波士顿大学电力和电脑工程学院在240届美国化学协会国际会议上展示了其自动清洁光伏组件产品。在会议中，该学院研究人员展示了如何使自动清洁涂层覆盖着太阳能电池上——基于该学院在火星空间任务的科技开发——能够大幅提高组件在阳光下的电力转换率。而对于大型的光伏系统其维护费用也将会大幅降低。
该学院的学术领导人马雷 K 曼祖德和他的波士顿大学同事们，最初的研究开发项目是月球和火星认为上的太阳能组件自净科技。火星本身就是一个充满了尘土的干燥星球。但是我们发往火星上的探测车光伏组件以及机器人系统都必须保证不被这些尘土干扰。同样的在地球上也是一样，光伏组件必须不被周围的尘土所覆盖。
这种自净科技是将一层透明的光敏感性强的涂层材料沉积在玻璃或者透明塑料板上。感应尘土在组件面板上的堆积程度当尘土的集中达到一定程度时，涂层就会利用电力发出一种波动来驱除组件表面的尘土。将尘土从组件边缘抖动下去。曼祖德说这个过程将持续两分钟。而且该过程将使组件摆脱大约90%的尘土。而在清洁过程中只需要从组件中获取少量的电就可以满足过程中的能源需求。
Self-cleaning technology from Mars can keep terrestrial solar panels dust-free
Research scientists from Boston University's Department of Electrical and Computer Engineering have presented their findings on self-dusting solar panels to the 240th National Meeting of the American Chemical Society (ACS). During the meeting, they described how a self-cleaning coating on the surface of solar cells - based on technology developed for space missions to Mars - could increase the efficiency of producing electricity from sunlight. Maintenance costs for large-scale solar installations could also be reduced.
Working with NASA, study leader Malay K. Mazumder, Ph.D and colleagues, from Boston University, initially developed the self-cleaning solar panel technology for use in lunar and Mars missions. “Mars of course is a dusty and dry environment,” Mazumder explained, “and solar panels powering rovers and future manned and robotic missions must not succumb to dust deposition. But neither should the solar panels here on Earth.”
The self-cleaning technology involves deposition of a transparent, electrically sensitive material deposited on glass or a transparent plastic sheet covering the panels. Sensors monitor dust levels on the surface of the panel and energize the material when dust concentration reaches a critical level. The electric charge sends a dust-repelling wave cascading over the surface of the material, lifting away the dust and transporting it off of the screen's edges. Mazumder said that within two minutes, the process removes about 90 percent of the dust deposited on a solar panel and requires only a small amount of the electricity generated by the panel for cleaning operation.
He added: “A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40 percent. In Arizona, dust is deposited each month at about four times that amount. Deposition rates are even higher in the Middle East, Australia, and India.”
The current market size for solar panels is about USD$24 billion, Mazumder continued. “Less than 0.04 percent of global energy production is derived from solar panels, but if only four percent of the world's deserts were dedicated to solar power harvesting, our energy needs could be completely met worldwide. This self-cleaning technology can play an important role.
“We think our self-cleaning panels used in areas of high dust and particulate pollutant concentrations will highly benefit the systems’ solar energy output. Our technology can be used in both small- and large-scale photovoltaic systems. To our knowledge, this is the only technology for automatic dust cleaning that doesn’t require water or mechanical movement.”
Mazumder added that the need for that technology is growing with the popularity of solar energy. Use of solar, or photovoltaic, panels increased by 50 percent from 2003 to 2008, and forecasts suggest a growth rate of at least 25 percent annually into the future. Fostering the growth, he said, is emphasis on alternative energy sources and society-wide concerns about sustainability (using resources today in ways that do not jeopardize the ability of future generations to meet their needs).
