Neighbours of the Te Rere Hau wind farm say the sound generated from turbines whizzing around is sometimes annoying.
Two residents with very different views have described what it's like to live near a noisy wind farm in Manawatū – one isn't bothered by it, and the other wonders if "this saga is ever going to end".
Dr Lee Huffman has maintained a detailed log for 10 years, recording "whining", "mechanical grinding", a "whoosh" and a "roar" from the Te Rere Hau wind farm on the Tararua Range.
Joseph Poff, on the other hand, has slated the Palmerston North City Council for "harassing" NZ Windfarms about noise. "I'd like to see a lot better use of ratepayer money," he said.
The council has battled with NZ Windfarms in the courts and commissioners are now reviewing what rules there should be to control noise from the farm.
"We want to be able to be outside of our home when it's calm," Huffman told commissioners at a hearing in Palmerston North on Wednesday.
"We want to be able to open our windows and not hear the whine... or the roar.
"We want to be able to open our windows at night."
On a still day in the countryside, there could be "whining, roaring and grinding so intrusive that we don't want to be outside".
The first time Huffman heard the Te Rere Hau farm, it woke her up. She wondered what her husband Graham Devey was doing. "What was he doing in the barn that was causing such a racket?"
Huffman told commissioners the problems were worst when wind speeds were low, particularly between 6 metres per second and 10m per second. She backed the city council's position, that there should be an 8m per second threshold before the turbines kick in at night. She also said subjective assessment was a legitimate way to monitor noise.
Poff was having none of that. The 2010 New Zealand noise standard indicated NZ Windfarms should be able to run its turbines at 6m per second and commissioners shouldn't deviate from that, he said.
"It seems to me that the city council's position is that it's now attempting to change the New Zealand standard to fit the complaint.
"My personal experience has been no negative impact on my lifestyle or that of my children."
Poff pointed out NZ Windfarms had complied with its resource consent. Lawyers were the only winners out of the dispute, he said.
NZ Windfarms chief executive John Worth said there had recently been a "reasonably comprehensive reversal in style" on engaging with neighbours.
The company previously had a formal style where the focus was on complying with the letter of the law. The new approach was to understand the conditions causing problems for neighbours and do better than just comply with the company's legal obligations, he said.
NZ Windfarms engineer Dr Jamie Wallace said the company was refining a system designed to prevent turbines from operating during conditions thought to cause annoyance to neighbours. That involved using sophisticated software and adjustments could be made in real time to switch off some turbines.
Te Rere Hau site manager and electrical engineer Adam Radich said reducing wear on gearboxes helped reduce noise.
NZ Windfarms was also curtailing production so the turbines would operate when the revenue was worthwhile and would not run when it wasn't profitable, he said.
Low spot prices tended to coincide with hours of darkness, evenings, weekends and in summer, which was also when residents wanted to spend more time outdoors.
"NZ Windfarms can run the farm in a smarter way and reduce noise effects."