Researchers Extract Plant Material for Use in Solar-Energy Harvesting

1 saves
View Comments: Newest First|Oldest First|Threaded View
<<  <  Page 2/2
User Rank
Re: Natural fit
etmax   7/12/2013 11:33:41 AM
Thanks Karl, points well made but I think if you used the measure of how much of the solar radiation is a lattice match for Silicon (very narrow view) we would see higher numbers from silicon too up to 86% (although not as high as just the thylakoids). There's an IEEE article that suggests that quantum efficiencies of solar cells can exceed unity as sometimes two electrons are released for one photon. That's why I see narrowing the field of view to one thing only and not stating that is somewhat misleading. I'm not saying they are deliberately misleading us, more likely is a reporter left all of the stuff out he didn't understand resulting in the article.

User Rank
Re: Natural fit
karl   7/12/2013 11:08:16 AM
The efficiency discussed in the Wikipedia article is for the conversion of sunlight into biomass. The starting point, 100%, is for the conversion of the entire bandwidth of sunlight that falls on the leaf into biomass. The calculation of inefficiencies begins with subtracting all bandwidth that is not bioavailable, then all that is reflected from the surface of the leaf, and all photons that strike components other than cloroplasts. Energy used to make sugar, and energy used to keep the plant alive in the dark or to maintian roots are also deducted. This is therefore a measure only of what ends up as new growth, or biomass (while from the "plant's point of view" the goal is survival as a whole, and job well done!)

The scientists in the article are likely referring to the efficiency of the thylakoids, starting with 100% of bioavailable wavelengths that actually strike the cloroplast, and at only the conversion to electrons after splitting the water molecule. In fact, I think they are referring to the efficiency of the thylakoid for conversion of light to electrons.

There is one other inneficiency cited in the Wiki article that may affect the accuracy of the claim by the scientists:

"24% of the absorbed photon energy is lost due to degrading short wavelength photons to the 700 nm energy level"

If this loss is after absorption by the cloroplast but before the conversion by the thylakoids, then the scientists may be referring only to the efficiency of the thylakoids.

If the resulting solor cell technology they create uses the modified thylakoids to directly convert sunlight into electrons then the only loss when measured as other solar cells are measured would be the 47% of non-bioavailable soar bandwidth, leaving at least 50% for conversion. That's quite a good conversion, and double current technology.


User Rank
Re: Natural fit
etmax   7/12/2013 9:34:11 AM
Thanks for posting, it's interesting stuff. I was however puzzled at the claim of 100% efficiency in plants (or for photosynthesis, so I googled it and got this from Wikipedia: "which results in an overall photosynthetic efficiency of 3 to 6% of total solar radiation". Sugarcane is the exception achieving up to 8% This is a far cry from the 24% achieved in labs for silicon photocells. Wikipedia talks about the theoretical maximum being ~40% for the wavelengths that plants utilise but a lot of real world stuff gets in the way. This match more closely what I remember.

Here's the link for those interested:


I think maybe the boon here would be that they are sooo cheap that maybe acres could be covered for a few dollars (metaphorically)

User Rank
Re: Natural fit
vimalkumarp   7/12/2013 1:18:28 AM
This is Biomimetics at its best...!

Ann R. Thryft
User Rank
Re: Natural fit
Ann R. Thryft   7/11/2013 6:46:54 PM
This does seem intuitively obvious in a hindsight kind of way, doesn't it? Thanks for reporting these results.

Elizabeth M
User Rank
Natural fit
Elizabeth M   7/11/2013 7:07:00 AM
It makes perfect sense to use plants to harvest solar energy in solar panels or cells, as they're nature's original solar-energy harvesters. I am only surprised this type of research hasn't been going on longer. I think if there can be a way to use this method commercially, it could be a real breakthrough in solar energy cell development and certainly make the cells more environmentally friendly.

<<  <  Page 2/2
Partner Zone
More Blogs
It's been two years since the Mac Mini's last appearance on iFixit's teardown table, but a newly revised version joins Apple's lineup this week.
Science fiction author Isaac Asimov may have the best rules for effective brainstorming and creativity. His never-before-published essay, "On Creativity," recently made it to the Web pages of MIT Technology Review.
Much has been made over the potentially dangerous flammability of lithium-ion batteries after major companies like Boeing, Sony, and Tesla have grappled with well-publicized battery fires. Researchers at Stanford University may have come up with a solution to this problem with a smart sensor for lithium-ion batteries that provides a warning if the battery is about to overheat or catch fire.
In this new Design News feature, "How it Works," we’re starting off by examining the inner workings of the electronic cigarette. While e-cigarettes seemed like a gimmick just two or three years ago, they’re catching fire -- so to speak. Sales topped $1 billion last year and are set to hit $10 billion by 2017. Cigarette companies are fighting back by buying up e-cigarette manufacturers.
Advertised as the "Most Powerful Tablet Under $100," the Kindle Fire HD 6 was too tempting for the team at iFixit to pass up. Join us to find out if inexpensive means cheap, irreparable, or just down right economical. It's teardown time!
Design News Webinar Series
10/7/2014 8:00 a.m. California / 11:00 a.m. New York
9/25/2014 11:00 a.m. California / 2:00 p.m. New York
9/10/2014 11:00 a.m. California / 2:00 p.m. New York
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Oct 20 - 24, How to Design & Build an Embedded Web Server: An Embedded TCP/IP Tutorial
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6

Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: 10/28-10/30 11:00 AM
Sponsored by Stratasys
Next Class: 10/28-10/30 2:00 PM
Sponsored by Gates Corporation
Next Class: 11/11-11/13 2:00 PM
Sponsored by Littelfuse
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service