Using recycled Nissan Leaf batteries, Counties Energy deploys 240 kWh of stored electricity in Mercer

Let's be honest: big batteries aren't very visually interesting, even when encased in nicely painted cabinets. They just stand there, filled up with electric energy in the bone-chilling mist covering Mercer, which is the location Counties Energy and its design partner from Melbourne, Relectrify, had picked to launch a recycled large capacity battery initiative. 

Counties Energy said this is a first for New Zealand. Moonis Vegdani, the power company's chief strategy and transformation officer, explained the Berm Battery system went into the Mercer Service Centre as there were capacity issues with the transformer at the location. The service centre hosts two of Counties Energy's OpenLoop rapid EV chargers. Without the Relectrify battery, charging was limited to 120 kilowatt; battery-backed, it goes up to 180 kW.

What's interesting here is not so much the improved charging performance, but the way batteries can create a new stored electric energy distribution system. Economically too: Relectrify vice-president Jürgen Barth estimated a network upgrade with new transformer would cost $2 million to $3 million, but their battery cabinets are about $75,000 each. 

Counties Energy said that wasn't the cost for them, as they had to ship the cabinets, assemble, commission, test, certify them locally before installing the system on the site. How much exactly that cost was not revealed.

There are two Relectrify designed Revolve cabinets at the Mercer Service Centre. Each contains nine batteries repurposed from Nissan Leaf electric cars, each of which had 24 kilowatt hours capacity when they were fresh out of the factory from 2010 onwards. Now, they have around 70% capacity left which is interestingly enough much better than expected, Vegdanis said. Rapid battery degradation has long been a bogeyman for EVs, but the reality is that they tend to endure longer than initial pessimistic estimates, and often last for the life of the vehicle.

Inside of the Relectrify cabinet with Nissan Leaf batteries

Vegdanis pointed out that reusing batteries after they've done their duty in cars means they'll live on for another eight to 15 years. Having an energy store with a service life of 25 years or more is pretty impressive.

Total capacity for the Mercer system is 240 kWh, and the Nissan batteries are connected with Relectrify's Cellswitch technology. This manages each individual cell separately to increase utilisation and throughput.

The cabinets in Mercer weigh about three tonnes each. Barth said that Relectrify has other designs in the works that are lighter and towable at 1.8 to 2.5 tonnes, which could come in handy for EV charging at events, for example. Vegdanis meanwhile is thinking big, and talked about container-sized models for charging freight company truck fleets.

There's no large scale EV battery recycling scheme in New Zealand as of yet (it's in the works); despite the market for EVs taking a coalition government-induced breather currently, there are around 75,000 electric cars in the country already. Being able to repurpose EV batteries for other uses be it backup power, resilience, keeping mobile phone sites alive, and more, does seem more sensible than finding a spare landfill site for them.

Minister Andrew Bayly, MP for Port Waikato, Counties Energy chief executive Judy Nicholl and Waikato District mayor Jacqui Church tripling up to demonstrate EV charging in Mercer.

How far the recycled EV battery concept will extend probably depends on if second-hand energy stores other than the 24 kWh ones in Nissan Leafs can be used in the same fashion.

Counties Energy chief executive Judy Nicholl said they're taking the Berm Battery concept down to Palmerston North next.

The above seems very thoughtful and sensible, futuristic even. Head back to Auckland though and reality hits you hard after the Bombay Hills where you're caught in stop-and-go traffic for kilometres on end. This is courtesy of interminable roadworks. Although well-managed, there are just too many cars so the motorway clogs up. Mostly older fossil fuel vehicles like the one your faithful technology correspondent drives, generating kilograms worth of tailpipe emissions while moving at a snail's pace. 

Imagine how many cars a train could remove from the motorway, which eats up so much of the flat and fertile land in the area. It could even be battery-backed rail perhaps. The decarbonised future. We don't really live in it yet.