Transpower is assuring people there's no risk to the power supply despite one company suggesting there was

Electric Kiwi sent out alerts asking customers if they could reduce their power as the national grid was potentially tight.

But in the body of the email it said it was a part of a trial to help prioritise future ways for customers to lower their demand.

Transpower says it's a cold night with high demand, but if there was a risk to the electricity supply it would be passed on to the public.

It says the message is Electric Kiwi operating off its own back.

Electric Kiwi has been approached for comment.