Jul 4, 2025
Electric Avenue
Electric Avenue: 4th July

Redwood Materials claims a record with old EV batteries used to store cheap solar to run a small data centre; OneEnergy launches a product that puts the sun directly into your water tank; more plug-in solar news from Ikea and Utah; very fast electric boats and cars; and a beautiful union between two star-crossed lovers.

Old power

Good batteries are important when you’re moving big hunks on metal, but when they’re depleted they are still good for storage and Redwood Materials, the massive battery recycling company started by Tesla  Chief Technology Officer JB Straubel, is claiming a record after it put 792 individual EV battery packs together and produced 63 megawatt hours for a small data centre that was set up alongside. 

The project, outlined in this fascinating Canary Media story, has proven that storage in second-life batteries could be a legitimate business. 

As Straubel said: “This is, in a way, a first of its kind, and to be able to have a profitable project as a first one is pretty cool. You will absolutely see much larger deployments of this in well under a year, and we are actively engineering and working on those projects today.”

Sun on tap

As our research shows, solar and resistive water tanks are a pretty good combo and similar in price over their lifetime to hot water heat pumps. If you’re building new, that’s what we recommend because they are so much more efficient, but One Energy has developed a low-cost option that might appeal to those looking to retrofit an existing system. 

While we also recommend going as big as possible with your solar install as it makes more economic sense to do it all at once, not everyone has the capital, so this $5k option puts six panels up and connects it directly to the water heater. This can reduce electricity bills by between $1000-1200 per year. 

Many people benefited from solar hot water tubes in the past, but as the price of solar panels has dropped, it made more sense to install panels that could power more of your home. 

These smaller systems aren’t grid-tied so you can’t export any excess but it’s designed for self-consumption. If the sun’s not out and the temperature needs a boost, it can tap into the grid for a top-up and then also heat at lower rates over night. Customers can set the timings and retailers can also control it, like a modern version of ripple control. 

It is also possible to add more solar to the roof and connect it to the grid later. We know that solar is a gateway drug to electrification and this could be a good baby step. 

Lots of a little

Speaking of small solar systems, we’ve been following the developments in Europe and the Balkonkraftwerke movement now makes up around 1% of Germany’s significant solar generation. While the plug-in systems only provide a small amount of electricity, it all adds up and the kits are so common now that Ikea has started selling them. 

Utah is the only state in the US to allow it so far and has just made it legal for homes to put up to 1200 watts of solar on their roof or four panels. As this video shows, it’s a fairly simple DIY project. 

We’re working on breaking down some barriers for this kind of technology here in New Zealand and hope to help drive demand among renters and apartment dwellers. As electricity prices continue to increase, any reduction in price should be welcomed. 

Speed-E 

We’ve seen a few impressive electric boats in New Zealand recently from the likes of Vessev, Naut and EV Maritime. And the electric raceboats that took to the water on the Thames recently also turned a few heads. 

They were there to promote a racing series called E1. And the boats clearly showed that the electric future is fast. 

While the electric Formula E series isn’t yet as popular as F1, it did have record breaking viewership last year and more manufacturers are getting involved. It claims to be the world’s fastest growing motorsport. 

Even at Nascar, they have a plan to go electric by 2035 and have released a few prototypes alongside its sponsor ABB.

A marriage of convenience 

Solar and batteries are a match made in heaven and, as Australia’s battery subsidy kicked in on July 1, Solar Citizens celebrated with a video showing the new power couple committing to each other. 

How about a honeymoon in New Zealand?

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