13/05/2013
Transparent solar panels — think
about it for a moment: Sheets of
transparent glass or plastic film that
also generate electricity. It’s almost
the perfect solution for all our energy
needs, generating free power from
every available surface, window, and
computer display.
The concept of transparent solar
panels isn’t new, of course, but it now
looks like they’re finally finding their
way to market: Ubiquitous Energy, a
startup that was spun off from MIT
last year, is developing a technology
and patent portfolio and hopes to bring
affordable transparent solar panels to
market soon.
At this point, you might be wondering
how transparent solar cells actually
work — after all, if it’s transparent,
how can it absorb light energy? The
simple answer is that light energy
comes in many frequencies (colors),
but as far as we humans are
concerned, it is only the visible
wavelengths — from blue, through
green and yellow, to red — that really
matter. The Sun, however, pumps out
a huge amount of infrared light, and
some ultraviolet light — both of which
are invisible to the human eye, but
which can also generate large
amounts of electricity if captured by a
solar cell.
The trick, then, is creating a solar cell
that only absorbs IR and UV radiation,
while letting visible light pass straight
through. According to Technology
Review, Ubiquitous Energy’s
transparent solar cell is built up from a
series of organic layers on glass or a
flexible film. We don’t know the exact
nature of the organic materials being
used, but other organic solar cells
generally use organic polymers that
might’ve had their molecular makeup
altered to absorb specific wavelengths
of light. There are other ways of
building transparent solar cells,
though: As we reported last year,
researchers at UCLA and UC Santa
Barbara made a flexible, high-
efficiency cell from a mesh of
transparent, photovoltaic silver
nanowires.
