Janet Gunter has lived in San Pedro long enough to remember when the skies would darken after sunset. Now, after 40 years of development at the ports of Long Beach and Los Angeles, Gunter has to use heavy curtains to block the ambient light that washes in from the sea.

“The visuals — while entertaining when you want to be awake — are a problem if you’re trying to get some sleep,” Gunter said.

Light pollution — or misdirected light — has become an international concern, with groups like the International Dark-Sky Association raising alarms about artificial light’s negative effects on the environment and the circadian rhythms of humans.

To address the problem, port operators and Southern California Edison are preparing to test a new light technology that promises to cut energy consumption in half.

The new lights use a system of metallic reflectors that more effectively direct light particles. The fixtures rely on small, high-intensity bulbs filled with electrically charged gas, or plasma, considered the fourth state of matter, after solid, liquid and gas.

“It’s like a Tic Tac or a Tylenol on steroids,” said Brad Lurie,CEO of Bright Light Systems, the Georgia-based company behind the light-emitting plasma, or LEP, technology.

LEP is similar to LEDs, or light-emitting diodes, in that both are about 50 percent more efficient than high-pressure sodium bulbs traditionally used for industrial and street lighting — the ones that emit a fuzzy orange halo.

LEDs lose their effectiveness the further they are away from the area that needs lighting, which is an issue at the ports, where light poles have to be as high as 140 feet to illuminate the pathways between stacks of containers.

To achieve that kind of range, operators have to turn up the voltage on the LEDs or add more diodes, which reduces the light’s efficiency.

The other advantage of plasma is the quality of the light, which is closer to full spectrum sunlight than white LED light.

Bright Light Systems’ tall-pole units are used in ports, railroads, military bases and airports around the world. Caltrans and the state Department of Corrections and Rehabilitation have expressed interest.

“With plasma, you can tell the difference between a prison guard and an inmate,” Lurie said. “It’s full HD, full color.”

For an additional cost, the light fixtures can be fitted with a wireless transmitter that allows port operators to dim lights during off hours to a sixth of their full power, compounding the energy savings.

SSA Marine, a port operator in Long Beach, plans to conduct a pilot test comparing an LEP tall pole with one that uses LEDs. If plasma stands up to the test, Southern California Edison may certify the technology for energy-saving rebates, as it does for LED technology.

Even without rebates, Bright Light Systems said that, given California utility rates, the cost of the lights is made back in energy savings within three years.

Paul Maltese, an engineer and security officer at SSA Marine, said he was excited about the promise of the technology, but noted that the company will wait for the test results before spending close to $2 million for a new lighting system.

“They can throw out all the numbers they want, but until you have a person under the fixture, you really don’t know how well you can see in that light,” he said. “We’ll let the cards fall where they may.”