Concentrated photovoltaics (CPV) are a technology that generates electricity from sunlight. You probably know that already, but now a team of researchers have worked on enabling CPV systems for rooftop use by combining photovoltaic cells and a 3D printed plastic lens array which not only reduces the size and weight, but also cuts the total cost of such systems.
The researchers discovered that they could reach 70 percent optical efficiency — and they hope to reach 90 percent efficiency — using their design.
“The main benefit of printed optics for CPV is rapid prototyping and testing of initial concepts. The quality of the printed optics is sufficient for proof of concept,” said Noel Giebink, one of the authors of the research and an assistant professor of electrical engineering at Penn State University.
“We partnered with colleagues at the University of Illinois because they are experts at making small, very efficient multi-junction solar cells,” said Giebink. “These cells are less than 1 square millimeter, made in large, parallel batches and then an array of them is transferred onto a thin sheet of glass or plastic.”
Previous tracking systems only functioned about two hours a day as the focal point moved out of the range of the solar cells. The researchers solved that problem and enabled solar focusing for a complete eight-hour period — and with a total movement of approximately 1 centimeter.
One of the arrays, a refractive surface, collimated the light while another which was coated with a reflective material reflects the collimated light onto the micro-cells.
“Current CPV systems are the size of billboards and have to be pointed very accurately to track the sun throughout the day,” Giebink says. “You can’t put a system like this on your roof, which is where the majority of solar panels throughout the world are installed.”
The research was funded by the US Department of Energy.
Do you know of any other ways 3D printing is being used to move energy production systems forward? Let us know in the 3D Printed Lenslets forum thread on 3DPB.com.