Climate Solutions from Solar Forests and Artificial Leaves

by Emily Gertz

categories: Clean Energy, Forests, Greenhouse Gas, Imagining the Future, Science, Solutions

Published July 28, 2009 @ 10:45AM PT

Biomimicry is a rich source of inspiration for designers, engineers and scientists. They look at how evolutionary biology has solved problems, and then use artificial materials to recreate these solutions found in nature.

Many clean energy and climate solutions are turning to trees and other plants for design cues:

The Solar Forest concept, reported at Inhabitat, is racing around the blogs this week. It's designer Neville Mars' idea for an electric vehicle (EV) charging port powered by gracefully branching trees covered in solar panel "leaves." The leaves track the sun to generate power with maximum efficiency. Certainly the concept has a lot more aesthetic and pragmatic appeal than leaving acres of parking lots to bake in the sun.

Google, meanwhile, installed a "grove" of pole-mounted solar panels in the parking lot of its Mountain View, Calif. headquarters in 2006. It's the solar forest concept taken live, although lacking the sylvan look and feel.

And then there's "solar ivy" -- a concept product by a Brooklyn design group called SMIT (Sustainably Minded Interactive Technology) that seems to be on its way to market. Composed of netting covered in "leaves" made of flexible solar cells, the "Grow" system can be draped down the side of a building. In addition to converting light to energy, each solar leaf has piezoelectric generators on the underside as well -- so that as they flutter in the wind, that movement is harvested as energy as well.

"Artificial forests at nano scale" are another compelling avenue of research and development. The idea here is to create materials that mimic the leaf's ability to convert sunlight into energy, and then capture that energy for human uses. Another grail of this research is to find a synthetic way to emulate a leaf's ability to capture carbon out of the atmosphere and store it -- technology that could help us in re-stabilizing the climate.

The big news so far this year in artificial forests at nano scale is that a team of European researchers recently announced that they've succeeded in modifying chlorophyll from an alga so that it resembled the light antennae of bacteria, nature's most efficient photosynthesizers.

They then figured out the structure of these light antennae -- opening the way to creating an artificial leaf.

This isn't the first time there's been a wave of excitement on the synthetic photosynthesis front. In March of this year, researchers at the Energy Department's Lawrence Berkeley National Laboratory announced that nano-sized crystals of cobalt oxide can split water molecules into hydrogen and oxygen, the central part of the photosynthesis process.

In 2002, at the height of the "nanotech bubble," a team of scientists published research on using cadmium-laden nanocrystals to fix carbon dioxide (that is, transform it into other organic molecules, which is how plants store carbon absorbed from the atmosphere).

(And these are just two examples of what I'm sure are tens or dozens more.)

Why at the nano scale? In part because of the promise nano materials hold: when substances are created at these incredibly small scales, they often have properties that they don't exhibit at larger scales. For instance, they can have much more net surface area (to soak up sun) than the same materials at conventional macro scales.

Another reason is that nano-scale materials could potentially be incorporated into many relatively cheap substances we already use to cover big areas outdoors, like asphalt, concrete, rubber, paint, and vinyl. Imagine millions of homes sheathed in siding that incorporates nano-scale solar collectors, sitting in the sun all day and converting light into electricity.

So while nano materials research and development are often slow and expensive, the return on the time and money invested could be enormous in three ways: energy generated, carbon sequestered out of the atmosphere, and dollars earned.