Using Recycled Photovoltic Modules and Batteries for Engineering Education, Student Projects, and as Viable Portable, Backup Storage Power Sources
2019 ASEE Annual Conference & Exposition Proceedings
As the efficiencies of new photovoltaic (PV) modules continue to increase, and their purchase prices dramatically decrease, companies and organizations that were early adopters of PV energy sources are now often upgrading their sometimes decades-old PV arrays to the newer, higher efficiency PV systems. The installation of these upgraded PV systems often, unfortunately, result in the older and fully depreciated, but still reasonably functional, PV modules being hastily disassembled (sometimes
... mbled (sometimes destructively), scraped and sent to a landfill. Recently, the Alternative Energy Engineering program at Lawrence Technological University (LTU) received donated, scrapped, and older Isofoton I-94/24 PV modules from Masco Corporation, a local industrial partner of the LTU College of Engineering. In this paper, the faculty and student authors show how these scrapped, but still functional, PV modules can yet have a useful life. The initial performance assessment of each module by the authors using a simple, low-coast variable resistance testing set-up to sort-out working and non-working modules is discussed. Examples of the generated module performance test data are presented. Also reviewed are how these test data, along with Isofoton product literature, were used in the circuit design for their integration with recycled 12-volt lead-acid batteries (available from a previous university project) into a portable, and expandable, back-up, photovoltaic power-source student project. Also, a possible approach for how this integrated system could serve as a prototype for how such recycled modules and batteries might be used for viable energy storage systems in the future is proposed. Lastly, student feedback regarding their experience, knowledge gained, and the benefits they received in participating in this project are documented. Introduction: Lawrence Technological University (LTU or Lawrence Tech) has offered an alternative energy engineering program since 2003, and has been documented previously  . The faculty-author of this paper is the director of that program, and has been since its inception. Due to the high level of student interest, there is always an on-going desire to find appropriate renewable energy projects for students to take on and to participate in for the program. Lawrence Tech also faces the challenge common to all universities of securing funding for such student projects, and making available the faculty time needed to properly supervise and support those projects. High value engineering projects, at low-cost are very desirable. Often corporate donations of equipment and materials help, and using those materials does provide valuable opportunities for students to learn and participate in truly meaningful educational activities. These are the origins of this project. The unique and interesting aspect of this faculty-student project focuses on how it is indeed possible to use older, recycled photovoltaic modules (donated to Lawrence Tech from a partnering company in Southeast Michigan) and several deep-discharge, 12-volt, lead-acid batteries that were available and used on a previous project at Lawrence Tech in 2007, and integrate these into a viable power system. This on-going project is a portable PV powered prototype system with energy storage and various energy outputs. We have now physically demonstrated this integrated system's ability to capture solar energy and convert it to DC power, to deliver 110 volts AC, and both 24 volt DC and 12 volt DC output power in both laboratory and out-door experimental setups. Another important aspect of this project is that the PV power source is expandable. The basic stand-alone cart has two PV modules (at approximately 100watts each), but the design also allows for an additional four more PV modules (yielding to up to ~600 watts total) providing greater solar source power for quicker battery charging, or more daytime external power delivery. The system is also expandable to incorporate additional battery storage. Background: The goal of this on-going project is to design and build a self-contained and portable photovoltaic (PV) power system with on-board electric energy storage batteries using repurposed and recycled materials.