A New Zealand wide power "emergency" has led to outages in Waikato tonight.
Transpower New Zealand GM of operations Stephen Jay says demand for electricity is at an all-time high.
"Insufficient generation has been made available to meet demand and manage a secure system," Jay said.
"As a result, Transpower has asked the distribution companies to reduce load.
"Different companies will do this in different ways, some manage via load control on hot water, some manage via customer disconnections."
In a Grid Emergency Notice, Transpower says it's a New Zealand wide emergency, although for now it appears only properties in the Waikato have been affected.
At 8:30pm, thousands of properties were affected by the outage on the WEL Networks website. Just before 9pm, WEL Networks released a statement saying power is now back on.
"Due to insufficient generation to meet New Zealand’s electricity load demands, all electricity distribution business were instructed by Transpower earlier this evening (the national grid operator) to reduce the amount of load on our network with immediate effect," WEL Networks said.
"This was a New Zealand-wide emergency. We have just been authorised to restore power to affected areas.
"We do apologise for any inconvenience caused, and we thank you in advance for your patience and understanding."