ALBANY - There are high hopes here for an electric transmission cable that can carry three to five times the power of traditional cable.

SuperPower Inc., the maker of the cable, and its partners are optimistic a successful four-year test of the underground, 350-meter long high temperature superconducting cable can prove its usefulness and spur utilities to start installing it.

Officials say the lines can improve transmission efficiency, alleviate problems with power line siting and reduce the environmental impact of traditional cables.

"We're talking about an awesome market potential," SuperPower President Philip Pellegrino said.

Still, many say the industry isn't likely to adopt the product before addressing cost and reliability questions.

In the 1980s, scientists found a new combination of ceramic materials that could conduct electricity without any resistance when cooled to minus 322 degrees Fahrenheit. That temperature is reachable by using liquid nitrogen, which is cheap, abundant and environmentally friendly, unlike the oil used to cool traditional power lines, Pellegrino said.

Officials say superconducting lines could help prevent outages like one in August 2003 that left 50 million people in the United States and Canada without power.

"The blackout would have never gotten to the magnitude it did if we had been routinely reinforcing the transmission lines, over the past 20 years," Pellegrino said.

He says installing superconducting lines will be easier than traditional power lines since they will be underground, eliminating concerns over safety and aesthetics.

The cables' efficiency will also cut the need to produce as much power, thereby reducing the amount of oil, coal or natural gas burned at plants, Pellegrino said.

A report issued by the Department of Energy's National Oak Ridge Laboratory said the country's needs for "reliable and affordable electricity have been seriously challenged over the last decade."

While restructuring has led to increased sales through wholesale power markets and increased generating capacity, "the current transmission infrastructure is incurring higher stresses as demands push system capabilities to their limits."

Jim Owen, a spokesman for the Washington-based Edison Electric Institute, a utility industry group, said while the country's electric system is "among the world's finest," there are still shortcomings.

"Wholesale markets are taxing the system," he said. "It needs to be reinforced and made robust in some parts. We can't rest on our laurels."

The BOC Group, a British-based industrial gas company with its U.S. headquarters in Murray Hill, N.J., sees potential in the superconductors.

BOC and Sumitomo Electric of Japan are partnering with SuperPower, a unit of Intermagnetics General Corp. based in Schenectady, on the $26 million project on Niagara Mohawk's system in Albany. The Energy Department is funding $13 million of the project's cost while New York state is supplying $6 million and the companies are spending $7 million.

BOC is supplying the cryogenic refrigeration.

"There are many potential candidates throughout the world for superconducting cables - Boston, New York, Chicago, L.A.," said Ed Garcia, vice president of process gas ventures at BOC. "We're entering at the ground level. This may change the way electricity is delivered in the U.S. It could be a very large market."

Pellegrino said superconducting cable won't be mass produced until 2007 or 2008, after the major demonstration projects are done and the reliability demonstrated.

American Superconductor, based in Massachusetts, is working on a high-temperature superconductor transmission demonstration project on the Long Island Power Authority's system.

Ultera, a joint venture of Georgia-based Southwire Co. and nkt cables, based in Denmark, plans to conduct a demonstration superconductor project on the American Electric Power grid in Columbus, Ohio in 2005, according to the Southwire Web site.

David Schanzer, a utility analyst with Janney Montgomery Scott LLC, said that for most utilities facing profit pressure from investors to adopt such technology, the price has to be right.

It currently costs about 10 times as much to lay superconductive cable as it does to string copper wire above ground but company officials say the cost should be equal in about five years.

"The cost of some of the new technology is excessive, at least to recover in rate proceedings," he said. "It's probably not going to be immediately embraced by boys in the utility industry. ... They won't undertake anything unless they can show immediate bottom-line savings."

It's a point Pellegrino concedes.

"The utilities want to be the first to be second on new technology," said Pellegrino, a former executive with the New York Power Authority.