Published on September 14th, 2012 | by Glenn Meyers1
What We Night Reap from Biohybrids
David Thomas has provided this article on the subject of biohybrids, an alternative way of generating electrical energy from the sun using plants.
Thomas could not send the article as quickly as desired, as he was waiting for another scientist to interview. The call never came and Thomas finally wrote, “I’m tired of waiting for this scientist to get back to me. I don’t think the article needs him anyway. Here is the article on biohybrids. I quite like it.” So do I!
The renewables industry has its own arms race going on. The goal here is to produce clean energy, and the inspiration is nature herself.
Photovoltaics (PV) is one of the biggest renewable industries. Plants have been processing energy from sunlight for much longer than we have, and they so far have been doing so much more efficiently too. The renewable heat and wind industries have no direct natural precedents but when it comes to solar the plant kingdom has us in the shade.
H E L I O T R O P I S M
Plants such as sunflowers tilt their stems to follow the path of the sun through the sky, meaning they drink in the maximum amount of sunlight. That’s why they’re called sunflowers.
Some commercial solar installations already use GPS technology and motorised frames to adjust their tilt throughout the day, but there are flaws: this method is only moderately efficient, is not energy efficient as the motors eat up power, and the moving parts can break down. These flaws are also barriers to heliotropic panels breaking into residential systems as it overcomplicates the technology.
At the chemical level plants move their petals by transferring potassium – somewhere between hydraulics and magnetism. Professor Hongrui Jiang at the University of Wisconsin-Madison has been using carbon nanotubes and liquid crystalline elastomer, which contracts under heat, so it can be driven directly by sunlight. Professor Jiang explains, “The idea is that wherever the sun goes, it will follow”.
His experiments will hopefully introduce heliotropism to solar panels without increasing the number of moving components or using electronics that require extra power. It’s thought Prof Jiang’s experiments could increase solar efficiency by 10 percent.
P H O T O S Y S T E M 1
Photosystem1 (PS1) is a plant protein used in photosynthesis. Vanderbilt University researchers David Cliffel and Kate Jennings have created a biohybrid solar cell, combining silicon and PS1 “that produces current levels almost 1,000 times higher than… various metals”. Their research has received global coverage because of their use of spinach to harvest the plant protein. PS1 features widely in PV research but Cliffel and Jennings are achieving some of the better results in their field.
Cliffel claims, “We could reach the range of mature solar conversion technologies in three years.”
Part of her winning award at the National Sustainable Design Expo will enable Jennings and the team to build a prototype that will bring this biohybrid technology one step closer to market.
S O L A R M U L C H
Andreas Mershin, a researcher at MIT’s Centre for Bits and Atoms has mixed a cocktail of chemicals that can be mixed with green organic matter: grass clippings, leaves, stems, or any other vegetation containing chlorophyll. The chemical cocktail first extracts the PS1 from the plant matter. This has been achieved by many scientists already, but Mershin claims he is the first to be able to preserve the PS1, which usually degrades fairly quickly without its life support machine – the plant itself.
Mershin’s chemical cocktail is potentially cheap to produce and would not be costly to buy. The mulch would then be used to coat an array of zinc oxide wires and titanium dioxide ‘sponges’ to produce a moderate amount of electrical energy. The mulch could be reproduced and sloshed back on whenever necessary.
Mershin says, “Leaves and plants are nature’s solar panels… If we manage to somehow hijack the molecules that are responsible for photosynthesis… this would represent a fantastic and disruptive new step in the way we generate solar power or electricity in general.”
A N E W D A W N
Solar hardware is evolving. I’m 26 years old, I write about renewable energy and I enjoy science fiction: I’m inclined to believe that in my lifetime I will see biohybrid design replacing many mechanised technologies. Others might think differently; we’ll see who is correct.
Author’s bio: “Hello, I’m David Thomas. I write about energy efficiency and about the solar industry for websites Greendeal.co.uk and TheEcoExperts.co.uk. I take an interest in new research and government policy. Talk to theecoexperts and either myself or a girl called Lima will respond.”
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