Silicon solar cells placed in spheres take advantage of scattered light to make the collection of solar energy flexible even in small devices.
Flat solar panels still face major limitations when it comes to making the most of the available sunlight each day. A new spherical solar cell design aims to increase solar energy harvesting potential from nearly every angle without the need for expensive moving parts to follow the apparent movement of the sun across the sky.
The spherical solar cell prototype designed by Saudi researchers is a small blue sphere that a person can easily hold in one hand like a ping pong ball.
Experiments carried out indoors with a solar simulator lamp have already shown that it can achieve between 15 and 100% more power compared to a flat solar cell with the same total surface area, depending on the background materials that reflect the sunlight. in solar cells.
The research group hopes that its nature-inspired design could perform equally well in future field tests in different locations around the world.
The spherical architecture increases the ‘angular field of view’ of the solar cell, which means that it can collect sunlight from more directions.
Nazek El-Atab, postdoctoral researcher in microsystems engineering at the King Abdullah University of Science and Technology (KAUST).
To create the spherical solar cell design, El-Atab and his colleagues built on their earlier work, which demonstrated how to create thinner and more flexible solar cell designs based on a corrugated groove technique.
Tests with the solar simulator showed that the spherical solar cell provided 24% more power output than a traditional flat solar cell when immediately exposed to sunlight. That power advantage jumped to 39% after both types of solar cells began to heat up and suffered some loss of energy efficiency, indicating that the spherical shape may have some advantages in dissipating heat.
The spherical solar cell also provided 60% more power than its flat counterpart when both could collect only scattered sunlight under a simulated roof instead of receiving direct sunlight.
The Saudi team manufactured the spherical solar cell using monocrystalline silicon solar cells that currently account for almost 90% of the world’s solar energy production.
What surprises me is that the authors have demonstrated in a series of articles the ultra-flexibility that can be achieved with rigid silicon solar cells using the corrugation technique. I am most excited about the ability to make spherical cells.
Zhe Liu, postdoctoral researcher in solar engineering at MIT
Still, spherical solar cells cannot replace traditional solar cell technology in utility-scale solar power plants, according to Liu.
The application of spherical design may seem very limited, but the ability to manufacture commercial silicon solar cells in any form would allow for a wide adaptation of photovoltaic power in autonomous devices, such as IoT (Internet of Things) sensors, and autonomous vehicles. . If we can fully power these autonomous devices with shaped photovoltaic panels, this could be a game changer.
Hussain and his colleagues plan to build and test large arrays of spherical solar cells. And they are already working on new shapes that resemble tents or umbrellas to see if they offer any advantages.
We are going to create spherical cell assemblies for areas from 100 to 1,000 square feet, comparing cost-benefit functionality to traditional cells. We will then deploy it to different geographic locations throughout the year to understand its performance and reliability.
More information: spectrum.ieee.org