It's estimated that if 30% of New Zealand cars were electric, their vehicle to grid output would be the equivalent to all of our power stations running at full power combined. After many discussions and lots of research, Rewiring Aotearoa has recognised that it is not the regulations or the system holding what’s known as vehicle-to-everything (V2X) back here. Bidirectional chargers can be installed in New Zealand and Rewiring Aotearoa has confirmation from at least one EDB that no additional approvals are needed to export, though some vehicle-to-grid (V2G) will need this, like if it’s not part of a system that already exports or doesn’t have the right spec inverter etc.

The main blockage appears to be from car manufacturers that have yet to unlock the capability here, even if it has been unlocked elsewhere. We understand some manufacturers can unlock it for specific cars if a request is made and we’re expecting some announcements in the next quarter from other big manufacturers. 

According to energy expert Jonathan Holmes, vehicles with CCS charging (which is the most common form in modern EVs) use the ISO15118-2 standard for charging and can be ‘made’ to do V2G with a software bypass firmware upgrade on the V2G charger. This may have an impact on warranties. Newer vehicles compliant with ISO15118-20 will do V2G natively along with many other benefits (if the manufacturer unlocks it). 

Specific chargers are required to make use of the car’s large battery and the ones that have been available up until now have been very expensive. But bidirectional chargers from Sigenergy that can charge at up to 25kW have been approved in New Zealand and the company released a video saying it has enabled V2X on its app (Beauden Barrett has one of the chargers in his house), while StarCharge, one of the world’s largest charger manufacturers, officially launched its Halo V2G bidirectional charger in Australia recently and it is thought these will soon be available in New Zealand. 

Nissan and Mitsubishi have unlocked the capability on their cars and the huge number of cheap Nissan Leafs helping out around the home could be a particularly good thing for low-income households, but very early Gen 1 Nissan Leafs can’t do V2X. Plug-in hybrids have relatively small batteries and it is challenging to get CHAdeMO V2G chargers in New Zealand. 

While V2X is not here in a big way yet, it’s getting closer, there are no real technical or regulatory barriers in the way, and it’s yet another reason to upgrade your fossil fuel car to an EV when the time comes because there's an opportunity to create a new revenue stream and that will lead to faster payback.

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Technology like vehicle to home (V2H) or vehicle to grid (V2G) turns EVs from what many believe is a problem (‘the grid won’t be able to handle all this extra charging load’, which is BS, by the way) into a resource (‘batteries in cars could help smooth the peaks on the grid and power their home or their neighbours’ home and provide weeks of resilience in a natural disaster'). It's estimated that if 30% of New Zealand cars were electric, their vehicle to grid output would be the equivalent to all of our power stations running at full power combined.

Electric vehicles already make economic sense because they are so much cheaper to run, but they also offer new opportunities. For example, someone installing a Tesla home battery today might pay about $15,000 for a 13.5 kWh battery, or about $1,100 per kWh of storage. In comparison, you can get a BYD Atto 3 with a 50kWh battery for about $50,000. In other words, it's a cheaper battery - that comes with a free car! The same is true of a $5,000 second hand Nissan Leaf. While this is the case technically, to date there have not been practically available V2G chargers other than a few test cases.

V2G chargers are relatively new to market, but more options are becoming available and prices continue to decrease. It’s also important to note that a battery by itself often still makes economic sense and provides home resilience when a vehicle is not parked, but the point to be made is that we are about to get a lot of energy storage that can help with the grid and can reduce the need for gas and coal fired electricity production - and it’s going to come free with our cars. A petrol tank doesn’t do that.

Some EVs can already run appliances (what’s known as Vehicle to Load). For example, you can already charge your laptop or run a fridge with some models, but these big batteries could be doing much more than that. A recent paper in Nature suggested “V2G can provide short-term storage when EVs sit idle, which is the case for over 90% of the time for privately owned cars. The technical feasibility of V2G has been demonstrated in over 100 pilot projects since 2002.”’

Smart bi-directional chargers are able to distribute energy to the home or the grid when required (or stop charging if there is too much pressure on the network). Customers can also set limits via apps, so they can benefit from supplying energy to the market from their car but always maintain a minimum amount of charge so it is always ready to go. 

Australia is a fair way down this path and there is currently a national roadmap being created for V2G that will hopefully be implemented in New Zealand given the Government has said it would match standards across the ditch. With 1.5 million EVs expected to be on Australian roads by 2030, it is estimated that just 10% of them with V2G capability could meet around one third of the National Energy Market's total storage needs.

‍A trial in Baltimore using Ford F-150 Lightning utes, which come with a ‘back-up mode’ that can power homes that have extra kit installed, paid owners to take pressure off the grid. 

“EV owners simply plug in their trucks, and they automatically discharge to cover home energy usage between 5:00 and 9:00 p.m. on summer weeknights, when the electricity system is stretched thin cooling homes. Then the trucks automatically recharge overnight, when demand is lower and supply is more available.”

While many large vehicles like public buses are in use at peak times, some are well-suited to V2G. In the US, a scheme using electric school buses to support the grid (and get paid for it) has shown promise. 

Farmers often require a lot of machinery and, again, they are largely designed for one main purpose. But, as Forest Lodge Orchard has shown, if those machines are electric they will be cheaper to run - and if they can be plugged in at peak times and dump the energy stored in their big batteries automatically when the price gets high enough, it will make those machines more valuable. 

