The Solar-Powered Lamp That Failed : Lighthouse: Technology didn’t do the job for the Los Angeles Light. So now the beacon for mariners will go back to light bulbs, albeit some powerful ones.

For more than three-quarters of a century, the Los Angeles Harbor lighthouse has served as a beacon to mariners, its green revolving lantern guiding them safely toward the breakwater that separates the city’s bustling port from San Pedro Bay.

Two years ago, in what was heralded as a first for California, the historic seamark gave in to modernization. Solar panels were bolted to its decks, its graceful 300-pound glass lantern was replaced with a 30-pound plastic version, and Los Angeles Light, as it is officially known, became the first lighthouse in the state to rely on the sun as its source of energy.

Trouble was, it didn’t work--at least not well enough. So now Los Angeles Light is taking a technological step back.

By the end of January, teams of Coast Guard electricians and maintenance men will have cranked up its now-dormant generators in what will be another first: the first lighthouse in the United States to be converted back from solar power to a traditional energy source.

“The system out there was an experimental system,” explained Lt. John Brooks of the Coast Guard’s Aids to Navigation Division in Washington. “What we found is it didn’t have quite enough oomph.”

Coast Guard officials in Long Beach said they have been evaluating the solar-powered light since its installation in September, 1987, and have declared it “unsatisfactory”--neither as bright nor as far-reaching as the old one.

Whereas the old flashing beam could be detected at a range of 19 nautical miles (nearly 22 statute miles) on a clear night, the range for the solar-powered light is only 16 nautical miles in perfect weather, said Lt. Mike Van Houten, assistant chief of the Long Beach Office of Aids to Navigation.

And the lesser intensity prompted mariners to complain that they could not distinguish Los Angeles Light from the many background lights in the congested harbor area.

“It’s not sufficient,” said Capt. Jackson Pearson, who as chief pilot for the Port of Los Angeles is in charge of 15 steersmen who direct ships in and out of the harbor. “We complained about it. It was difficult for the ships to see as a landmark.”

The stately black-and-white lighthouse, 73 feet tall with curved diamond-shaped windows that encircle its lantern, sits at the end of a 2-mile-long breakwater that stretches from Cabrillo Beach in San Pedro to Angels Gate, the mouth of the harbor.

Its distinguishing characteristic is its green light, according to Pearson, who said the colored lamp was installed when the lighthouse was built 78 years ago so that mariners could distinguish it from the white lights of the oil field at Signal Hill.

The lighthouse, which is no longer manned, is also the largest on the California coast, according to retired Coast Guard Rear Adm. Richard A. Bauman, a lighthouse buff from Virginia who visited all 36 California lighthouses in May.

“Most lighthouses are made so that the (keepers) lived in houses alongside them,” Bauman said. “This one was made big enough to provide the living quarters, and there isn’t another lighthouse on the California coast that has the same function.”

For years, Los Angeles Light was powered by an electrical cable that snaked through the breakwater from the lighthouse to the shore. But the cable snapped during severe winter storms in 1982 and, deemed unreliable, was never replaced. For the next five years, the lighthouse operated on its backup generators, which run on diesel fuel.

In the hope that it could save money and help the environment, the Coast Guard decided to try solar power instead. According to Brooks, generator-powered lighthouses create more pollution and are three times as expensive to operate and maintain as those that rely on the sun.

Thus the Coast Guard has been switching from generators to solar power wherever it can. Almost 15,000 of its 16,000 buoys and minor lights--those with a range of less than 10 miles--now rely on solar energy, Brooks said.

Although the conversion program thus far has focused primarily on minor lights, Brooks said 30 of the nation’s 450 working lighthouses have been converted to solar power, including Los Angeles Light and one other in California, the Mile Rocks lighthouse near San Francisco.

Solar-powered lighthouses work best in areas where a shorter range and less intense light are sufficient. Brooks said all the conversions--most of them in New England and the Great Lakes region--have been successful except the one in Los Angeles. Lighthouses that have not been converted either operate efficiently on shore power or require more energy than the sun can provide, he said.

Brooks and other Coast Guard officials say that it is impossible to increase the brightness of Los Angeles Light using solar power--the technology doesn’t exist.

But they won’t be going back to the beautiful old glass lantern. That was recently donated to the Los Angeles Maritime Museum in San Pedro, where excited volunteers intend to put the brass base and two clamshell-shaped, French-made lenses back together for display.

“Hopefully, it will be sitting in a window where you can see it coming down 6th Street,” said volunteer I. Roy Coats as he stripped the base of black paint. “It will be turning and burning all night. That’s what we have in mind.”

Out in the harbor, meanwhile, Los Angeles Light will burn with a more modern, 250-pound version of the old glass lamp. The new lantern will use 1,000-watt bulbs instead of the 75-watt bulbs in use now, and should be visible for 20 miles in clear weather.

There are no immediate plans to restore shore power to Los Angeles Light, although Van Houten said that may happen. He added the failure of solar power in Los Angeles will not keep the Coast Guard from trying it elsewhere in California.

“We have used the same application at Mile Rocks and it has worked well there,” he said. “I think we are making progress. Maybe we’re a little bit ahead of time with this one.”