|A new type of organic solar panel may soon make cars with tinted windows
and thumping stereos a shade greener. The technology is under
development by German startup Heliatek and aims to 'be instrumental in
establishing environmentally friendly solar energy as a widespread,
commonplace technology available to everyone.' To do this, they are
rolling out solar panels that are made via a vacuum deposition process
that puts small organic molecules on flexible films.
Organic solar cells have been around for decades. The idea behind them
is that certain organic molecules-typically types of long polymers-could
be cheaply printed, leading to very-low-cost solar cells. But such cells
have proven inefficient and have had relatively short lifetimes, so they
are used only in niche applications.
Heliatek's panels are more efficient than the polymer-based ones, and
are expected to last as long as a conventional silicon solar cell. The
company uses short molecules called oligomers instead of polymers.
Oligomers are inherently more stable, and can be deposited using a
vacuum-deposition process that allows for precise control over the
thickness and uniformity of the resulting films.
The organic solar panels convert about 8% of the energy in light into
electricity whereas conventional solar panels are in the 14 to 15%
efficiency range. But, in cloudy weather or hot environments, which make
conventional panels less efficient, the organic ones hold their own.