It is clear that any energy strategy being developed needs to think of cars and other vehicles not just as consumers of energy as they have been in the past, but as providers of energy storage in the future.

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Think of hydrogen as another type of battery, rather than an energy source. The issue is that it's not a very good battery. 

You start with electricity, you make hydrogen, you then use that hydrogen to make electricity again. Around one third of the energy you put in comes back out. This is not efficient and it also means hydrogen will be considerably more expensive than electricity for the customer. It’s better to just use the electricity in an electric machine or store it in a battery, if you can. 

There is potentially a role for hydrogen in heavy transport, steel and cement making etc where the advantages outweigh the inefficiencies, but even large mining operations are investing heavily in electric machines and many hydrogen trials have proven to be expensive and problematic.

Just as gas doesn’t need to play a role in our homes, hydrogen should not play a role in light vehicle transport. We don’t have a network of hydrogen stations, whereas we already have an electricity grid that spans most of the country and a growing number of solar installations where you can fill up your EV at home.

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Creating biogas from municipal waste or other waste streams is an interesting idea and a good example of a more circular economy, but so-called renewable gas is even more expensive than fossil gas and there's just not enough of it to make a dent. 

Some industries may need gas for a while as they transition to electric technologies, and we do use gas for electricity generation, but it is not a clean source of fuel, and it is certainly not renewable. A recently peer reviewed study has shown that it is even worse than coal for the climate due to its methane components, which is 80 times more potent than CO2 for warming. Gas definitely shouldn't be used in people's homes - it’s more expensive, it is running out, and burning it is bad for your health. Electric equivalents are more efficient, lower cost and much better for the environment. 

Around the world gas networks are shutting down because it’s clear the economics don’t stack up when compared to electricity. New houses should not be built with gas connections, because it locks families into decades of expensive, unhealthy gases in their home.

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Like highways, electricity lines are not always busy and have short periods of high demand. We will definitely need some grid upgrades to cope with the expected increase in demand as we electrify but, on average, our lines are at 30-40% capacity. So with smart demand management (like charging EVs or heating water during the day) and better pricing signals that encourage lower energy use and export at peak, we could increase that utilisation substantially without over-investing in new poles and wires, which will be paid for by customers over time on their bills. 

The more electricity generated by customers, the more hydro we can store for those winter peaks without the need to burn fossil fuels and the less need there will be for expensive, taxpayer funded upgrades of our network. Rooftop solar plays an important role here; when we have a dry year with not much rain, there are 5-10% more sunshine hours. 

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Batteries are are a crucial piece of the puzzle. While batteries are individually small, they add up. As an example, just 120,000 homes (or five percent of New Zealand households) 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. 

Every home with a battery basically removes themselves from peak, and it could potentially remove their neighbours from peak, too. 

Electricity use is also increasing in summer (largely due to air conditioning requirements and EVs) and this will have repercussions on lake levels in winter. Irrigation is also a major user of electricity in summer in some regions. Solar is well-suited to both of these cases as the electricity is usually required during the day when the sun is out, so more solar at home and on our farms can provide a lot of what we need with less strain on the grid and at the lowest cost.

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Demand flexibility is a crucial component of our energy system and all customers - whether large or small users - should be rewarded for reducing demand when required, or exporting at peak times. The recent Government Policy Statement on Electricity seems to back that view.

It’s total energy consumption, not electricity consumption, that is key to a sustainable future. We need to use less energy to do the same things, i.e. better efficiency. Electrification is the energy efficiency we’ve always been looking for - at both a small and large scale. 

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In our homes, switching to electric vehicles, hot water heating, space heating and cooking can reduce total household energy use by around 70% because heat pumps, induction stoves and EVs are on average 3-4 times more efficient at using energy than conventional fossil fuel machines. These homes will use more electricity but much less energy overall and this enhanced efficiency is where a lot of the savings come from.

Any reduction in electricity use above and beyond the main efficiency gain from electrification, whether through more efficient electric machines (e.g. LED light bulbs) or behaviour change (e.g. riding an e-bike instead of the EV) is a bonus, but electrification should come first to lock in the big-ticket emissions reduction and efficiency benefits.

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Even if electric homes get all their electricity from the grid rather than rooftop solar, they will still save a considerable sum compared to a fossil fuelled home. And generating your own electricity through rooftop solar brings those costs down further because it is consumed where it is produced. 

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The Commerce Commission decides how much the regulated monopolies can spend on upgrades and while bills are expected to rise to pay for those, Rewiring Aotearoa claimed a $1.2 billion win for consumers by arguing for more focus on the role customers could play. 

As an example, Mike Casey’s Forest Lodge orchard uses around 900% more electricity than the status quo because he has completely electrified all his farm machinery and now provides around 80% of that through solar generation and battery storage. The farm doesn’t use any additional electricity at peak times and that means there were no new poles or wires needed. 

A lot of the electricity we need for our increasingly electric lives could come from households, straight from the roof with no poles and wires in between. If that happens, it will actually reduce the need for expensive, taxpayer funded upgrades of our network. 

Like highways, electricity lines are not always busy and have short periods of high demand. On average, our lines are at 30-40% capacity, so with smart demand management (like charging EVs or heating water off-peak) and better pricing signals that encourage savings and export at peak, we could increase that utilisation substantially without over-investing in new poles and wires. 

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