When it comes to boosting efficiency in solar panels—that is, increasing the amount of the sun’s energy each photovoltaic cell can harness—researchers have tried a lot of tricks. Many solar power systems are equipped with tracking devices that enable the solar panels to follow the sun, changing their angle so they are always attracting a maximum amount of solar energy. Now, researchers have developed a special glass coating for solar cells that capture sunlight from almost any direction and increase efficiency by as much as 46 percent. As an added bonus, the coating also repels dust, meaning the solar panels stay cleaner much longer than traditional panels.
This finding comes from researchers at King Abdullah University of Science & Technology (KAUST) in Saudi Arabia and Taiwan’s National Central University and was recently published in ACS Nano. Experts in the solar power industry haven’t been able to agree on the ideal direction solar panels should face for maximum efficiency—west or south. That debate has spurred researchers to look for ways to make solar panels more efficient no matter which way they are pointing. This new glass coating is composed of ultrathin nanorods and honeycomb nanowalls that make it possible for the solar cells to harvest the sun’s energy from multiple angles. That capability yields a boost of 5.2 to 27.7 percent in cell efficiency, depending on the angle of the light. Researchers believe the efficiency enhancement could be up to 46 percent during long-term use.
Directional choices are one factor in solar energy conversion efficiency, and another is dirt. Traditional solar panels, no matter how efficient their materials or placement, collect dust which diminishes their efficiency. That means they have to be cleaned on a regular basis in order to collect and convert the sun’s energy into usable electricity. (If you saw The Martian, this information isn’t news to you.) Because the glass coating repels dust by nature, these new solar panels don’t need as much special attention in that department. In fact, tests showed that the solar panels with the glass coating worked “outdoors at optimum levels for six weeks while the efficiency of panels with an unmodified coating dropped over the same period.”
Images via Shutterstock and Chin-An Lin, et al.