The sea otters at the Aquarium of the Pacific are always a big draw, delighting visitors with their antics in the water.

What visitors don’t realize is the otter exhibit is also a showcase for energy efficiency.

As part of its greening of the aquarium initiative, the Long Beach tourist attraction replaced existing lighting in the otter exhibit with energy-efficient LED lights.

The difference is not apparent to the uninitiated, but it is one of the efforts that has helped the aquarium reduce its carbon footprint by 25 percent since 2007, even as attendance has grown to 1.5 million visitors a year.

Part of the motivation for the greening initiative was for the aquarium to be a model of environmental stewardship, but it was also a practical matter.

“Energy is a big part of our costs,” said John Rouse, vice president of aquarium operations. He noted that at its peak, the aquarium’s electric bill was $2 million a year.

The challenge for the aquarium was to install equipment and modify operations in a way that wouldn’t affect visitors or the 12,000 animals.

Working with Southern California Edison and several vendors, the aquarium gradually improved its energy savings.

They reprogrammed the central plant so the chilled water used to cool the water tanks and for air conditioning wasn’t being over-pumped — a move that saved 800,000 kilowatt-hours a year. Lightbulbs were replaced by LEDs. A total of 46 kilowatts of solar panels were installed in three locations. New skylights and solar tubes maximized the use of natural light. Next year, they plan to install three fuel cells.

The aquarium also participates in SCE’s demand response program, reducing its electricity usage in periods of high demand.

Water conservation also has been a high priority at the aquarium. New dual flush toilets, waterless urinals and touch-free sensor faucets have saved 960,000 gallons of water a year. A drought-tolerant garden was also installed as well as drip irrigation and a weather-based irrigation controller.

In recognition of its efforts, the aquarium was one of 11 SCE business customers recently recognized with a 2015 Cool Planet award. The award, jointly sponsored by SCE and The Climate Registry, is given to customers who demonstrate leadership in energy savings and a reduction in greenhouse gas emissions.

“This gives us a chance to say thank you to an outstanding group of customers for implementing projects that save energy, money and our environment,” said Lisa Cagnolatti, SCE vice president of the Business Customer Division, during the recent Cool Plant awards ceremony at the aquarium.

SCE also received recognition that day when Long Beach Mayor Robert Garcia presented the utility with a city proclamation for its environmental efforts.

“You don’t hear some of the positive work Edison does,” said Garcia. “They do a lot of environmental work and I want to thank them.”