Automated shape-transformable self-solar-tracking tessellated crystalline Si solar cells using in-situ shape-memory-alloy actuation

Abstract

Photovoltaic energy systems in urban situations need to achieve both high electricity production and high capacity in restricted installation areas. To maximize power output, solar-tracking systems tilt solar arrays to track the sun’s position, and typically flat modules are used to maximize the cross-sectional area. Such tracking systems are complex and expensive, and flat modules cannot utilize omnidirectional incident light. For solar systems in urban environments, we have developed two-dimensional (2D) or three-dimensional (3D) tessellated solar-cell modules that use shape transformation, and combine solar tracking and an arch structure for use in restricted areas. The modules can use scattered and omnidirectional incident light. Simply by attaching shape-memory alloy strips to the surface of the solar panels, the shape of the array can be transformed in response to heat from sunlight. Compared to a perfect solar-tracking system, our simulation results indicate that the modules present a large cross-sectional area perpendicular to the direction of sunlight and provide superior tracking performance, resulting in a 60% increase in electricity production over the course of 1 day. In addition, by using different designs for the tessellation units, dome shaped or other 3D structures are possible, for specific applications and to meet aesthetic requirements.

Shape Memory Hybrid Composites

“… 116 Lan et al worked on a shape memory releasing mechanism of smart arrays of solar cells. 117 Figure 25 shows SMA-based automated foldable solar panels that work with the shape memory effect by utilizing heat from solar energy, as developed by Yun et al 118 They worked on tracking solar energy to maximize energy output. Results from simulations show a large cross-sectional area perpendicular to sunlight, providing a 60% increase in electricity production over 1 day.…”

“… (a) Photographs of the transformation process of rectangular and equilateral triangular solar cells from folded to flattened configuration. Photograph courtesy of Yun et al 118 Copyright 2022. …”

Kirigami enabled reconfigurable three-dimensional evaporator arrays for dynamic solar tracking and high efficiency desalination

“…Kirigami has enabled various reconfigurable devices for soft robots (22,23), wearable electronics (24,25), and energy harvesters (26), among others (27)(28)(29). Recently, kirigami/origami designs were exploited for the engineering of solar trackable photovoltaics (30)(31)(32)(33)(34), suggesting a route for designing ISEs with dynamic configurations. Nevertheless, the complex mass transfer processes involved in solar evaporation would require distinct considerations on structural design and materials configuration.…”

Orientation and Exposure Efficiency of a Solar Tracking Surface in Clear Sky

“…Passive solar tracking systems use non-expensive materials that are thermally active, which means that they can expand with the temperature change, rotating a surface of the panel perpendicularly to the sun. There are available technologies utilizing liquid freon [9], aluminium [10] or other shape memory materials [11,12]. This system is simple in operation and does not rely on any mechanical actuators, what makes it very economic.…”