Photo Noya Fields
NZ power company Vector says the uptakeof electric vehicles in New Zealand is sky rocketing: it is reporting a 190 percent increase in electric vehicle (EV) charging sessions in the 12 months to June, but this might not be entirely good news, and this growth adds urgency to some pressing issues raised in two reports last year.
Vector says it counted 66,000 charging sessions across its 18-strong rapid EV charging network in the 12 months to 30 June 2018, compared to 22,700 sessions the previous year, consuming a total of 590 megawatt hours of electricity.
Vector says that, collectively these 66,000 charging sessions saved 639,000 kilograms of CO2 emissions from entering the atmosphere. However it does not make clear whether this is the CO2 that would have been produced by the same use of fossil fuel powered vehicles, or whether that figure is net of CO2 released generating those 590 megawatt hours.
Vector CEO Simon Mackenzie said “There is no denying EVs are going to play a crucial role in achieving a clean green future for New Zealand,” adding: “While this is great news for the environment, there is still a lot of work to do as an industry to ensure New Zealand’s electricity infrastructure can handle the surge in demand for clean electricity to power our transport industry.
He said Vector was “working to understanding exactly how the rise of EVs will impact the way electricity is distributed across our networks, so supply can always meet demand.”
A tale of two charging reports
His comments come in the wake of two reports last year one impact of electric vehicle charging last year, one from Vector EV Network Integrationand one from New Zealand company Concept Consulting Group“Driving change” – Issues and options to maximise the opportunities from large-scale electric vehicle uptake in New Zealandcommissioned by three other power companies — Orion, Unison, and Powerco, that came to rather different conclusions.
The Vector report pointed out that electricity grids in residential areas have traditionally been sized according to the number of houses on a street, with little spare capacity, and were not designed to cater any significant uptake of EVs and the consequential demand for charging at home.
It said the problem would be exacerbated by the likely habit of many electric car owners coming home in the evening and putting their car on charge at the same time as normal domestic usage peaks.
Another major problem Vector envisaged is the move to rapid charging for cars with increasing battery capacity, some of which can take two days to trickle charge.
One car equals 20 households
According to Vector, a single EV household has the potential to increase its electricity capacity needs between 100 percent for very slow trickle charging, and 2000 percent for rapid charging. This, it says “is essentially adding between one and 20 additional ‘homes’ in terms of network capacity.
Vector said that, if only 10 percent of households adopted electric vehicles with rapid charging capability the network would be unable to cope.
It said time-of-use tariffs might provide short-term cushioning for network impacts at today’s low levels of uptake, but longer range/larger battery size EVs, combined with the reducing costs of EV fast chargers, would undermine pricing alone as a credible means to avoid peak capacity levels being breached.
“Pricing alone fails to recognise the value of dynamic scheduling, which through greater coordination of individual chargers, fully utilises network capacity throughout the day,” Vector said.
It advocated ‘smarter charging,’ which “has an added customer benefit of enabling EV users to become market participants whereby, for example, the aggregated, dynamic EV battery load can supplement the generation mix and add to community resilience.”
Also, Vector envisages that the growth of ride sharing schemes and the arrival of autonomous vehicles could see a reduction in car ownership, increase the use of dedicated charging facilities, and spread the charging load more evenly over the day.
Incentivised charging distribution
The Concept Consulting report argues that, if consumers can be incentivised to charge their vehicles in a way that distributes the load on the system, increases in peak power demand can be avoided.
It claimed that the current approach for charging for electricity — predominantly ‘flat’ $/kWh prices which do not vary across the day — will frustrate achievement of the benefits of electric vehicles and result in unnecessary costs being incurred.
“EV-owners will pay significantly more than they should for charging their vehicles. This will slow the rate of uptake of EVs, significantly increasing New Zealand’s emissions and increasing overall economic costs,” it said.
Overall, its report estimates that a permanent continuation of current pricing approaches will result in unnecessary increased costs of approximately $NZ4b (in present value terms, or $NZ14b in future cost terms), and CO2 emissions from internal combustion engine vehicles (ICEs) being over one-third greater in 2050.
Concept Consulting argued that these financial and environmental costs are avoidable with smarter, more cost-reflective electricity prices, which encourage EV-owners to charge their vehicles smoothly overnight in off-peak periods.
“Such smarter pricing, working in tandem with the technology embedded in EVs and their chargers, will: make EV charging much cheaper – thereby facilitating EV uptake; and avoid causing a material increase in peak power demand and associated costs and emissions.”
The report argued that time is of the essence for putting in place arrangements to facilitate the most positive EV outcomes before mass uptake starts to happen, and says all three power companies sponsoring the report “believe that pricing and managed charging – be it by a retailer, aggregator, network company or other third party — is central to this debate.”
