Intensive research around the world has focused on improving the performance of solar photovoltaic cells and bringing down their cost. But very little attention has been paid to the best ways of arranging those cells, which are typically placed flat on a rooftop or other surface, or sometimes attached to motorized structures that keep the cells pointed toward the sun as it crosses the sky.

Now, a team of MIT researchers has come up with a very different approach: building 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 MIT team initially used a computer algorithm to explore an enormous variety of possible configurations, and developed analytic software that can test any given configuration under a whole range of latitudes, seasons and weather. Then, to confirm their model’s predictions, they built and tested three different arrangements of solar cells on the roof of an MIT laboratory building for several weeks.





Although computer modeling by Grossman and his colleagues showed that the biggest advantage would come from complex shapes — such as a cube where each face is dimpled inward — these would be difficult to manufacture, says co-author Nicola Ferralis, a research scientist in DMSE. The algorithms can also be used to optimize and simplify shapes with little loss of energy. It turns out the difference in power output between such optimized shapes and a simpler cube is only about 10 to 15 percent — a difference that is dwarfed by the greatly improved performance of 3-D shapes in general, he says. The team analyzed both simpler cubic and more complex accordion-like shapes in their rooftop experimental tests.

At first, the researchers were distressed when almost two weeks went by without a clear, sunny day for their tests. But then, looking at the data, they realized they had learned important lessons from the cloudy days, which showed a huge improvement in power output over conventional flat panels.

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.


A few other efforts — including even a middle-school science-fair project last year — have attempted 3-D arrangements of solar cells. But, Grossman says, “our study is different in nature, since it is the first to approach the problem with a systematic and predictive analysis.”

David Gracias, an associate professor of chemical and biomolecular engineering at Johns Hopkins University who was not involved in this research, says that Grossman and his team “have demonstrated theoretical and proof-of-concept evidence that 3-D photovoltaic elements could provide significant benefits in terms of capturing light at different angles. The challenge, however, is to mass produce these elements in a cost-effective manner.”

markaivaz  - Idea to help the 3-d or accordion solar panels 2012-03-28 11:54:31
With the problem of shadows; why not use mirrors at the base of the towers. These could be oriented to reflect the sun's rays to the panels that are not directly facing the sun. It may make the "footprint" a little larger at the base but the mirrors could also be used in an accordion fashion, and or, at the bottom.
ushomebuilders  - test site 2012-03-29 04:19:09
Wonderful work. As a green builder of custom homes, we love to see innovation. If you ever need a test facility on a real home, give us a call. Oregon weather just off the coast would be a great test. We have solar tech installers and would love to help in testing.


Anthony Moore
hammenu  - Canadian Renovation Contractor 2012-03-29 06:55:41
I own and operate a small company that does medium to large renovations. Part of our model is to perpetuate an environment that fosters a better, cleaner, greener way of construction.

Currently we are looking at shifting our focus to heat pumps and solar energy. We would also be interested in beta testing for you. We can provide comprehensive reporting on our finding. We can scale where we are at and the impact that follows, be it positive or negative.

Keep up the good work. We have foreseen this type of change in technology and have held back, waiting for something more efficient to come onto the market. This looks like that something!

Rick Kelly
Forge Construction
Shailendra  - add sun tracking 2012-03-30 04:03:51
Sir, will the output increase if the panels arranged in 3D are following sun direction (single axis tracking)?

pbreithaupt  - Do you need MPPT technologies? 2012-04-02 08:50:00
One vital question remains: Due to the constant changing shades it's very likely that standard inverters (single power point) are not fit for these structures. How much power do we lose by applying Maximum Power Point Tracking (MPPT) technologies?
AlGina  - Size 2012-09-19 06:12:27
What was the size of the orginal test tower?
What was the cost to build?
I want one.
AlGina  - Size 2012-10-29 05:50:02
What was the size of the original test tower?
What was the cost to build?
I want one.
Can you put a magnifying dome over the unit?
Can you make it to attach to PowerSource 1800 (
What would be the cost to modify?