US researchers develop material that can store solar energy for weeks

21 June 2015 (Last Updated June 21st, 2015 18:30)

Chemists at University of California in Los Angeles (UCLA) have discovered a new technology that can store energy from the sun for up to several weeks.

UCLA research solar PV

Chemists at University of California in Los Angeles (UCLA) have discovered a new technology that can store energy from the sun for up to several weeks.

The technology, created through research conducted at the university, has produced findings that were published in the Journal Science.

The innovation was inspired by the way plants generate energy through photosynthesis.

Unlike conventional rooftop solar cells that use expensive silicon, the new technology utilises plastics. Apart from being cost-effective, this enables with well-defined structures similar to those in plants.

UCLA chemistry professor and senior author for the research Sarah Tolbert said: "In photosynthesis, plants that are exposed to sunlight use carefully organised nanoscale structures within their cells to rapidly separate charges, pulling electrons away from the positively charged molecule that is left behind, and keeping positive and negative charges separated.

"Once you make the right structure, you can vastly improve the retention of energy." 

"Modern plastic solar cells don’t have well-defined structures like plants do because we never knew how to make them before.

"But this new system pulls charges apart and keeps them separated for days, or even weeks. Once you make the right structure, you can vastly improve the retention of energy."

UCLA chemistry professor and research co-author Benjamin Schwartz said: "When the charges never come back together, the system works far better.

"This is the first time this has been shown using modern synthetic organic photovoltaic materials."

Researchers are presently working on how to incorporate the environmentally friendly technology into real, effective solar cells.

UCLA chemistry professor and research co-author Yves Rubin said: "When we can put them together and make a closed circuit, then we will really be somewhere."


Image: A new arrangement of solar cell ingredients with bundles of polymer donors (green rods) and neatly organised fullerene acceptors (purple, tan). Photo: courtesy of UCLA.