It also questioned the structure of the Resource Management Act, which allowed government funding for opponents, while the Government was supporting the proposed wind farm.
TrustPower community relations manager Graeme Purches said yesterday, when contacted after the hearing close, costs would have to be borne by Clutha District Council and Otago Regional Council ratepayers, and TrustPower.
District council ratepayers were likely to bear a 0.5% increase in rates because of hearing costs.
"We fully support the process and decision being made by the councils but we end up with Contact Energy and a lobby group hijacking the process," he said.
"It gets taken out of the hands of locals and that is a shame."
But his claims were disputed by the Upland Landscape Protection Society, which said opponents were picked off with financial threats and the society represented many Mahinerangi residents.
Mr Purches said TrustPower's costs for the 15-day court hearing had not been finalised but it was costing the power company tens of thousands of dollars every day.
The society did not represent many Mahinerangi residents, he said.
The company supported the process but the way it was set up had faults.
The landscape protection society received $30,000 from the environment legal assistance fund, which was sourced from the Crown, administered by the Ministry for the Environment.
The fund provides non-profit groups with financial assistance on an environmental issue of public interest.
Mr Purches said the society was bankrolled by a fund administered by the ministry, yet the Crown, through the ministry, supported the wind farm and had made submissions to support the proposal.
The Contact Energy appeal was strictly about competition, he said.
There was a perception in New Zealand there were plenty of sites for wind farms around the country, which was not true, Mr Purches said.
"This site staked up", having the wind and land resource, and being right beside a hydro scheme.
The district council, the lead authority in the hearing, was looking at a bill of about $50,000 for the hearing, which may bring a 0.5% increase in rates.
Council planning and environment manager Murray Brass said the council would look to recover costs if the appeals were declined. The way the process was set up the council had to bear costs.
He said as the society was an incorporated body and had no money, there was little chance of recovering costs from it.
The regional council had yet to tally all costs but it would be more than $20,000. It would be looking to recover costs.
Society co-ordinator Ewan Carr said Mr Purches was talking nonsense.
Mr Carr said the society represented Mahinerangi farmers affected by the wind farm. The process had become litigation through financial attrition.
Threats of opponents having to pay costs led to them withdrawing.
Contact had argued the appeal was not about competition but was about creating an adverse environmental effect, through the spillage of water at its Clutha River dams.
It also wanted transmission lines upgraded.
