Putting the sun to work: Student hopes
to make solar panels more efficient © July 9, 2010, Norwich University Office of Communications
Kedaar Raman has read studies suggesting you can increase a solar panel’s efficiency 30 percent simply by washing it.
Dirt, dust, bird droppings and cloudy skies block sunlight and hinder a panel’s ability to convert it into electrical energy. Hailstones and falling debris can harm sensitive photovoltaic cells, diminishing the efficiency of an entire module or array of panels. Yet owners often ignore maintenance needs and aren’t aware when panels are damaged.
Raman, an electrical and computer engineering student at Norwich University, sees this as a significant oversight and an opportunity. Thanks to a fellowship provided by the University, he is devoting his summer to creation of a system that will give owners feedback to know when solar panels, often located on top of buildings or in remote locations, need service. It’s an opportunity he believes is largely ignored by the industry.
“There are no big players in the maintenance market,” said Raman, who is living on the Northfield, Vt., campus of the country’s oldest private military college, where he can concentrate on the project for 10 weeks between his junior and senior years. He is a civilian student who grew up in India and Oman.
Electrical energy is produced when solar radiation is captured by photovoltaic cells—generally made of silicon—and converted into DC current capable of being stored in batteries. Raman is hoping to produce a computer program that runs algorithms capable of detecting signal irregularities within a cluster of solar cells. This would trigger a text message or email to the owner.
His programs would work in conjunction with existing maximum power point tracking [MPPT] controllers, which are electronic devices that monitor energy produced in a solar panel and keep it functioning at maximum levels. To do this, Raman needs to make a thorough study of the signals MPPT devices use. He envisions a program refined enough to give the user specific information about the nature of the problem, and hopes to address factors as detailed as the effect of different types of clouds on panel efficiency.
“That would be an amazing level of detail if you could get it,” he said.
He also needs to thoroughly understand the construction of photovoltaic cells and how they fit together. He has set up in an engineering lab littered with bits and pieces of solar cells and equipment, including an air compressor, toaster oven and soldering iron used to make cells by hand. It is a system created by engineering Prof. Michael Prairie, with whom Raman works closely.
There are no big players in the maintenance market.
~ Kedaar Raman,
on the solar-energy industry
“One of the reasons I picked this project is I can learn from him,” said Raman.
His maintenance alert system is just one piece of the research being conducted by Prairie, whose goal is to improve MPPT controllers—which are generally used with commercial panels—to draw ever-higher levels of power from solar arrays and make them an efficient match with storage devices. By focusing the tracking system on ever-smaller modules of a few cells each, Prairie would diminish the problem of a cluster being affected by a single cell or group of cells, as efficiency is generally determined by the average of cells in an entire panel. Another goal, he said, is to discover the point at which MPPT frees up more power than it uses.
“I want to find that break point where it makes sense to do the control,” said Prairie, a Norwich alum.
Both Prairie and Raman believe engineering students are becoming more aware of green energy, spurred by demands for efficient and renewable sources of power and environmental concerns. Raman said he expects energy efficiency to provide a career, and he hopes people understand the importance of the field as fossil fuels become less accessible and more expensive.
“People need to feel the weight of the times,” he said.
Prairie said photovoltaics will be a small but significant part of our energy future.
“It’s very important, but it’s not everything. I would agree with you there,” Raman responded. “You have to use it in conjunction with other sources.”