Nov 22, 2024
Rewiring Aotearoa
Electric Avenue: Nov 22

A big week in the long-running battle to turn EVs into batteries on wheels, researchers prove that using cheap solar during the day to heat the water is a good idea for customers and the grid, a solar map of New Zealand that offers lot more detail, tiny turbines (and tiny homes inside massive turbines) and a flood resistant EV.

Driving it home

It’s long been a dream of EV enthusiasts for electric cars to power our homes and contribute to the grid, not just move us around and it looks like that will soon become a reality in Australia as Vehicle-to-grid (V2G) charging crossed an important regulatory hurdle this week. 

This excellent ABC story runs through some of the barriers the technology has faced and the likely roll out of bi-drectional chargers that allow the transfer of electricity and, as it summarises:  

In short:
Vehicle-to-grid (V2G) charging, where electric vehicles can be used to power households and export energy to the grid, has cleared an important regulatory hurdle.
The federal government says the first V2G chargers will be certified by Christmas, but industry experts say a more likely timeline is mid-2025.

What's next?
The mass uptake of V2G could reduce household energy spending and also defer the need for some big energy storage projects, but it's unclear which EV models currently on the market in Australia will support V2G next year. 

New Zealand is currently looking to Australia and other trading partners to update over 400 outdated standards around solar installation and EV charging, as well as consulting on the voltage range. We’re confident it won’t be too long before this is available in New Zealand, and many of the newer EVs already come equipped with the tech required to do it.  

As Saul Griffith said during his Investing in Tomorrow tour

🚗🔋 All the electric vehicles in New Zealand will be one of the country's biggest batteries.

☀️🔌 All the rooftop solar on our homes and farms will be one of the country's biggest generators.

🏭 And, just as the hydro dams and transmission lines of the 20th Century got good deals on finance because they were seen as critical infrastructure, this growing collection of 21st Century customer assets needs to be seen as critical infrastructure, too. 

As the cost of grid electricity keeps going and power bills rise next year to pay for the upgrades of our poles and wires, new technology allows savvy customers to offset some of those costs, either by producing your own or getting involved in the electricity market. This is a world we’re working towards and it will be a better world for customers.

Liquid assets

We like to do our own research at Rewiring Aotearoa (not in that way) but we also like it when others do research that backs up our view and in a real-world trial in Australia, academics have looked at whether using cheap rooftop solar during the day to heat water is a good idea. 

The headline says it all, really: “If our hot water heaters ran off daytime solar, we would slash emissions and soak up cheap energy”.

“Switching water heaters to charge during the day can soak up solar power going to waste – known as curtailment – and make sure electricity supply and demand match. In our new real world trial, we put this technique to the test and found it works.” 
“... As ever more renewables enter the grid and more Australian households go electric, many of us will ditch gas hot water systems. These trends mean heating water during the day will be even more valuable.”

In New Zealand, our Electric Homes report showed that heating water (which makes up around 30% of a home's energy use, not including vehicles) is cheap as chips with solar and a heat pump.

Drilling down (on solar)

Some more interesting research into solar, with Yvonne Matthews “using advanced machine learning techniques on aerial imagery to detect where solar panels have been installed in New Zealand and provide much more detailed information than the aggregated data available the EA

As she discovered: 

  • Solar potential: Solar potential is NOT a strong predictor of where household solar is installed, at least within the ranges of this data.
  • Wealth and Property Characteristics: Solar panels are more common on larger, newer homes with steel roofs and above-average capital values.
  • Building Type and Density: Multi-unit dwellings are less likely to have solar panels, and adoption patterns vary with urban density. Semi-rural properties tend to have lower adoption rates, after controlling for size and improved value.
  • Spatial Influence: Solar adoption shows significant spatial correlation, suggesting that solar uptake in one area might influence neighbouring areas, or there are unobserved local factors involved. For example, solar adoption in Cambridge is above average even outside the subdivision where it is required by covenant.

This last one is what’s known as the neighbourhood effect and, as Mike Casey outlined in his latest opinion piece, “generally, we hang on to old ideas for a long time, and it basically takes someone's neighbour to do something before they adjust their views on it.”

Shoot the breeze

We talk a lot about rooftop solar, mostly because it’s the cheapest form of electricity available to New Zealand households, and how it's very different to solar farms because the delivery costs and middlemen fees are removed. So what about wind? Can we also go from just a few massive turbines to lots of small turbines? 

The company behind Aeroleaf reckons it’s possible and has developed a turbine that looks like a curled leaf and are installed in groups called a ‘wind tree’ or ‘wind bush’. 

“When the wind blows, it spins and generates energy that can go directly to a nearby building,” says Luc Eric Krief, CEO of a French startup called New World Wind.

Pretty clever, but, as always, it all comes down to cost. And in many cases it’s probably cheaper to get solar and a battery. 

One unexpected benefit of going big is that an old turbine can be turned into a home.

Rise of the aquacar?

Sick of driving your EV on the roads? Chinese auto company BYD has you covered with the 'flood resistant' plug-in hybrid U8, which it has launched under the luxury sub-brand Yangwang.

It could be argued that modern cars are over-engineered but, as some have pointed out, floods are likely to be a more common occurrence in our hot world. 

In case water resistance isn’t the main driver in your car purchasing decisions, it also has a range of other features and shows how far the Chinese EV manufacturing industry has come. 

Just like flying cars, while the idea of amphibious vehicles has always been appealing, they have never really delivered. 

Sorry, Aquada. 

Read moreDownload the document here

More News