Spectrolab Inc. announced Wednesday it had set a world record with a new solar cell able to convert a whopping 29 percent of the sunlight that strikes it into electricity for power-hungry spacecraft.

Records in the competitive field have not lasted long as of late: in laboratory testing, the new radiation-hardened space cell surpassed the previous record of 27 percent efficiency, announced in April. As recently as 1995, solar cell efficiency languished at 19 percent.

"This critical breakthrough for Spectrolab brings us closer to our ultimate goal of manufacturing solar cells with an average efficiency of 30 percent by 2001 and 35 percent by 2003," said Nasser Karam, director of advanced programs and optoelectric products for the Sylmar, Calif. company. Research and development of the cell was partially funded by the Air Force Dual Use Science and Technology Program.

Spectrolab already holds the efficiency record for cells destined for use on Earth, which do not have to withstand the rigors of space. In October 1999, those cells reached 32.3 percent efficiency in lab tests.

Spectrolab said the new space cells would go into production during the third quarter of this year. (Manufacturer Emcore Corp. announced June 27 that it is already producing and shipping triple-junction solar cells that operate at 26 percent efficiency, a benchmark also reached by Tecstar Inc.)

"Spectrolab is and ought to be excited about being able to produce 29 percent efficiency cells," said George Douglas, a spokesman for the National Renewable Energy Laboratory in Golden, Colo. "Thats a huge leap."

With increased efficiency, satellite manufacturers can shrink the size and mass of solar arrays. The gains also allow large boosts in the generating capacity of satellites: Spectrolab hopes to start producing satellite solar arrays capable of generating power outputs anywhere from 20 to 30 kilowatts. A typical suburban home, in contrast, can manage nicely on 4 kilowatts.

Worldwide, shipments of photovoltaic cells for use on Earth and in space totaled 150,000 kilowatts in 1998, the most recent year for which figures are available. That number grows an estimated 20 percent a year.

However, arrays destined for space make up only a tiny percentage of the total, Douglas said.