Sunday, April 20, 2008

Green PVs


Here is an oldie from the second year of EFA.
Natural Solar

If humankind is going to meet the challenges that lay ahead, we will do well to copy nature not only in its intricate complexity but also in its graceful simplicity.

Here is a very encouraging development for photon to electron devices:

Synthetic Molecules Capture Solar Energy
Green Building Press
September 5, 2006

A leaf is a highly efficient solar cell and researchers in Sydney have created molecules that mimic those in plants. Like the cells in plants, they harvest light and create power. According to the research team, led by Dr Deanna D'Alessandro, the best leaves can harvest 30 to 40 per cent of the light falling on them. The latest state of the art solar cells are only 15 to 20 per cent efficient, and expensive to make. But the researchers say they have recreated some of the key systems that plants use in photosynthesis.

Bacteria and green plants use photosynthesis to convert light energy into usable chemical energy. Wheel-shaped arrays of molecules called porphyrins, collect light and transfer it to the hub where chemical reactions use the light energy to convert carbon dioxide into energy-rich sugar and oxygen.

This process, which occurs in about 40 trillionths of a second, is fundamental to photosynthesis and is at the base of the food chain for almost all life on Earth.

More than 100 of the newly constructed synthetic porphyrins can be assembled around a tree-like core called a dendrimer to mimic the wheel-shaped arrangement in natural photosynthetic systems. The molecules designed by the team are about one trillionth the size of a soccer ball.

But the large number of porphyrins in a single molecule means that a significant amount of light can be captured and converted to electrical energy – just like in nature. Since they are so efficient at storing energy, D'Alessandro believes they could also be used as batteries – replacing the metal-based batteries that high technology devices depend on.

The team say their preliminary results are very promising, although they are still in the early stages of building practical solar energy devices using the molecules.

Now they’ve made the molecules, the team along with their Japanese collaborators at Osaka University are working to combine them in the equivalent of a plant cell.

Over the next five years they will attempt to scale the technology up to commercial scale solar panels. "

And here is another announcement that may reduce the costs of present PV systems by reducing the cost of the silicon:

Dow Corning Introduces New Solar Grade Silicon Material
Clean Edge
September 4, 2006

MIDLAND, MI -- Dow Corning (Nachrichten) Corp. today announced that it has achieved a milestone in solar energy technology: a solar-grade (SoG) silicon derived from metallurgical silicon that exhibits good solar cell performance characteristics when blended with traditional polysilicon feedstock.

This new silicon feedstock material, Dow Corning(R) PV 1101 SoG Silicon, is the first commercially available feedstock produced from such technology using large scale manufacturing processes. For several years, the primary obstacle to the growth of solar energy has been the constrained availability of silicon, the key raw material used in the production of solar cells.

Until now, Dow Corning says, the solar industry has relied on the supply of polycrystalline silicon, a high-grade purity product, originally developed for the semiconductor industry. This has meant that the solar industry has in turn been subject to resource restraint.

The launch of PV 1101, produced from a very different route, will alleviate that restraint and offer a new source of supply as well as new technical and business options for the solar industry.

"PV 1101 is certainly one of the most innovative technologies to come along in the solar energy industry since the manufacture of the first silicon solar cells," said Gaetan Borgers, director of Dow Corning Solar Solutions.

"For years now, the solar industry has hoped to be supplied by new sources of silicon designed and dedicated to them.

PV 1101 is a major step in that direction.

It is a step that will provide a means of growth for the solar industry."

We need inexpensive photon to electon strategies,

and advanced ultra caps to store it.

We need to accelerate the installation of advanced wind turbines,

We need smart, efficient homes and smart pedestrian oriented communities.

We need sporty motor in-wheel plug-in hybrids.

We need to act as if Climate Change and Peak Oil,

are coming to eat our children

and lay waste to our lives.

Cause they are.


HOME

What it is About

Earthfamily Principles

Earthfamilyalpha Content IV
Earthfamilyalpha Content III
Earthfamilyalpha Content II
Earthfamilyalpha Content

Links

LANGUAGE TRANSLATIONS

Labels:

0 Comments:

Post a Comment

<< Home