Sep 20, 2024
Rewiring Aotearoa
Electric Avenue: September 20

It's all about the batteries in this week's electrification whip around. Big ones, small ones (but not uncomfortable ones), we love them all and an Aussie legend has developed an affordable way to run our homes with our EVs, a US startup is electrifying school buses and using them to help the grid, Lincoln University rolls out a new electric tractor, Meridian's storage solution is set to power 60,000 homes at peak times (and the company is also set to give away $1.2 million for community electrification projects), and global solar installs continue to exceed industry expectations.

Plug and play

One of the big opportunities with the transition away from fossil fuel vehicles is the role EVs could play as big batteries on wheels. 

There are some EVs that allow what’s called Vehicle to Load (V2L), so you could make a coffee via your MG, make a toastie with your tractor or run a quiet camping generator. So why can’t we plug in and power our homes? 

In Australia, there is only one car, the Nissan Leaf Gen 2, and one charger, the Wallbox bidirectional Quasar, that allow you to do it. But one clever cookie called Ewan Parsons is trying to change that with something called the Hoem device. 

The open-sourced creation complies with 2024 standards and allows for some circuits to be powered by an EV, which is called vehicle to home (V2H). It costs about $900, compared to around $10k for the bi-directional charger, with extra for installation. 

"A typical electric car battery holds about 60+ kilowatt hours of electricity, which is enough to power a small home or apartment for a week," the website says.

As this Solar Quotes story says: “If you can charge at work and come home with a near-full battery every night, you can run the house on the stored sunshine and use the company fuel while avoiding peak evening rates.” 

And you’ll also be in a better position when the grid goes down. 

For more of an explanation on the opportunities and limitations, this video offers a good rundown. 

The energy of youth

While smaller EVs may be able to run your fridge, the big ones could also participate in the electricity market. A startup in the US called Zum is aiming to turn electric school buses into massive grid batteries and hopes to electrify 10,000 school buses over the coming years.

The company has already modernised what it says is the country's biggest mass transportation service - and one it says hadn’t changed for 80 years - with a series of tech advances and it recently announced that Oakland had become the first place to embrace an all-electric bus fleet, with 74 of them on the roads and a charging station in an old industrial lot.  

As this Canary Media story says: "Electric school buses can charge with low-cost power and discharge spare capacity at times of grid stress, when power is both more expensive and more likely to be generated by fossil-fuel-fired power plants.” That’s good for the economics of electric school buses. And it’s also good for the grid.”


“A dream of EV enthusiasts for decades, vehicle-to-grid charging is something for which electric school buses are particularly well suited. Unlike cargo trucks or city buses, they operate only a few hours per day while picking up and dropping off students. That leaves plenty of time for them to plug in and soak up off-peak electricity in the middle of the day — including the surplus solar power that floods California’s grid when it’s sunny out — and discharge it in late afternoons and evenings, when California’s grid faces its most severe imbalance of supply and demand.” 

Diggin' it

Forest Lodge Orchard's electric Monarch tractor gets a lot of traction, in both senses of the word. As the first of its kind in the country, it's been a real novelty, but now it has some welcome company in the form of Lincoln University's own electric tractor.

The new Knegt 404G2E 55HP electric tractor comes from the Netherlands and will be used at the Lincoln University Energy Farm.

"The Energy Farm will comprise a solar array of around 2,800 photovoltaic (PV) panels generating ~2.3 GWh of renewable energy per year. The installation will be the first in Aotearoa to demonstrate high-value agrivoltaics, with the production of premium horticulture crops like blueberries alongside the generation of commercial-scale solar energy. The purchase of the Knegt 404G2E tractor was made possible by the Energy Efficiency and Conservation Authority (EECA) Demonstration Fund, Meridian Energy and Power Turf New Zealand."

Bottle it up

There’s no doubt we’re going to need a lot of batteries to store all the extra renewable electricity we need for our much more efficient electric machines. Big ones, small ones (but not uncomfortable ones). We love them all. 

Meridian is building a big battery in Ruakākā near Whangarei and it is able to pump out 100MW in two hours at peak times, or enough electricity for roughly 60,000 homes. As we’ve seen in places like California, these big batteries can significantly reduce the need for fossil fuel-generated electricity at those times. 

While we’re pro-grid and pro-big batteries at Rewiring Aotearoa, we’re even more jazzed on rooftop solar and household batteries, simply because it reduces the costs for Kiwis and the need for customers to pay for all the upgrades to the poles and wires. 

A recent piece from AUT academics showed the potential for rooftop solar in Auckland, with just 167 schools and supermarkets equivalent to the country’s biggest solar farm. And the same decentralised thinking applies to batteries: “Just 120,000 homes (or 5 percent of households in New Zealand) with a medium-sized battery could potentially reduce the peak load as much as our largest hydro power station, Manapouri. While these batteries would not hold as much energy as Manapouri, they could output the same amount of power for an hour or two when the system really needs it.”

So can we make enough of these batteries? Our recent Watt Now explainer has an answer for that. And so do our friends at Rewiring Australia: “To replace our 250 million personal gasoline--powered vehicles with EVs in the next 20 years, we will need over a trillion batteries, or around 60 billion 18650 batteries every year (18650's are 18 mm in diameter, 65mm long --- slightly larger than your flashlight's AA-size). That is similar to the 90 billion bullets manufactured by the world today. If you need only one statistic to summarize what is wrong with humanity, it is that we only make about 19 billion LEGO bricks every year, yet we make 90 billion bullets --- enough to shoot everyone on earth 11 times a year! Imagine the world where we made 90 billion LEGO's, and cut our bullet consumption back to just a few billion.  We need lots of batteries, but it is possible. We need batteries, not bullets."

Everbody loves the sunshine

According to energy think tank Ember, “the world is on track for another year of record solar growth, surpassing industry projections.” 

“Ember’s analysis of the latest data on monthly capacity installations shows that the world is on track to reach 593 GW of solar installations by the end of this year. This would once again surpass most industry forecasts, and comes after 2023 showed record growth in solar installations of 86% compared to 2022”.

New Zealand has lagged behind on the solar front and when you hear sceptics say we don’t have enough sun, it pays to remember that our solar energy is similar to that of Victoria and quite a lot better than Germany, which both have significant solar resources deployed. 

Money for jam 

While we’re not sold on many of the Certified Renewable Energy Certificate claims, Meridian is handing back a chunk of the money it earns from that scheme to support electrification projects in the community. 

There’s $1.2 million up for grabs through its Decarbonisation Fund so “whether it’s providing funding for a new EV, converting to electric heating, or installing solar power,” community groups have until Sept 30 to put in their request. 

Read moreDownload the document here

More News