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EVs: What Do They Mean for Our Electricity System?

by Alan Eyes

For those planning on buying an EV the big news for the month is the Government ‘feebate’ announcement. There will be a rebate of up to $8625 for a new imported electric vehicle and up to $3540 for used imports. Trade Me reported over a 400% lift in EV enquires in the first week, but before you click “buy now” or dash to your nearest dealer, make sure you read the fine print.1

For most of us buying a car is a big decision with many things to consider – what do we need it for? How much will it cost to operate? Will it fit in the garage? And much more.

EVs are new to most of us and raise many more questions including – how and where to charge it? How far will it travel on a charge? How much will it cost to charge? While these are important questions, there are even bigger questions as to what it means to NZ – and will it really mean emissions free travel.

On 9 June the final version of the Climate Change Commissions report2 was released. Road transport emissions were 42.6% of New Zealand’s carbon dioxide emissions in 20183 and electrification of the vehicle fleet is seen as an important component in the initiatives to decarbonise NZ.

According to the NZ Herald Driven magazine, NZ currently has around 27,000 EVs, which is less than 1% of the 4 million total vehicles on our roads. Many of us know people with an EV, and charging the batteries is a new topic for conversation. Other than being told we are using electricity generated from renewable sources, ‘green’ energy, there has been little need to understand how the electricity is supplied and charged, and where electrical energy is coming from – this is about to change.

How and where to charge an EV needs to be carefully thought through before making a purchase, including how far you can drive on a charge, where and how you can plug-in, options for charging and how long charging takes, as well as how much it costs.

There are a number of practical, technical and safety aspects to charging an EV. These are particularly important for home charging and expert advice should be sought. To assist with this EECA and the Standards Association have produced a guide.4

An important consideration is the electrical wiring to and in our houses and whether it is capable of delivering the amount of power to charge the EV battery, while also still being able to use electricity for other things at the same time. Charging through a standard 3-pin wall outlet is possible for at least some vehicles. This is a slow option, probably over-night, but may be perfectly adequate for individual needs. The faster wall type chargers will need greater wiring capacity, and expert advice to avoid overloading.

Next, let’s consider the power network that supply our houses and businesses, and the capacity required in the lines, cables and transformers to deliver the electricity - locally this is Counties Power. As there is increased volume in EV charging from local networks, more planning is needed to ensure the right amount of electricity can be delivered. This is where things get more technical. Electricity systems need to be designed for the demand at peak times. As more people get an EV and all want to charge them at the same time, this could significantly increase capacity requirements. Investment is then required to upgrade the lines network, resulting in increased power bills. It is important technology, including smart chargers and phone apps, are used to spread the demand and avoiding inefficient network upgrades.

Wellington Electricity is currently consulting on an EV Connect Consultation Draft Roadmap which canvases these and other issues.5

And this is just the local aspects, investment would be required for upgrades on the national transmission grid also if the additional loads are not managed appropriately.

The prime objective of the Government ‘feebate’ scheme is to encourage the replacement of ICE powered vehicles with EVs in order to lower carbon emissions. But a move to zero emissions is only achieved if the electricity being used to charge an EV has been generated from renewable (green) electricity.

Until recently NZ had reached the proud status of 83% of electricity from renewable sources ie hydro, geothermal, wind and solar. But with NZ hydro lakes, like the Auckland water reservoirs, being well below average and issues impacting the availability of natural gas, large amounts of coal are needed to generate electricity at the Huntly power station. This, and other measures, is enabling the lights to stay on without the need for a public conservation, but it means more CO2 emissions, reducing the renewable electricity percentage to 73% in early June.

How the NZ electricity market works is complex, but there is reason to say each additional EV being charged from the grid is in effect currently requiring thermal fuel (natural gas or coal). When our hydro lakes are full and/or more renewable energy generation plants replace thermal plants the equation will change.

The announced ‘feebate’ for EVs has certainly sparked controversy. Not least of all because funding for the rebate will be coming from a levy on new petrol and diesel powered vehicles.

Not all consider plug-in electric charging to be the ultimate to replace our current internal combustion engine (ICE) vehicles. Large industry players such as Toyota and Hyundai continue development of fuel cells and hydrogen powered units, and we already have a few larger such vehicles operating in NZ. These technologies may in fact be better suited to the NZ geography, demographics, and lifestyles.

As we increase the number of EVs on our roads it is important the impact on our electricity infrastructure is carefully managed. Likewise, to achieve zero emissions we need to be informed on the generation source being used for charging these additional vehicles and that it is from renewable energy.

  1. https://www.nzta.govt.nz/vehicles/clean-car-programme/clean-car-discount/ 

  2. https://ccc-production-media.s3.ap-southeast-2.amazonaws.com/public/Inaia-tonu-nei-a-low-emissions-future-for-Aotearoa/Inaia-tonu-nei-a-low-emissions-future-for-Aotearoa.pdf 

  3. https://www.stats.govt.nz/indicators/new-zealands-greenhouse-gas-emissions 

  4. https://www.standards.govt.nz/get-standards/sponsored-standards/electric-vehicle-ev-chargers-for-residential-use/ 

  5. Consultation closes 15 July 2021. See https://www.welectricity.co.nz/about-us/major-projects/ev-connect/document/260