The Environment Court's rejection of plans for a wind farm between Napier and Taupo means clean renewable energy worth $800 million will be wasted, says lines company Unison.
It was the second time the court had turned down the application for the project on Te Waka Range.
Unison removed three turbines from its original design and resubmitted its application last year.
The Hastings-based company's chief executive, Ken Sutherland, says the company went to considerable lengths to change the project in order to satisfy any objections by Maori.
Mr Sutherland says the second refusal sends seriously disconcerting signals to companies that want to produce environmentally friendly electricity.
The Wind Energy Association has also expressed disappointment at the decision.
Association chief executive Fraser Clark says the wind farm would have made a valuable contribution to New Zealand's energy supplies.
Mr Clark says the association, whose members include electricity generators and wind farm developers, will study the judgment closely.
He says it may prompt discussions with the Government over reforms to the Resource Management Act.
But Hawke's Bay historian Patrick Parsons says the decision is a victory for common sense and tenacity.
Mr Parsons, who gave evidence at both Environment Court hearings, says Te Waka range is an outstanding landscape that needs to be preserved.