Christchurch City Council says it has been refunded $250,000 after being overcharged for its streetlighting by Contact Energy.
It comes after the Electricity Authority lodged a formal complaint with an independent rulings panel against the power company.
The authority alleges that between early March 2022 and the end of September 2025, Contact failed to maintain an up-to-date distributed unmetered load (DUML) database for the council.
It also failed to take all practicable steps to ensure submission information was complete and accurate.
Contact has accepted it breached the code, and potentially faces a penalty of up to $200,000.
The authority said Contact was responsible for the council's streetlight database in the period.
It further noted Contact failed to address DUML accuracy issues identified across several audits, resulting in the overcharge.
"The investigator assessed the market impact as high, with an over-submission of 4.94 gigawatt hours of electricity between March 2022 to September 2025," the authority said.
Christchurch City Council head of facilities and property Bruce Rendall said the discrepancy was identified by an independent auditor, after which Contact confirmed the overcharge.
"The matter is limited to streetlighting charges," Rendall said. "Council is not a party to the Electricity Authority's current complaint process."
The council manages a streetlighting network of approximately 44,000 lights.
The largely LED network was operated through a central management system with smart controllers on individual lights.
Contact accepts it breached energy code
Contact Energy said it was taking steps to ensure the over charging of Christchurch City Council does not happen again.
It said it had implemented processes to ensure that street light dimming was accurately captured and it accepted it breached the Code.
Christchurch City Council has been reimbursed $250,000.
Contact said the issue related to a historical matter where Christchurch City Council implemented streetlight dimming.
It said Contact have been collaborating with Christchurch City Council for a lengthy period of time to implement a solution to reflect the impact of street light dimming to the market and Christchurch City Council energy bills.
