Fractal solar cell array for enhanced energy production: applying rules underlying tree shape to photovoltaics

Abstract

Plants and photovoltaics share the same purpose as harvesting sunlight. Therefore, botanical studies could lead to new breakthroughs in photovoltaics. However, the basic mechanism of photosynthesis is different to semiconductor-based photovoltaics and the gap between photosynthesis and solar cells must be bridged before we can apply the botanical principles to photovoltaics. In this study, we analysed the role of the fractal structures found in plants in light harvesting based on a simplified model, rotated the structures by 90° and applied them to fractal-structured photovoltaic Si solar cell arrays. Adoption of botanically inspired fractal structures can result in solar cell arrays with omnidirectional properties, and in this case, yielded a 25% enhancement in electric energy production. The fractal structure used in this study was two-dimensional and symmetric; investigating and optimizing three-dimensional asymmetric fractal structures would further enhance the performance of photovoltaics. Furthermore, this study represents only the first step towards the development of a new type of photovoltaics based on botanical principles, and points to further aspects of botanical knowledge that could be exploited, in addition to plant fractal structures. For example, leaf anatomy, phyllotaxis and chloroplastic mechanisms could be applied to the design of new types of photovoltaics.

Application of a c‐Si Solar Cell with a Three‐Dimensional Structure to Indoor Photovoltaics

“…The ratio between the perimeter and surface area (r ps ) determines the size effect under LED lighting conditions. [30] A high r ps value indicates that there are more defects and recombination sites at the cut edge than the generation site, as shown in Figure 3c; the low light intensity restrained the generation rate of electrons, as confirmed by the relative power output. In addition, we examined the effect of the LED configuration on the light intensity, without the scattering sheets.…”

“…From our previous work, compared to a flat cell, a 3-D solar cell structure is better able to accommodate large variations in the angle of incident light, to collect the maximum amount of light for optimal power generation. [29,30] In an office setting, multiple artificial light sources are commonly used throughout the workspace. To evaluate the lighting conditions, it is necessary to determine the number of light To simulate an indoor setting, single (0°), double (0°, 45°), and triple (−45°, 0°, 45°) LED sources were positioned in a periodic configuration, as shown in Figure 2a-c, according to the fraction of diffuse light required (range: 0-1; interval: 0.2), as shown in Figure S1a (Supporting Information).…”

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

“…To calculate the effect of light intensity, a single diode model was used, based on parameters obtained from fitting the voltage-current density curves measured for the PERC cells used in this study. The effect of the AOI on PERC-type solar cells was obtained from our previous work 16 , 18 . Combining the effects of the cross-sectional area, the AOI and the light intensity, Fig.…”

Performance Comparison of Fast, Transparent, and Biotic Heaters Based on Leaf Skeletons

“…[32] Fractal designs also facilitate the efficient collection of electrical and thermal energy and therefore these have been used in different applications such as photovoltaics, sensors, etc. [33][34][35] Fractal-based designs are also advantageous in the field of flexible electronics as this overcomes the limitations of the conventional planar designs by maximizing the surface area at the microscale or, more specifically, maximizing the surface-area-to-volume ratio via simple scaling.…”