This story is from UCLA Today, a discontinued print and web publication.

Increasing energy efficiency through innovation


Imagine limitless portable energy fueling your latest electronic gadget; lightweight power plants supporting mobile military outposts; or semi-transparent window coverings that cool your home by day while storing power to light your living room after dark.

El Monte, Calif.-based Solarmer Energy Inc. is commercializing these and other solar power technologies that were discovered in the lab of Yang Yang, Ph.D., professor of materials science and engineering at the Henry Samueli School of Engineering and Applied Sciences at UCLA. Yang’s research into lightweight plastic solar cells may prove to have a number of practical applications.

"As energy prices soar, solar energy is once again becoming a very important, hot technology," Yang says. "We began our work back in 2001, before the latest surge in prices, so we’re positioned at the leading edge of the current solar power research curve."

Solar power has been recognized as a clean, unlimited source of energy, and the commonly used silicon has semiconductor properties that make it ideal for solar cells. However, the material is too expensive and unwieldy for many applications, which has prevented the industry from growing beyond a bit player in the global energy market.

The solution to these challenges may lie in polymers, the lightweight, low-cost plastics used in thousands of packaging applications and simple, inexpensive products such as insulators, pipes, household products and even toys. Plastic solar cells are made up of a thin sheet of plastic separating two conductive electrodes. Simple and nondescript, they look like black plastic trash bags, Yang says.

The key to commercial success for polymer solar cells lies is boosting efficiency and durability while controlling cost. Traditional silicon solar cells convert 14 percent to 18 percent of solar energy they absorb to useable power. Yang has pushed his plastic solar cells close to the 5% mark, with a goal of 15 percent to 20% useable power-conversion efficiency at as little as one-tenth the cost of silicon-based solar cells. Semi-transparent polymer solar cell technology is another research interest that holds promise for a range of new applications. The team has achieved 85% transparency with power conversion efficiency of 2.8%.

Since May 2006, Solarmer Energy Inc. has licensed seven polymer solar cell patents registered by Yang's lab and is in the process of licensing several other key patents based on his research. Former doctoral students Gang Liand and Vishal Shrotriya, who both worked on polymer solar cell technology as part of Yang's research group at UCLA, now lead product development at Solarmer Energy.

The start-up firm also provides partial financial support for continuing research both on the UCLA campus and at the company's new 6,000-square-foot in-house research and development facility. Support from a UC Discovery grant, the Office of Naval Research and the Air Force Office of Scientific Research (AFOSR) also are contributing fundamental and applied discoveries on polymer use in solar technology.

Yang expects commercial applications of his work to appear first in the consumer electronics industry and later in applications used to power homes, offices, factories and military equipment in the field.

"If we can generate electricity from solar energy at 10% efficiency and 10% of the cost, then we have the capability of turning every single household in the United States into a little power generator."

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