Organic photovoltaics make efficiency gain

Organic photovoltaics (OPVs) reached a new milestone this week when Konarka announced that it achieved a world-record 8.3 percent efficiency rating from the National Renewable Energy Laboratory. OPVs are a novel form of photovoltaics (PVs) that are finding a home in portable, flexible applications and also building-integrated applications.

The gains in efficiency are more impressive considering that in May 2009, the world-record for OPV was 6.4 percent efficient, which was also held by Konarka at the time. But OPV still remains far less efficient than other forms of PV—like silicon, which commonly reaches average efficiencies of 14 percent and has been produced at efficiency levels higher than 20 percent.

On the other hand, OPV is flexible, uses less expensive materials to manufacture and can be easily incorporated into fabrics and building-integrated PVs.

“In OPV, the manufacturing process is so much cheaper and greener, and they’re using cleaner materials,” said Tracy Wemett, a spokesperson for Konarka.

The technology continues to face obstacles, however.

For instance, in addition to lower efficiencies, the materials also have a shorter lifespan.

“The goal has always been 10 percent efficiency and a 10-year lifetime,” said Wemett.

For comparison, silicon cells are expected to last at least 25 years. She said the company is close to the first goal, but the material in which the OPVs are encased—a plastic—limits their viable life to about 5 years at this point.

“If you put a different barrier between it, it should last longer,” she said.

At this point, Konarka is focused on getting the technology into more hands, Wemett said.

Konarka is primarily an OPV manufacturer that’s selling the product to other companies for their uses and makes its OPV Power Plastic to customers’ specifications, which include multiple colors. In fact, Konarka has developed camouflaged-patterned materials for use by the military, Wemett said.

Since the materials Konarka uses can also be transparent or semi-transparent, they’re ideal for building-integrated PV applications like windows or curtain walls.

Perhaps the most readily available application of Konarka’s Power Plastics is now found in travel ware, like laptop bags and even personal coolers. Applications that take advantage of the material’s light weight while providing power for laptops or other portable electric devices.

Image courtesy of NREL.