Solar panels have come a long way since the first models were unveiled in Japan some 40 years ago. They are much more efficient than their predecessors, and most importantly for the UK, they no longer require direct and strong sunlight to operate.

But there’s still room for improvement, especially in two key areas. Current panels on the market absorb about two thirds of the sunlight that hits them whilst the other third reflects and bounces off – sunlight that could be used. They are also very dependent on being at exactly the right angle to get the most sunlight, which can restrict a lot of buildings facing the wrong way.
 
Researchers at the Rensselaer Polytechnic Institute (RPI) in New York have made significant progress recently in these areas. They have developed a new antireflective coating for solar panels that captures over 95% of the light that hits it, and expands the spectrum of light available at almost all angles. This means panels can remain stationary and generate their full capacity all day long.

Professor Shawn-Yu Lin, who headed up the year long project seems pretty pleased with his achievement and thinks the discovery could hold the key to more wide scale, cost effective solar generation.

He uses a nice analogy about layers of trees in a forest sucking in the light and not letting it out to explain the obvious: nanoengineered titanium dioxide nanorods at oblique angles attached to a silicon substrate via chemical vapor disposition!

“Typical antireflective coatings are engineered to transmit light of one particular wavelength. Lin’s new coating stacks seven of these layers, one on top of the other, in such a way that each layer enhances the antireflective properties of the layer below it. These additional layers also help to “bend” the flow of sunlight to an angle that augments the coating’s antireflective properties. This means that each layer not only transmits sunlight, it also helps to capture any light that may have otherwise been reflected off of the layers below it."

If solar panels can generate more energy more of the time, the financial argument for buying them will become stronger. Commercially, the farms won’t need to rotate the panels to follow the sun, and at home, fixed panels to the roof will power a lot more. Although he hasn’t said much about how much this process adds to the cost of the panel. Hmmm.

Anyway, good work Lin, at least we now know that panels can generate near 100% efficiency. 

Green Energy Republic