Doctoral Student Yimu Zhao and Prof. Richard
Lunt examine new transparent solar cell.
Photo by G.L. Kohuth.
Will Alexander of
Motherboard brings us the fun news of an improvement in thin film solar panels that makes them transparent in the visible part of the EMF spectrum, but able to convert photons to electrons in parts of the rest of the light spectrum. In,
With Transparent Solar Panels, Windows Could Harvest Energy Too, Alexander notes that while these new transparent thin-film solar collectors are only 1% efficient, researchers hope they can achieve 5% efficiency. Current solar PVC typically range from 15% to 25% with some new technologies, yet to be offered economically in high production even higher.
But under the "smoke em if you got em" philosophy researcher asks 'why not pick up every bit of energy we can, from every surface available in large urban areas?'
Researchers from Michigan State University report that they've developed transparent, luminescent concentrators that can be placed on windows, your phone screen—anything with a clear surface—without blocking the view. ... “We can tune these materials to pick up just the ultraviolet and the near infrared wavelengths that then 'glow' at another wavelength in the infrared,” Lunt explained in a statement. “Because the materials do not absorb or emit light in the visible spectrum, they look exceptionally transparent to the human eye.”
The infrared light is trapped and guided to the edges of the plastic solar concentrator, where photovoltaic cells convert it into electricity. That's one of the reasons solar luminescent concentrators (LSCs) are attractive alternatives to more conventional photovoltaics: They can harvest light from a larger area without having to track the Sun. The materials are also comparatively inexpensive, which could potentially make for cheaper solar power.
The idea is like that of cheap, printable plastic solar panels, but its the transparency that makes it particularly attractive. This type of research has been conducted before in see-through films, but previous work used coloured materials and produced little energy. "No one wants to sit behind coloured glass," wrote Lunt. "We take an approach where we actually make the luminescent active layer itself transparent."
Coming back to Will Alexander's question of why not collect every photon available ffor conversion to electricity? Well, the issue would be return on investment. Perhaps we should be using every available surface area to capture solar energy. However, from the perspective of a strategy for converting our entire world to renewable energy and eliminating coal fired, and eventually all fossil fuel burning power plants A.S.A.P. shouldn't we go after the long-hanging fruit first?
Why not put up 20% efficient regular solar collectors on all the non-window parts of skyscrapers first? And, because of shadows, we should probably use up deserts and cheap land near for existing solar panels which are now nearing or already crossing grid parity in some areas.
In many southt-western desert states, in the U.S., vast unused areas near power hungry cities could be used with currently proven, cost-economical regular solar modules to generate large amount of electricity which will likely be more cost-effective than 1% collectors even taking into account the cost of improving transmission lines.
Please do not get me wrong, I'm excited about new technology and inventions, I'm posting this here. My only points are as advocate for renewable energy we have to keep our wits sharp and learn how to evaluate the hard core practical large-scale generation options from the really exciting new headlines of what may be a major contributor in the future.
Even now we can probably find immediate applications where available surface area is the constraining factor, rather than cost of efficiency. For example perhaps on space vehicles where every millimeter of possible energy capture space will want to be tapped. Alexander offer examples of keeping cell phones or e-readers charged, and using car windows.
Also, it's valuable for us to know about every possible option, and the way ttot analyze their pros and cons so we learn more about the science, economics behind the numerous dimension of converting our world to renewable, clean energy generation and eliminate fossil fuels.
Also please check out mimi's post Join the People's Climate March in NYC - All About CARBON - which is part of our blogging marathon to promote the People's Climiate March in NYC, at 11:30 am, Sunday, September 21st.