Penn State Researchers Are Revolutionizing Solar Panels
High-efficiency solar panels will be coming to a rooftop near you soon, and it’s all thanks to Penn State research. Referred to as concentrating photovoltaic — or CPV — systems, these solar panels operate a much higher efficiency than the standard solar panel.
Until recently, CPVs only existed on a large scale, typically in systems that are about the size of a billboard. Chris Giebink, an assistant professor of electrical engineering at Penn State, has put in work to shrink those down to a more reasonable size for application on a residential level.
“Most solar panels that you see on people’s roofs are made out of silicon or other materials that are about 20 percent efficient. That means that they convert about one-fifth of the sunlight’s energy into electric power,” Giebink said. “You see them everywhere and they work well and their price has decreased dramatically, but more and more there’s a challenge to increase the efficiency and get something substantially higher than that 20 percent.”
That challenge is one that was taken on by a research team that included Penn State and University of Illinois engineers. They were able to vastly decrease the size and manufacturing cost of creating these ultra-efficient solar cells. CPVs concentrate sunlight anywhere from 100 to 1,000 times and they can operate at nearly 50 percent high efficiency than the standard solar panel.
“If you stuck one of these up on your roof and compared it with the state-of-the-art solar panels already out there, you could get 30 to 50 percent more energy over the course of a typical, sunny day,” Giebink said.
While the panels have previously only been implemented in large open areas, like deserts in California, Arizona, and Israel, this project has solved the size issue.
Conventional solar cells for CPVs are a centimeter, while the new cells created through this research are just a few hundred microns — or a few tenths of a millimeter — in size.
In addition to removing size concerns, Penn State engineers have been able to lower the production cost of CPVs by altering the optic technology that tracks the sun. The standard CPV uses a lens that has to tilt throughout the day, adjusting itself to precisely concentrate sunlight on the solar cells.
Now, the cells themselves shift just a centimeter in any direction to follow a focal spot of sunlight. The optics are cheaper, and so are the cells themselves due to advances in their creation process.
“The end result is a CPV panel that achieves a full day’s worth of tracking just by sliding a tiny amount, and from a distance, you can’t tell that they’re moving,” Giebink said. “For all intents and purposes, they behave very similarly to a standard solar panel that somebody puts on their roof.”
Don’t rush to the store to purchase the latest in solar panel technology just yet, though. Giebink said that there is no set timetable for a smaller CPV to hit the market, but he’s optimistic about the getting the panels down to a low price point.
“It’s tough to speculate on cost, because we’re mainly involved in the science, but what I can say is that it has the ingredients to give a low-cost power system,” he said.