Distributed Energy Helps Grids Balance EV Charging

When a growing population and a surge in electric vehicle uptake signalled potential strain on the grid of a small town in Aotearoa (New Zealand), the regional utility embarked on an experiment with a smart grid software product to hold off costly hardware updates—with promising results.

Wel Networks, the utility serving residents in the coastal town of Raglan, conducted a pilot study to determine how distributed energy resource management software (DERMS) can maintain reliability when projected EV use threatens to exceed grid capacity.

“EVs draw large amounts of power when charging, particularly at specific times of the day when many EVs are connected to the grid, such as during overnight charging,” writes Andy Miller, business development director at grid software company PXiSE, in an article for Power Grid International.

EV usage is surging across Aotearoa, he adds, comprising 20% of all new car registrations as of December, 2022, up from just 4% the previous January. For places like Raglan, a town of 4,000 with “a cultural affinity for an environmentally friendly lifestyle,” EV adoption is expected to be particularly high, with an outsized impact on electricity use.

When WEL Networks recalculated its future power demand to factor in increased EV charging, it found that Raglan’s power needs would outstrip supply from current infrastructure in 2023, decades earlier than its previous prediction of 2063. Were it to rely solely on hardware upgrades to meet this rising demand, WEL Networks would be forced to schedule an expensive new transformer for the Raglan substation, plus a 33-kilovolt sub-transmission circuit, much earlier than anticipated.

Those hardware upgrades will eventually be inevitable, but WEL Networks decided to explore options to delay the work while resolving capacity issues. It launched a pilot study with PXiSE Energy Solutions, whose DERMS was used successfully in Australia to manage energy flows in a community solar project.

DERMS can maximize the number of distributed energy resources (DERs) like solar panels and EV chargers on the grid, while also managing or time-shifting peak load. As PXiSE explains, can help utilities manage the increase in renewable energy assets, batteries, and EVs by using an integrated software platform to coordinate the flow of energy, both between utilities and customers.

“WEL Networks staged a pilot involving 11 of the utility’s customers and their distributed assets, which included solar panels, home battery storage units, controllable load via demand response enabling devices, and EV chargers,” writes Power Grid International. “Throughout the pilot, WEL Networks tested how the DERMS managed different high-level network scenarios including imbalances between load and demand as well as outages.”

And the outcome was positive: “The DERMS provided newfound visibility into how the EV chargers and other DERs interact with the grid while also providing alarm and reporting functions, making it possible for WEL Networks to take a proactive, rather than reactive approach to managing the device loads.”

With three case scenarios, including system outages and imbalances between load and demand, the first phase of the pilot study “cleared the path for further testing and increased scenario complexity,” PXiSE says.

For the second phase, the company plans to increase the size of the customer group to demonstrate broader DERMS capabilities. The third phase will deploy DERMS Raglan-wide.

“The pilot results have laid the foundation to allow WEL Networks to easily scale up as needed,” writes Power Grid International, with the possibility of eventually deploying DERMS throughout its regional network.