Residential rooftops make up about 85 percent of solar panel installations in the U.S., according to a report from the Department of Energy, but these roofs would need significant reinforcing to support the weight of conventional sun-tracking systems. A team of engineers and an artist developed an array of small solar cells that can tilt within a larger panel, keeping their surfaces more perpendicular to the sun’s rays.
Max Shtein, an associate professor of materials science and engineering at the University of Michigan worked with paper artist Matthew Shlian, a lecturer in the school of art and design, and developed an array of small solar cells that can tilt within a larger panel, keeping their surfaces more perpendicular to the sun’s rays. By designing an array that tilts and spreads apart when the sun’s rays are coming in at lower angles, they raise the effective area that is soaking up sunlight.
Although the team tried more complex designs, the simplest pattern worked best. With cuts like rows of dashes, the plastic pulled apart into a basic mesh. According to the team’s simulations of solar power generation during the summer solstice in Arizona, it is almost as good as a conventional single-axis tracker, offering a 36 percent improvement over a stationary panel.
The design with the very best solar-tracking promise was impossible to make at U-M because the solar cells would be very long and narrow. Scaling up to a feasible width, the cells became too long to fit into the chambers used to make the prototypes on campus, so the team is looking into other options.
“We think it has significant potential, and we’re actively pursuing realistic applications,” said Shtein. “It could ultimately reduce the cost of solar electricity.”
The paper on this work is titled “Dynamic kirigami structures for integrated solar tracking.” The study was funded by the National Science Foundation and NanoFlex Power Corporation.
The University of Michigan has applied for a patent and is seeking partners to bring the technology to market.
Solar cells capture up to 40% more energy when they can track the sun, but conventional trackers are too bulky for most rooftops. Now, by borrowing from kirigami, the ancient Japanese art, researchers are developing solar cells that may expand efficiency while lowering the weight.
About the Collaborators:
Max Shtein, Associate Professor of Materials Science and Engineering, focuses on the science, processing, and application of functional organic and hybrid materials for electronics / optoelectronics, including lighting, displays, photovoltaic and thermal energy conversion devices. His work combines rigorous computer modeling validated by experiments, spanning fundamental and applied research topics.
Matt Shlian is a paper engineer, scientist, artist and lecturer at the University of Michigan in Ann Arbor whose paper work has inspired as much as his talks at TEDxUofM, Ignite and elsewhere.