Noise controls for a Manawatū wind farm will continue to be discussed with the microphones off after late-night discussions produced a possible solution.
The Te Rere Hau wind farm operator NZ Windfarms arrived at the final day of a hearing on Thursday with new proposals for managing annoying noise that might satisfy the neighbours.
Chief executive John Worth said they had been developed after “many hours” of discussion the night before with acoustic experts and affected neighbour Lee Huffman.
The alternative plan would focus on the operation of a couple of turbines closest to the neighbours, rather than impose a blanket rule across the whole Tararua Range site.
But lawyer for Palmerston North City Council John Maassen said more time was needed to refine the options.
He said the council was prepared to consider that there could be a better solution than what it had proposed.
“But we would need to think about how to frame that very carefully.
“Some of this is not pitch perfect because it has developed overnight,” he said.
The council’s proposal was to impose a blanket restriction on the whole wind farm that would stop generation at wind speeds of less than 8 metres per second.
The council’s acoustics consultant Tom Evans said that threshold was designed to keep noise to a “reasonable” level. It would not mean the turbines could not be heard at all.
He said he was open to considering an alternative, but it would have to be backed up by evidence that it would be effective.
A history of more than 1700 complaints showed the noise from Te Rere Hau was most annoying when it was almost calm and quiet at residents’ homes, but a southeasterly breeze was still enough for the turbines to generate electricity and noise.
Those were the times residents were most likely to want to be outside enjoying the peace and ambience of their rural residential setting.
Worth proposed the key turbines would be stopped and would not start again until one minute after wind speeds rose above 9m per second during summer.
The restrictions would apply from December until the end of March, from 6am until 10pm on weekends and public holidays, and on weekdays from 6pm until 10pm.
As a tradeoff, the rest of the farm would be able to operate at wind speeds of a lower 6m per second.
Worth said his proposal should be imposed instead of the council’s blanket wind-speed rule.
“We do not think it would be appropriate to have a mixture.
“We do not think it’s equitable to have both.”
At the end of each summer, the company would produce a compliance report.
It would also set up a community liaison group that would meet regularly to share information between the company and residents.
In addition, NZ Windfarms would, by December 2017, make changes to gearboxes to reduce noise.
Lawyer for NZ Windfarms Vicki Morrison-Shaw said the company was committed to becoming a better neighbour, but the council’s proposed conditions went further than was “necessary and reasonable”.
“It imposes a significant constraint on NZ Windfarms which is out of all proportion to the effect seeking to be mitigated.”
The parties have been asked to provide the hearing panel chaired by commissioner Paul Rogers with a memo outlining the timeline for refining a proposed set of conditions.
The commissioners will then consider the information in private before releasing a decision.