles and sell energy stored in their vehicle battery back to the system.

If all Nissan EVs in the UK were connected to the grid, they would generate the equivalent output of 180MW, helping to balance the grid in the process.