EV drivers enjoy incentive to charge off-peak
24 November 2017 – Electric vehicle (EV) drivers are responding well to price signals suggesting there will be
sufficient energy capacity, predominately renewable, to power New Zealand’s increasing uptake of EVs well into the
future, according to Mercury.
Mercury data shows that the 20% discount Mercury offers for overnight EV charging significantly moved charging use to
between 11pm and 7am.
Chief Marketing Officer Julia Jack said that a clear change in electricity consumption patterns could be seen with
customers taking advantage of the 20% off-peak price discount offered by Mercury.
“While individual household electricity use peaked around midnight as EV charging drawdown was highest, analysis
suggested that it would take eight in every 10 households in a neighbourhood to have an EV before overnight charging
would exceed the usual evening usage that networks currently manage,” Ms Jack said.
When looked at in the context of New Zealanders’ July winter usage, where New Zealand’s overall electricity use is
highest, it suggests significant capacity is available for EVs charging overnight.
“This is an important insight as the electricity sector considers the opportunities and risks of large scale uptake of
EVs in New Zealand.
“With around 85% of New Zealand’s electricity generated from renewable energy sources, transitioning vehicles to EVs is
New Zealand’s largest green growth opportunity,” Ms Jack said.
“Because of our renewable electricity base, each EV that replaces an internal combustion car in New Zealand represents
about two tonnes less carbon going into the atmosphere every year.”
While there are around 5,500 EVs currently registered in New Zealand, numbers are expected to double year-on-year. This
is supported by a 2016 government target of 64,000 EVs registered in New Zealand by the end of 2021 and a coalition
government commitment to making its own light vehicle fleet emission free.
Mercury compared the electricity consumption of customers on an EV charging price plan before they signed up to the
plan, and then after they signed up. It then compared those customers against a sample of general customers.
The data showed that there was no material increase in morning or evening peaks of household electricity use, some extra
usage during the day and in the evening shoulder period, and a distinct increase after 11pm and overnight when the
national grid has a large amount of spare capacity.
“This suggests that pricing is a simple and effective way to ensure there is nothing to stop New Zealand maximising the
wonderful opportunity of EVs for consumers and for the country overall,” Ms Jack said.
New in-car technology is also helping to ensure capacity is not an issue by spreading charging over the course of the
night rather than all vehicles charging near the start of the off-peak period.
“We recognise this data is from a small set of customers – 63 who have smart meter data for the period October 2016 and
July and October 2017, and who changed to an EV tariff between those dates,” Ms Jack said.
“Mercury will continue to monitor patterns of charging behaviour to ensure the right options are provided for customers.
“We look forward to working with network providers by testing and sharing insights so that New Zealanders, and New
Zealand, can take advantage of the EV opportunity. And, of course, we remain focused on finding more ways to accelerate
the uptake of EVs in New Zealand,” Ms Jack said.