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Dr. Diana-Andra B. T.

Department of Mechanical Engineering, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy NY USA

 

Talk Title
Performance of Wedge-Shaped Luminescent Solar Concentrators Employing Phosphor Films

Talk Abstract
 

Luminescent solar concentrators (LSCs) have shown potential as a cost-effective alternative to conventional solar panels. They consist of a transparent plastic sheet incorporating absorbing-emitting materials with solar cells attached to the edge(s). Light is concentrated and guided to the edge(s) through internal reflection and red-shifted due to luminescent emission. LSCs have shown the ability to accept light effectively at a variety of incidence angles without the need for tracking systems.

This work investigates the performance of wedge-shaped LSCs of varying aspect ratio (i.e. wedge’s length to its hight) employing inorganic luminescent phosphors.  We demonstrate enhanced performance at incidence angles that conventional solar panels fail to utilize effectively. This behavior is proved experimentally through the measurement of current-voltage (I-V) characteristics of solar cells attached to wedge-shaped LSCs illuminated at representative angles covering the entire range of possible insolation conditions.

The wedge LSCs were constructed using a support made of folded sheet, to which a mirror tape, a phosphor film, silicone, and a solar cell were added. All inner surfaces of the support were lined with 3M enhanced specular reflector. On the bottom surface, a thin phosphor film (green phosphor HTG540, from phosphortech.com) was placed on top the the mirror layer. A c-Si solar cell encapsulated in polycarbonate was then attached to the support forming the light-collection edge of the wedge structure. The cavity formed was then filled with silicone (Sylgard 184 from Dow Corning). Five different LSCs were fabricated. The height was kept at 7 mm (equal to the height of the solar cell)  for all, while the length was 15, 30, 40, 50 and 60 mm, respectively. Tests were carried out using a large area, full spectrum solar simulator with 5% beam uniformity (model 92193 from Newport). At moderate to high polar angles (20-75° from the surface normal), solar cells within wedge-shaped LSCs significantly outperform a solar cell alone. The highest power generated was measured at a polar angle of 40° for a 30mm long wedge-shaped LSC. This power was 76% higher than that produced by the solar cell alone. Furthermore, a maximum efficiency of 8.57% was recorded for the LSC with a length of 15mm, at a polar angle of 30°. Taking into account all polar angles and azimuthal angles, the wedge-shaped LSC with a length of 30mm yielded an average power ratio of 1.09. However, taking the average of all azimuthal angles for polar angles of 30-60°, it yielded an average power ratio of 1.27. This demonstrates the ability of wedge-shaped LSCs to enhance solar cell production relative to conventional solar panels at high polar angles. This supports the deployment of wedge-shaped LSCs onto vertical surfaces to benefit from the effect of higher polar angles throughout the day. Additionally, the enhanced performance of a solar cell within a wedge-shaped LSC at increasing azimuth shows the potential of these devices to operate effectively without the need for expensive tracking systems.

Short Biography

Diana-Andra Borca-Tasciuc is an associate professor in the Department of Mechanical, Aerospace and Nuclear Engineering at Renssleaer Polytechnic Institute (RPI). Her research interests are in energy transport and conversion and micro and nanosystems, covering a broad range of applications including solar energy conversion, power harvesting, thermal management, solid state energy conversion and biomedical applications. She is the recipient of NSF CAREER award and Fulbright Fellowship, as well as RPI’s School of Engineering Research Excellence and Classroom Excellence awards. She has co-authored more than 100 peer-reviewed poublications and is the co-inventor on two international patent applications.

 
Talk Keywords
Luminescent solar concentrators, phosphor, wedge-shape, solar cell.
 
Target Audience
Engineering students, post-doctoral researchers, industry and national laboratories researchers, professors
 
Speaker-intro video
TBA 
 

The International Conference on Innovative Applied Energy (IAPE’18)