Plug Into a Plant: a New Approach To Clean Energy Harvesting

cylonlover writes "Millions of years have evolution has resulted in plants being the most efficient harvesters of solar energy on the planet. Much research is underway into ways to artificially mimic photosynthesis in devices like artificial leaves, but researchers at the University of Georgia are working on a different approach that gives new meaning to the term 'power plant.' Their technology harvests energy generated through photosynthesis before the plants can make use of it (abstract), allowing the energy to instead be used to run low-powered electrical devices."

Comments

Photo synthesis is not all that efficient.

[140Mandak262Jamuna]

From what I understand the efficiency of photosynthesis used by the plants is quite poor. Just about 2% or so. Even the chemistry used in photosynthesis has a theoretical maximum of 25%. Compare that to theoretical maximum efficiency of ideal Carnot engines at around 57% for typical gas engine source/sink temperatures and the 38%(? not very sure of this number, too lazy to look up) or so theoretical maximum efficiency for windmills.

Article is flat-out wrong.

[Geoffrey.landis]

This statement "Millions of years have evolution has resulted in plants being the most efficient harvesters of solar energy on the planet" is flat out incorrect.

Plants come in at about 2% energy conversion efficiency. The best solar cells are over 35% conversion efficiency.

Now, to be fair, plants aren't optimimized for energy conversion efficiency-- they are basically solar-powered engineering units that synthesize complex organic molecules and make self-replicating macromolecular structures out of little more than carbon dioxide and water, plus a few trace minerals... they are harvesting, mining, concentrating, and structural machines of amazing complexity. But "efficient energy conversion engines"-- no, not even close.

When the very first sentence of an article is factually incorrect, I have no interest in reading any more of it.

Re:Article is flat-out wrong.

[Anonymous Coward]

Nothing we can synthesize is as efficient on the nano-scale as Photosystems I and II

Typical solar cells now have an internal quantum efficiency well over 90% across the whole visible spectrum and slightly into near IR. Even when factoring in reflectance and issues with getting light into that region, the external quantum efficiency is over 80% from middle of blue into near IR. Photosynthesis on the other hand, has an internal quantum yield of about 10% in the red and blue regions, and dips to about 5% around the green region.