Context and problem definition
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Electric vehicle uptake is on the rise and charging is predominantly done at home
The uptake of electric vehicles (EVs) is expected to gradually increase as the economics improve and people and businesses replace their vehicles. At the end of May 2025, there were nearly 121,000 light EVs in New Zealand, including plug-in hybrids, which is up 12.5 per cent from May 2024.[1]
There are many different charging options available for EVs:
Type of charger:
- The portable 3-pin charger supplied with the EV that plugs into a standard power point — provides a slow (usually overnight, depending on battery size) charge.
- A standard fixed charging unit — provides faster, more convenient, and safer charging (compared to a portable 3-pin charger), and often programmable by the user. Requires install by an electrician.
- A ‘smart’ fixed charging unit — as above but capable of two-way communication with connectivity and interoperability that allow the charger to easily interact with the electricity system and charge dynamically. Requires install by an electrician.
Output of charger:
- Direct current (DC) fast chargers — the fastest charging option, built in charging cable/plug.
- Alternating current (AC) chargers — offer a slower charge than DC, either built in charging cable/plug, or customer supplied.
Application:
- Public – uses fixed charging units (both smart and standard), and can be AC or DC depending on charging speed required
- DC - Typically used for public charging e.g., on state highways.
- AC – Typically used at places like supermarkets and malls.
- Private – can be portable or fixed charging units (both smart and standard), typically AC, but DC can be used for specific business needs.
Common EV charger sizes are 7.4kW AC (for home use), 22kW AC (for business/public use), 50kW DC for business/public use, and up to 350kW DC for much larger very fast public charging.
What do we mean by a ‘smart charger’?
The term ‘smart’ is used widely when talking about EV chargers, but it can be used to refer to very different levels of functionality. For instance, an EV charger that can simply connect to the internet or be controlled through an app is often described as ‘smart’ in its marketing material.
Smart in the context of this paper means chargers that have two-way communication with connectivity and interoperability that allow the charger to easily interact with the electricity system and charge dynamically.
Breaking it down further, a smart charger:
- uses standardised communication protocols, that enable a range of systems to easily connect and control them
- has a minimum set of responses available e.g., turn on, turn off, turn up, turn down
- measures and can provide a minimum set of data externally e.g., charging duration, amount of electricity used, or current power demand.
Chargers meeting a minimum level of smartness will ensure that they can be used to:
- manage demand (peak load) either generation constraints or distribution constraints
- optimise the use of renewable energy
- enable the development of a flexibility market
- enable greater consumer control over how and when their charger is used, including to reduce their electricity costs.
This paper discusses options to increase the uptake of smart chargers
Fixed charging units (as described above), now referred to as “chargers” in this document, come with an upfront purchase and installation cost to the consumer.
Currently, most EV charging takes place at home and is done using a portable 3-pin unit.[2] Energy Efficiency and Conservation Authority (EECA) research on current EV owners shows only 19 percent of charging at home is done using a smart EV charger.
Some EV chargers also provide for two-way (bidirectional) charging, enabling the EV battery to power a household or be a source of electricity supplied to the grid, providing demand flexibility and potentially a more resilient supply of energy. This is referred to as Vehicle to Home (V2H) and Vehicle to Grid (V2G) respectively. The term V2X is used to refer to power feeding from a vehicle to an end use e.g., home, the grid, or a product.
These activities could become more prevalent in future as technology develops so there may be a need for some standard functionality to ensure V2X can integrate into and support the electricity system.
EV chargers can also be integrated into other products such as solar or battery systems. It is beneficial if smart functionality applies across all these systems when this integration occurs.
Widespread electrification is causing the need for electricity infrastructure upgrades, costing all consumers
There is a risk that household peak electricity demand could significantly increase (estimated at up to 40 per cent by 2050[3]) as EV uptake increases. Alongside wider electrification of households and industrial processes, this potential for higher electricity demand peaks causes a need for electricity network upgrades.
The costs of infrastructure upgrades are passed onto all consumers. The Commerce Commission’s 2025 default price-quality pathway (DDP4) decision (regulating electricity distribution network revenue) noted that bills would rise by about $10 per month from April 2025, partly due to higher levels of investment.[4]
Managing increased electricity demand through smart charging could reduce infrastructure requirements and costs for all consumers
Demand flexibility is the ability for consumers to use smart devices, such as EV chargers, to easily optimise their energy use for their benefit and wider system benefits. The benefits come from reduced costs, reduced electricity consumption (or injection) when there is a tight supply of generation or network constraints, and consuming electricity when intermittent renewables are available e.g., wind and solar.
Smart charging provides EV owners with demand flexibility and the opportunity to take full advantage of electricity bill savings that can more than offset the upfront cost of installing a charger. A smart EV charger is one which is capable of two-way communication (can send and receive information) and can respond to signals (e.g., to turn on, off, up or down) to dynamically manage when and how charging occurs.
Transpower estimates that smart EV charging can reduce peak demand by 1.9 GW (18 percent) by 2035[5], reducing or deferring the need for electricity infrastructure upgrades. EECA modelling shows widespread use of smart and energy efficient EV chargers could save the country $4 billion by 2050.[6]
The best chance of realising the potential of smart chargers is now while we can influence the types of chargers being supplied
EV chargers can last up to 15 years (depending on a number of factors including type, size, and usage), so each EV charger installed now that is not smart will lock in non-dynamic EV charging for some time. EV chargers have the potential to be the cornerstone of a smart home and a building block for wider adoption of distributed flexibility across the energy system.
Charging smartly means we can make the most of New Zealand’s highly renewable energy to:
- enable better use of local intermittent renewable generation such as solar and wind, supporting energy security and resilience
- deliver our domestic and international climate goals, including COP28 with commitments to double energy efficiency and triple renewable generation by 2030.
As more new intermittent renewable generation is built, demand flexibility will be more valuable to both individual users and the system as a whole. Electricity network owners, retailers, and third-party service providers, need to be able to rely on common functionality in chargers to enable them to be managed dynamically. Consumers also need certainty their charger will be interoperable with different systems including networks and retailers. If non-smart chargers are installed at scale, New Zealand may lose the opportunity to reduce electricity infrastructure costs. There may also be an underdevelopment of the flexibility market if end devices do not have common functionality and control.
Questions for consultation
1. Research indicates that most EV charging occurs at home. Do you have any comments on the split between private (home) and public charging and how this may change into the future?
2. Do you have comments on the current state of private EV charging in New Zealand?
3. Do you agree that smart charging can support network infrastructure needs, and in turn realise benefits for end consumers?
4. What are your views on whether the supply of chargers in New Zealand would move to predominantly smart charging without regulation?
5. Do you have any comments on the availability of private EV charging for varying demographics, for example, homeowners versus renters?
Please provide evidence or data where possible to inform our analysis
Footnotes
[1] Fleet statistics(external link) — Ministry of Transport
[2] Using the portable charger that comes with the EV that plugs into a normal power point.
[3] Shifting gear, How New Zealand can accelerate the uptake of low emission vehicles [PDF 1.5 MB](external link) — Concept Consulting and Retyna (October 2021)
[4] 2025 reset of the electricity default price-quality path(external link) — Commerce Commission New Zealand
[5] TP Whakamana i Te Mauri Hiko.pdf(external link) — Transpower
[6] Residential smart EV chargers and demand flexibility(external link) — Energy Efficiency & Conservation Authority