Solar power is good enough for the biosphere, so by golly it’s about time it was good enough for human industry! Of course, photosynthesis is only 6% efficient. That number includes the biological losses, the absorption ratio (if I understand the numbers from that link correctly) is 34%. According to various sources the absorption efficiency of solar panels seems to max out around 40%, with power conversion efficiency of 6%, so state of the art is roughly comparable to nature (though of course, manufacturing cost is another matter). However, a new nanomaterial-based coating seems to have been developed that boosts absorption by ~40%:
The new RPI solar cell is a normal cell covered in a special anti-reflective coating which traps sunlight from nearly every angle and part of the spectrum. The new cell is near perfect; it absorbs 96.21 percent of the sunlight shined on it, while a normal cell could only absorb 67.4 percent. That 43 percent efficiency boost, coupled with mass production, if properly implemented could place solar on the verge of competing unsubsidized with coal power, at last.
Shawn-Yu Lin, professor of physics at Rensselaer and a member of the universityâ€™s Future Chips Constellation describes the breakthrough, stating, “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 sunâ€™s position in the sky. Our new antireflective coating makes this possible.”
This is pretty exciting, especially if the mass production can work out. Even if power conversion efficiency stays the same, improving absorption by 40% should boost the total power output by the same amount.