Generator floats an ecological alternative for power plant

NRG is pushing for a closed cooling system instead of using seawater at El Segundo station.

Kristin S. Agostoni
Daily Breeze
07/23/2007

The NRG power plant in El Segundo has filed plans with state energy regulators to build a closed-cycle system that would no longer use ocean water to cool its turbines.

An application submitted last month with the California Energy Commission provides a detailed look at the project that has already won praise from environmentalists.

The company hopes to receive approval to redesign the Vista del Mar generating station by the end of the year, said Steve Hoffmann, NRG's western region president.

The practice of pumping in saltwater, circulating it through turbines and releasing it back out to sea is also used at the AES plant in Redondo Beach and at the Los Angeles Department of Water and Power's Scattergood facility near Los Angeles International Airport and at the Terminal Island generating station. Environmentalists have long criticized the process for the amount of aquatic life it kills.

"This is the first time we've seen an energy company take action on their own without pressure," said Sarah Abramson, a staff scientist with the environmental group Heal the Bay.

"I really see it as signifying the downfall of once-through cooling," she added.

Ocean-water cooling systems have come under fire in California and elsewhere.

Earlier this year, the practice suffered a blow when the U.S. Court of Appeals for the 2nd Circuit ruled that the Environmental Protection Agency had no basis for letting electricity generating stations suck in ocean water if other measures were taken, such as replacing sea life with fish nurseries.

The suit had been filed by a number of groups, including Surfrider Foundation and Santa Monica Baykeeper, and the ruling has forced the EPA to suspend rules it made in 2004.

Despite heavy pressure from environmentalists, the El Segundo station had won approval in February 2005 to demolish and rebuild half its plant using once-through cooling.

However, the site has sat mostly idle while the company has sought financing for the overhaul.

Hoffmann said NRG decided to reverse course in large part because of technology that wasn't available two years ago. The rapid response system will allow the plant to come online much faster at peak periods; it could operate at 60 percent capacity in 10 minutes and at full capacity in one hour, he said.

NRG today runs about 15 percent of the time, through a short-term tolling agreement with Southern California Edison and at the direction of the state's Independent System Operator. Hoffmann said the company hopes to secure a long-term pact with the power company that would help it attract financial backers for the overhaul.

But Hoffmann also said the company was concerned about complying with federal Clean Water Act standards. "We weren't sure what kind of technology would really work to prevent these small ocean organisms from coming into our intake," he said.

In place of using seawater, NRG plans to use an air-cooled system that allows for water and steam to be recycled and re-circulated. The plant would sit on a slightly larger footprint and also include two water storage tanks, the application states.

A 10-foot seawall would also be moved toward the western property line to mask sounds for those on the beach bike path.

It remains to be seen what the South Bay and Harbor Area's other power plants will do in light of NRG's action.

Randy Howard, who serves as assistant to the chief operating officer of the DWP's power system, said the agency is still in the process of analyzing impacts and potential mitigation measures for ocean cooling.

"We're still in the study phases," Howard said. "I'm not going to rule out any of the options."

One proposal being studied for Scattergood is a closed-loop cooling system that could share recycled water from the nearby Hyperion Wastewater Treatment Plant, he said.

Brad Scott, who manages the AES plant in Redondo Beach, could not be reached for comment.

It's unclear how NRG's move will affect the city of El Segundo, which is studying whether to rezone the plant's oceanfront parcel for a resort hotel.

Mayor Kelly McDowell said city officials started the process in the event that NRG was unsuccessful in securing the financing needed for the overhaul.

El Segundo wants to ensure that the waterfront site gives the city a guaranteed source of income - whether it be utility-users' taxes or hotel bed taxes, McDowell said.

"We've always been supportive of NRG's efforts to secure a long-term contract," he added.

But as it is today, the plant "is just not reliable as a revenue source," McDowell said. "We just want an insurance policy for a continued source of revenue for the parcel."