Date: Thursday, October 31, 2024

Time:  Noon to 1:10 PM

Location: CHTM, Room 101 and Zoom

Speaker:

Mx. Duncan McGraw of Prof. Tito Busani's Research Group
UNM ECE/CHTM

Abstract:

Agrivoltaics is a burgeoning field of research to maximize the potential of farmland in both generating photovoltaic power and providing high-quality crops. Some key barriers to the expansion of agrivoltaics are the limitations of shade control that come with conventional PV modules due to the close spacing of solar cells, which then requires large spaces between rows of PV modules and reduces the power collection area of the installation, as well as high installation costs. We propose a semi-transparent bifacial silicon solar module using thermoplastics in place of glass to mitigate these issues. This module would incorporate intentional gaps between opaque solar cells to allow for partial transmission of light to the ground. A shading simulation was developed within MATLAB to estimate the fractional solar irradiance (FSI) and photosynthetic photon flux density (PPFD) received within a 50 m2 region including and surrounding the panel with 0.0625 m2 resolution. A mock agrivoltaic installation was constructed on the roof of UNM’s biology building to compare the growth of kale and lettuce under plexiglass sheets covered in aluminum tape in a configuration where the module had 0, 50 or 100% cell coverage.  Following the development of this simulation, prototype 4 solar cell 5x5” thermoplastic modules were fabricated as a proof of concept utilizing a dual-top sheet design to have the uppermost layer experience various forms of environmental degradation related to UV radiation, humidity and heat as a sacrificial layer that could be removed upon significant deterioration. These prototype modules will be exposed to UV and damp heat exposures in three-month equivalent intervals up to 1 year and adapted forms of the IEC 61215 static and dynamic mechanical load tests. Parameters such as the average optical transmission in the visible range (400-700 nm), debonding force, open-circuit voltage (Voc), short-circuit current (Isc), max power point (Pmpp) and fill factor (FF), along with the UV dosage, damp heat exposure time, mechanical pressure applied and number of cycles, will be used to train a Gaussian process regressor to predict the final characteristics of the module as well as the optimal time to remove the top layer.

Biography:

Duncan McGraw (they/them) is a 5th year PhD candidate in the Optical Science and Engineering program at the University of New Mexico in Albuquerque, NM (unceded Puebloan and Piro land). They were born and raised in Kansas City, MO (unceded Kaw / Kansa, Osage, Kickapoo, Otoe-Missouria and Očhéthi Šakówin land) and attended the University of Kansas from August 2016-May 2020, graduating with a BSc in physics. They then joined the Optical Science and Engineering PhD program at the University of New Mexico beginning in June 2020 and obtained their MSc degree in Optical Science and Engineering in May 2023. In their time as a researcher in undergraduate and graduate programs, they have had experience with a variety of disciplines including experimental particle physics, laser cooling of solids as well as photovoltaics, helping them to bring many different perspectives into their work. Their current research focuses on the development of a novel thermoplastic-reinforced agrivoltaic bifacial semi-transparent silicon solar panel.