For Breakthrough Energy It's a Nanoscale World

October 16, 2007 – Vol.12 No. 30

FOR BREAKTHROUGH ENERGY IT’S A NANOSCALE WORLD.

Promises, promises. Researchers for a few years now have been promising that nanotechnologies - materials created and processed at the molecular scale - will offer breakthroughs in energy related technologies. Solar and battery technologies are often mentioned.

Well, to some extent researchers and developers have been true to their word. State-of-the-art lithium ion batteries, for example, employ nanotech and sure enough those batteries are performing better than those without nanotech. For now the hopes and dreams for high-energy economy hybrid, plug-in hybrid and electric vehicles rest on those nanotech lithium batteries, so the technology had better deliver, or else.

Research into nanotech is one thing, but commercialization is another. (And of course more important.)

So here are two more nanoscale implementations, one commercialized, one holding a promise.

Braggone Ltd., of Oulu, Finland is now offering a process to apply a nanoscale spray coat onto silicon solar cells or the protective glass layer on them to minimize reflection as well as enhance the performance of the silicon itself.

The company says that silicon is very shiny and without any attempts to dull it a bit silicon can reflect up to 30 percent of incoming light. Typically some, but not all, solar cell companies apply a very thin antireflective coating to allow as much sunlight into the cell as possible.

Further, silicon must be very pure, or have few defects, to absorb significant amounts of sunlight. To improve on the quality of the silicon, hydrogen is employed in the manufacturing process, also known as hydrogenation

The standard method of applying a coating as well as hydrogenation is through another process called Chemical Vapor Deposition (CVD).

Braggone says that Chemical Vapor Deposition process is expensive and the equipment needs high levels of maintenance. It’s so costly, Braggone says, that some companies just don’t do it. By not employing CVD those company’s solar cells don’t have the power output they could have.

The company says its materials and the efficient spray, coat, bake and repeat process can replace the CVD process, at much lower cost. Low cost would mean any solar cell producer could use it and make the cells they already produce more efficient. Higher efficiency from the solar cells they already produce means that, effectively, those companies would be increasing their overall plant output capacity.

Braggone further says that companies that already use CVD can lower their production costs by switching to Braggone’s technique.

The innovative new product line is not only a breakthrough for crystalline silicon makers, but can also be used in thin film photovoltaics as well as in solar module manufacturing to further improve the power output of those products.

It appears as though Braggone has commercialized its nanoscale coating process and is ready to take orders.

On the research level here’s new material with nanoscale qualities: a plastic membrane that may provide a low energy method for the removal of salt from water, separate carbon dioxide from natural gas, or hydrogen from nitrogen.

The secret to the new plastic is in the hourglass shape of its pores. The hourglass shape allows molecules to separate faster and with less energy than other porous materials available today. The material, and those pores, mimic plant cell membranes which pass water molecules in and out of cells but block the passage of other molecules such as salt. In plants the hourglass cells are as known as aquaporins

In the man-made plastic material the pore size can be adjusted to block or pass different materials depending on the specific application - separating carbon dioxide from landfill gas extraction operations, or carbon dioxide from natural gas, for example.

The new plastic can separate carbon dioxide from natural gas a few hundred times faster than materials already in use. The purity of the remaining gases is four times that of current methods of separation, but not perfect. Occasionally an errant molecule can sneak through.

It is durable and can withstand high temperatures, qualities that are needed for many carbon capture applications. (Whether or not the plastic can be used to separate carbon dioxide from flue gases at powerplants is not mentioned by the researchers.)

The research into the plastic is a partnership between Hanyang University Korea, led by Professor Dr Young Moo Lee; the University of Texas, led by Professor Benny Freeman, and CSIRO (Commonwealth Scientific and Industrial Research Organisation), Australia's national science agency.

This plastic will help solve problems of small molecule separation such as separating greenhouse gases. Of course separating a greenhouse gas from others is only the first part of the equation. Doing something with it afterwards is another.

There’s still more research to be done. Maybe there’s a nanoscale solution to storing carbon dioxide permanently, and cheaply.

Links:

Braggone Ltd
http://www.braggone.com

CSIRO
http://www.csiro.au

The new material
http://www.csiro.au/news/FantasticPlastic.html