HAYWARD — In what some residents and local officials are calling a major victory, state regulators on Wednesday pulled the plug on a Texas company's plans to build an energy plant near the Hayward shoreline.

"It's good news for Hayward," said resident Rob Simpson, who has opposed the Eastshore Energy Center since it was first proposed two years ago. "We set a precedent of public participation to a degree that (the state Energy Commission) hadn't seen before."

The Energy Commission voted against permitting Austin, Texas-based Tierra Energy to go forward with Eastshore, a 115-megawatt facility that would have used natural gas to power 14 enormous internal combustion engines to generate electricity during times of peak use.

But while Simpson and other environmentalists heralded Wednesday's decision as a win for clean energy, the commission's vote was based mainly on the grounds that the plant could have potentially interfered with planes using the nearby Hayward Executive Airport.

Studies and testimony that were part of the evidentiary hearing stated that thermal plumes of hot air from the plant — pitched for a tract near an airport runway approach — would pose a potential hazard for pilots at low altitude.

"Since the plumes are invisible, pilots could encounter unexpected turbulence and have an unexpected upset or crash," said Susan Gefter, the state panel's hearing officer. "It is an aviation hazard to the health and safety of the public."

Tierra attorney Jane Luckhardt called the existing studies on which the decision was based "conservative," and said their own examination indicated results would be far less drastic.

The case is the first time the panel has cited airport proximity to determine a siting issue, but the written decision makes clear it is a special case that will not be considered a precedent.

"The Hayward airport has the lowest traffic pattern altitude in the state to avoid patterns using Oakland and San Francisco airports," Gefter said, adding that the previously approved Russell City Energy Generator project in the area would just add to an already dangerous situation.

In addition to the air traffic problems, the decision states that the Eastshore proposal does not jibe with Hayward's general plan, which designates the area as a future business and technology corridor.

Luckhardt said those concerns were not outlined in any specific parameters, and similar vagaries could prove difficult to discount at future hearings.

"This committee relied on the testimony ... by local intervenors whose express purpose was to have the plant not certified," Luckhardt said.

The commission could have overridden concerns regarding the general plan if it saw fit, but ultimately those in attendance unanimously agreed with presiding commissioner Jeffrey Byron's decision that "benefits do not override the impacts on the public's health and safety." Commissioner James Boyd was absent.

Byron said that he wanted from the beginning to get the plant approved, but after testimony from officials and citizens, became convinced there were "unmitigable impacts that made it not possible to support."

He also said he was concerned about the applicant's conduct during the hearing because Tierra appeared to urge that the matter be expedited at the cost of necessary intensive study.

However, Byron stressed that there remains a clear need for more power plants in California.

"Despite public perception, this was a difficult decision for me to recommend," he said. "The state needs cleaner power plants, and the state narrowly trumps local interest."

Byron described the problem as "everyone wants to go to heaven but nobody wants to die."

"We all use electricity, but nobody wants a generator to be built near them," he said. "If only we could convert all those gas guzzlers to electric vehicles. But then where would we build the power plants?"

Eric Kurhi covers Hayward. Reach him at ekurhi@bayareanewsgroup.com or 510-293-2473.