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

The Potato Clock?

[jellomizer]

It sounds like a new approach to the Potato clock.

However I would like to point out the trade off. If you are going to produce energy with plants, (Sound green and all) but you will probably need to strip forests to give enough sunlight, as well as irrigation. For these plants that will not grow too much, because most of their energy is being taken away. You are better off growing switchgrass or other material to produce energy.

Re:So now we're stealing energy from plants?

[ArcadeMan]

The Matrix: Vegan Edition.

Not at all efficient

[cjameshuff]

Plants are nowhere near "the most efficient harvesters of solar energy on the planet". The most efficient plants, such as sugar cane, reach around 8%, on par with the very lowest efficiency photovoltaic modules. More typical efficiences are 0.1% to 2%.

English Laurel

[PPH]

I have an English laurel hedge. I'd plug into it except it has one of those big British style receptacles and I've lost my adapter.

Re:Photo synthesis is not all that efficient.

[140Mandak262Jamuna]

We clearly don't have all we need. I was just pointing to the fact "evolution has achieved the maximum efficiency" is a false statement. Usually they will play with the definition, and it is a warning sign. In this case they define "perfection" as the ability of the plants to emit an elector for each photon captured. But leaves and structures do not capture all the photons. They reflect most of it, not unlike solar cells. But in solar cell we define efficiency as the energy delivered to the wire to the solar energy incident on that surface.

OK, coming down further, plants do not use all the electrons, since they are trying to do an energy absorbing chemical reaction using that energy. Apples to solar cell comparisons show that photosynthesis is about 2% efficient in most plants, sugarcane reaches a peak of 7%.

But we can define cost efficiency to account for the cost of making it more efficient. If it is bio mass, that grows, replicates by itself and sustains itself, the cost of "manufacturing" the cell is practically zero. Cost of input energy is zero. Economically speaking bio mass, based on switch grass or algae must become cost efficient and competitive. It basically the interest on the cost of installation that determines economic viability of such projects. When other forms of renewable energy harvesting has such long history and hard data, this new fangled thing that has carbon nanotubes woven into leaf structure, is novel, interesting and might prove useful in a decade or two. But that is all that it is. A novelty. Nothing to get over excited about in the field of renewables.

The breakthrough we are all waiting for in renewables is not technical/scientific anymore. It is economic. Cheap natural gas is making coal too expensive. It is a good news bad news situation. Coal is not going to be economically viable soon. So powerplants grand fathered out of clean energy act which are steadfastly refusing to upgrade pollution control still burning coal all will switch to natural gas reducing pollution. But the bad news is, coal is replaced by even cheaper natural gas. The renewables must now beat even more cheap source of energy.

Re:Photo synthesis is not all that efficient.

[cjameshuff]

Except they're apparently harvesting the photosynthetic structures from plants and then incorporating them in something resembling a dye-sensitized solar cell using some exotic carbon nanotube substrate. That's not self-assembling, and given the lack of any cellular repair mechanisms, probably not very long-lasting.

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.