Unique alteration to standard flat-panel design
could be game changer for technology
Cubist enthusiasts rejoice! A novel concept by
researchers out of MIT might soon change the classic flat solar
panel to a three-dimensional cubic tower, as studies performed on
this new design reveal a significant increase in power output
Prototypes of the 3D solar panel towers
that MIT researchers developed.
While considerable research has been done in the
areas of improving performance and bringing down the cost of solar
photovoltaic systems, little attention has been paid to the ways in
which manufacturers could rearrange the cells to keep them pointed
toward the sun as it crosses the sky, thus increasing its power
At least that was
the case, until now.
MIT researchers built cubes and towers that
essentially extend the solar cells upward in three-dimensional
configurations. Doing this resulted in a power output increase
ranging from double to more than 20 times that of fixed flat panels
with the same base area.
These findings, which come from a combination of
both computer modeling and outdoor testing on prototype models, are
published in the journal, Energy and
The significance of these results is not lost on
at least one of the researchers. “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.
How they did it
The team, using a complex computer algorithm to
explore different configurations, discovered through a battery of
tests that the biggest increase came from models with complex
shapes. While some shapes proved to be more efficient than others
— a cube where each face is dimpled inward provides more
power output than a regular cube — they sometimes proved
to be too difficult/overly complex to manufacture.
The algorithm was adjusted to optimize and
simplify the shapes with as little loss of energy as possible. In
doing this, the research team discovered that they were able to
achieve about a 10-15% difference in power output between fully
optimized shapes and simpler cube designs. This much of a
difference, they felt, really doesn’t matter when you
look at the enormous difference that using 3D shapes in general has
on power output performance compared to standard flat panels.
From there, the team developed analytic software
to test the various configurations under a range of latitudes,
seasons, and weather. Upon confirming their model’s
predictions, they built and tested three different arrangements of
solar cells on the roof of an MIT lab building for several
The team was a bit dismayed at first when they
went almost two weeks without a clear, sunny day for testing. Their
feeling changed, however, when they looked at their data and
realized the huge improvements in power output on cloudy days
compared to flat panels.
Why does it work so much better?
The reason for the power output improvement
— and the uniformity of said output over time is that the
3D structure’s vertical surfaces have more area to
collect a greater amount of sunlight during mornings, evenings, and
winter, even when the sun is closer to the horizon.
The team thought about convenience, too, as can
be seen in the accordion- like tower design above. This was done so
that the technology could be shipped flat and unfolded on site.
This would be ideal for use in a parking lot to provide a charge to
electric vehicles, and on ventures to remote lands that lack any
sort of power grid.
Getting this idea off the ground
It should be noted that the cost of the 3D
module exceeds ordinary panels. It should also be noted that this
is balanced out by the much higher energy output that the 3D module
provides for a given footprint. And since the power output is more
predictable and uniform, integration with an existing power grid is
much easier than conventional systems.
Grossman feels that the time is now for an
innovation like this. “Even 10 years ago, this idea
wouldn’t have been economically justified because the
modules cost so much,” he says. But now, “the
cost for silicon cells is a fraction of the total cost, a trend
that will continue downward in the near future.” He adds,
“Currently, up to 65% of the cost of photovoltaic energy
is associated with installation, permission for use of land and
other components besides the cells themselves.”
While this idea has been approached before,
Grossman says, “. . . our study is different in nature,
since it is the first to approach the problem with a systematic and
The MIT team plans to next study a collection of
these 3D solar towers and account for the effect that shadows from
one tower cast on others can have on total power output at
different times of day. ■
MIT press release
Solar energy generationin three
dimensions article (for purchase)