Minor Thoughts from me to you

Researches keep moving along with solar power advancements. The latest advancement is a new antireflective coating that allows solar panels to absorb more sunlight.

Researchers at Rensselaer Polytechnic Institute have discovered and demonstrated a new method for overcoming two major hurdles facing solar energy. By developing a new antireflective coating that boosts the amount of sunlight captured by solar panels and allows those panels to absorb the entire solar spectrum from nearly any angle, the research team has moved academia and industry closer to realizing high-efficiency, cost-effective solar power.

"To get maximum efficiency when converting solar power into electricity, you want a solar panel that can absorb nearly every single photon of light, regardless of the sun's position in the sky," said Shawn-Yu Lin, professor of physics at Rensselaer and a member of the university's Future Chips Constellation, who led the research project. "Our new antireflective coating makes this possible."

... An untreated silicon solar cell only absorbs 67.4 percent of sunlight shone upon it -- meaning that nearly one-third of that sunlight is reflected away and thus unharvestable. From an economic and efficiency perspective, this unharvested light is wasted potential and a major barrier hampering the proliferation and widespread adoption of solar power.

After a silicon surface was treated with Lin's new nanoengineered reflective coating, however, the material absorbed 96.21 percent of sunlight shone upon it -- meaning that only 3.79 percent of the sunlight was reflected and unharvested. This huge gain in absorption was consistent across the entire spectrum of sunlight, from UV to visible light and infrared, and moves solar power a significant step forward toward economic viability.

That's exciting stuff. Of course, there's a while to go yet before we have solar panels on our houses. The comments on the original article point out some of the remaining issues. For instance, this new coating requires 7 new layers on top of the solar cell. How expensive are these layers? Does the additional energy offset the additional manufacturing cost? What about converting that extra sunlight into electricity? The sunlight isn't necessarily converted into electricity just because it's absorbed by the panel. What about conversion efficiency? Existing panels convert sunlight to electricity at around 30% efficiency. New panels with this coating will collect more light but still convert it with ridiculously low efficiency.

To have a viable solar infrastructure we need panels that can absorb nearly 100% of the incoming sunlight, convert nearly 100% of the incoming sunlight, and convert the sunlight with much better efficiency. More than that, the final panels need to be relatively cheap or no one will be able to buy and use them. We're not there yet. But we are getting closer. And I look forward to the day that I can power a significant portion of my home's energy needs with solar energy.