A team of MIT researchers have revisited the standard way solar panels are constructed and have developed a new structure that maximizes the capture of sunlight.
Cubes or towers that extend the solar cells upward in three-dimensional configurations. Amazingly, the results from the structures they’ve tested show power output ranging from double to more than 20 times that of fixed flat panels with the same base area.
The biggest boosts in power were seen in the situations where improvements are most needed: in locations far from the equator, in winter months and on cloudier days. The new findings, based on both computer modeling and outdoor testing of real modules, have been published in the journal Energy and Environmental Science.
“I think this concept could become an important part of the future of photovoltaics,” says the paper’s senior author, Jeffrey Grossman, the Carl Richard Soderberg Career Development Associate Professor of Power Engineering at MIT.
The time is ripe for such an innovation, Grossman adds, because solar cells have become less expensive than accompanying support structures, wiring and installation. As the cost of the cells themselves continues to decline more quickly than these other costs, they say, the advantages of 3-D systems will grow accordingly.
“Even 10 years ago, this idea wouldn’t have been economically justified because the modules cost so much,” Grossman says. But now, he adds, “the cost for silicon cells is a fraction of the total cost, a trend that will continue downward in the near future.” Currently, up to 65 percent of the cost of photovoltaic (PV) energy is associated with installation, permission for use of land and other components besides the cells themselves.
For an accordion-like tower — the tallest structure the team tested — the idea was to simulate a tower that “you could ship flat, and then could unfold at the site,” Grossman says. Such a tower could be installed in a parking lot to provide a charging station for electric vehicles, he says.
Photo: Allegra Boverman- Two small-scale versions of three-dimensional photovoltaic arrays were among those tested by Jeffrey Grossman and his team on an MIT rooftop to measure their actual electrical output throughout the day.