New Solar Cell "Most Efficient Ever"

solar cell
Scientists have created a solar cell device that is significantly more efficient than conventional photovoltaic cells.

For the first time, scientists have produced a photovoltaic (PV) cell with a conversion efficiency of 40.7 percent, the U.S. Department of Energy (DOE) reported on December 7. The collaboration of DOE and Spectrolab, Inc. (a subsidiary of Boeing) led to the achievement of a decades-long goal: to break the 40-percent efficiency barrier on solar cell devices. “We are eager to see this accomplishment translate into the marketplace as soon as possible,” Alexander Karsner, assistant secretary for energy efficiency and renewable energy at DOE, said.

The breakthrough cell was developed using a structure called a “multi-junction solar cell.” In this type of device, individual PV cells are made of layers, and each layer captures a portion of the sunlight reaching the cell. This allows the unit to capture energy from a greater range of the solar spectrum, leading to higher efficiency. According to Dr. Richard King, a principal investigator at Spectrolab, “The excellent performance of these materials hints at still higher efficiency in future solar cells.”

According to Spectrolab, the highly efficient units allow for the use of fewer cells overall to achieve the same power output as conventional silicon cells. As a result, the technology may allow for lower PV system installation costs, at $3 per watt, and electricity production costs of $0.08–$0.10 cents per kilowatt-hour. The acheivement has the greater potential of helping to reduce the U.S. reliance on imported oil and increase national energy security, DOE’s Karsner notes.

This story was produced by Eye on Earth, a joint project of the Worldwatch Institute and the blue moon fund. View the complete archive of Eye on Earth stories, or contact Staff Writer Alana Herro at aherro [AT] worldwatch [DOT] org with your questions, comments, and story ideas.