Amorphous silicon solar panel

Cheap solar panels made from amorphous silicon (instead of the more expensive, yet more commonly used crystalline silicon) will now be more efficient.

Researchers at TU Delft have discovered a way to increase the efficiency of these less-expensive solar panels from 7% to 9%.  Even though its very cost-effective to produce amorphous solar panels with thin film solar technology, the conversion of sunlight energy into electricity has always been much lower than crystalline solar panels (18%).

By boosting the efficiency of the so-called amorphous silicon panels, consumers will not have to sacrifice as much efficiency for lower cost solar power.

To read more about the research and discoveries made by Researcher Gijs van Elzakker, check out the full story at ScienceDaily.

A silicon solar panel up close

It is such a basic idea, it is surprising that someone didn’t point this out earlier.  The gorgeous, deep-blue PV panels that gleam in the sunlight can be a lot more efficient if they were a less reflective.  Of course!  Just think that when the light bouncing off solar panels is absorbed instead, dull solar panels can generate more electricity.

Silicon is the primary ingredient of most solar panels manufactured.  However, bare silicon cells only absorb two-thirds of sunlight energy.  When glass is added to the top for protection, reflection increases and efficiency goes down.  As explained in NewScientist:

“To address that, anti-reflective coatings are added to the silicon of commercial solar cells, but they still allow much light to be reflected. Most cells use a coating that is designed to force reflecting photons to get tangled up with new photons striking the cell.”

Earlier this month, scientists unveiled a new solar cell with record-breaking efficiency.  Have you guessed it yet?  Yep – it was a dull solar panel.  Credit goes to Martin Green, at the University of South Wales, Australia, who led the research team to the new world record.

The technical operation is explained:

“An anti-reflective surface cuts reflection to 3% across most of both the visible and infrared spectrums, helping them to convert 25% of light energy into electricity.”

Even if you are not a scientist, it is easy to understand that 25% efficiency is superb when it comes to solar panels.  Talk about turning something dull into a bright idea!

Dull solar panels are created in part by using an anti-reflective coat comprised of silica and titanium dioxide.  Seven layers of this coat work together to “smooth out” the entry of light into the solar cell, minimizing reflectance.  Each layer contains more titanium dioxide than the previous one, in effect drawing the photons in, instead of allowing them to bounce out.

The 7-layer coating was developed by a team led by Shawn-Yu Lin at the Rensselaer Polytechnic Institute in Troy, New York.

Are you as impressed as I am?  Well, you may be wondering about the cost of dull solar panels, compared to ordinary PV panels.  The seven-layer coating only adds 4% to the total cost of the panels, but it cuts the reflection across the light spectrum to an impressive 4%.  The trade-off is gained in the greater efficiency and much lower reflectivity.

What about the protective glass cover for the panels?   Scientists are also tackling that issue, inspired in part by the eyes of a moth.  Moths’ eyes have evolved to not waste any available light, so why not create glass taking cues from nature?  The following description of non-reflective glass explains the advanced design:

“The design consists of densely-packed, 500-nanometre-tall spikes, tapering from a point at the top to wide at the bottom.”

The effect is much like the 7-layer dull solar panel coating.  And the results are equally impressive: reflection is cut down to only 5% across the light spectrums.

Kudos go to the stellar researchers, Peng Jiang and Chih-Hung Sun at the University of Florida, and Bin Jiang at Portland State University for their advanced research on non-reflective solar panel glass coatings.  These brilliant minds plan to establish a start-up company to manufacture and sell more efficient solar panels.

From everything I have read, dull solar panels seem to be the next big thing in solar energy!  Could it be that within the next 5-10 years, the shiny PV panels we now see on buildings will be a thing of the past?  What do you think about the bright ideas of these brilliant scientists?  Personally, it sure makes me wish I paid closer attention to my high school chemistry teacher.