Spherical Solar Cells Soak Up Scattered Sunlight

An anonymous reader quotes a report from IEEE Spectrum: Flat solar panels still face big limitations when it comes to making the most of the available sunlight each day. A new spherical solar cell design aims to boost solar power harvesting potential from nearly every angle without requiring expensive moving parts to keep tracking the sun’s apparent movement across the sky. The spherical solar cell prototype designed by Saudi researchers is a tiny blue sphere that a person can easily hold in one hand like a ping pong ball. Indoor experiments with a solar simulator lamp have already shown that it can achieve between 15 percent and 100 percent more power output compared with a flat solar cell with the same total surface area, depending on the background materials reflecting sunlight into the solar cells. The research group hopes its nature-inspired design can fare similarly well in future field tests in many different locations around the world. Testing with the solar simulator lamp showed that the spherical solar cell provided 24 percent more power output over a traditional flat solar cell upon immediate exposure to sunlight. That power advantage jumped to 39 percent after both types of solar cells had begun to heat up and suffered some loss in power efficiency — an indication that the spherical shape may have some advantages in dissipating heat. The spherical solar cell also delivered about 60 percent more power output than its flat counterpart when both could collect only scattered sunlight under a simulated roof rather than receiving direct sunlight. Additional experiments with different reflective backgrounds — including an aluminum cup, aluminum paper, white paper, and sand — showed that the hexagonal aluminum cup background helped the spherical solar cell outperform the flat solar cell by 100 percent in terms of power output. The new work is detailed in a paper submitted for review to the journal MRS Communications.