Police and Genesis Energy will decide in the next few weeks whether to charge nine Greenpeace protesters who scaled a 150m chimney stack at Huntly Power Station today.
The protesters came down from the stack at the north Waikato station, run by Genesis Energy, about 11am today after they had scaled it about 6.30am.
Police served them with trespass notices when they reached the foot of the stack but they have not been arrested or charged.
"Police say they will consider laying charges against the protesters after talks with Genesis Energy," Waikato police said.
Greenpeace said the protesters were demonstrating against coal-fired power and said Huntly Power Station was the biggest climate polluter in the country.
Genesis spokesman Richard Gordon said the protesters decided to climb down after negotiations about 10.15am.
"We understand they may have drilled some holes in the stack and lifted some gates of hinges," Mr Gordon said.
"We will have a look in the next couple of days to assess how much damage they have caused and look at whether we want to lay charges after that."
He said the protesters had been unable to unfurl a banner fully on the stack due to high winds.
Monitoring gear on a security fence had been damaged when the protesters cut through the fence, he said.
"It is causing a few safety concerns," Mr Gordon said.
"On top of the stacks there is quite a lot of data communications gear we and Transpower use and there is some concern about possible inadvertent damage to that gear on top of the chimney."
The protest persuaded Climate Change Minister David Parker to cancel a planned meeting with Greenpeace this afternoon in Auckland.
Mr Parker was due to receive a report from Greenpeace on their ideas for reducing greenhouse gas emissions.
"This stunt is a real disappointment," Mr Parker said.
"Not only is it unnecessary but it potentially puts lives at risk. I am surprised Greenpeace has not shown better judgment.
"While I can understand Greenpeace's concern to get its message about climate change across, this illegal stunt is a step too far.
"I have met with Greenpeace previously and will meet with them in the future, but I am not meeting with them at the moment."
Mr Gordon said Genesis was building a $520 million natural gas turbine next to the Huntly coal burner and the company was aiming to cut coal burning in the future.
"You can't disagree with the fact that Huntly is New Zealand's only coal-fired power station, it is New Zealand's biggest power station and it emits CO2, which is one of the greenhouse gases," he said.
"We are building a new gas turbine which is going to reduce CO2 emissions by a huge amount, and replacement of the coal station is a long-term goal, but we can't replace it immediately.
"There are 1.3 million people who get their power from this station in the upper North Island and if we cut this station off now there would be a lot of people who were cold and in the dark this winter."