Wed Feb 4, 2015 6:30pm GMT

A judge in New York has ruled Entergy Corp cannot stop hearings on the state's plan to shut the company's Indian Point nuclear power plant for part of the summer to protect fish in the Hudson River.

In a ruling late Tuesday, an administrative law judge at the state Department of Environmental Conservation (DEC) rejected Entergy's latest attempt to stop the state from shutting the plant, at least for part of the summer.

The ruling was the latest salvo in an eight-year battle between Entergy, which wants to run Indian Point for another 20 years, and the state, which wants the plant shut.

The 2,061-megawatt plant, located about 40 miles north of Manhattan, provides about a quarter of the power used in the New York City area.

The state's power grid operator and local utilities have said the shutdown of the plant could threaten the reliability of the power grid and boost prices in the Big Apple.

The judge, Maria Villa, made the ruling on Entergy's attempt to quash the DEC's 2013 proposal that Indian Point shut for at least 42 days each year, between May 10 and Aug. 10, during prime fish migrations.

That is also the time of year Indian Point produces much of its revenue because power prices are generally highest when air conditioning demand peaks during the summer.

"The rulings provide for evidentiary hearings on DEC staff's proposal ... Entergy will participate fully in such hearings even as we preserve our position that they are unnecessary," the company said.

The hearings are expected to continue through 2015.

Indian Point withdraws up to 2.5 billion gallons of water a day from the Hudson to cool equipment, and then discharges it back into the river a little warmer than before.

Environmental groups and the DEC have long argued Indian Point's water intake system kills about a billion fish, fish eggs and larvae each year, and that the plant should install cooling towers to reduce the use of river water by recycling it.

Entergy said cooling towers are too expensive, with an estimated cost of up to $2 billion and could not enter service before 2029. Instead, it has proposed installing a Wedgewire screen system to protect fish.

The company said the screens would save more fish as it would take only about three years to install at a cost of up to $250 million.