Advances in solar cell technology

July 1, 2008

New technologies in solar are moving so fast it’s hard to keep on top of it.
It’s becoming abundantly clear that solar cell production is not moving fast enough, and companies are scrabbling for alternatives to silicon that are more affordable, can be produced more rapidly and with less toxic waste associated with some of the production methods.

Production of silicon solar cells used up to 33% of the world’s electronic grade silicon production in 2006. In addition, the production of silicon is expensive and some production methods entail hazardous chemical solvents that can find their way into the environment.

Video of solar panel production.

Toxic waste
One byproduct of polysilicon production is silicon tetrachloride, a colorless, toxic liquid that causes irritation to the respiratory tract, sneezing, coughing, burning throat, a constricting sensation of the larynx and difficulty in breathing. When it combines with water it becomes highly corrosive to metals.

A recent article in the Washington post exposed how solar cell production in China is leaving behind toxic waste, dumping it openly and polluting the land and aquifers.

There is interest in producing silicon from other materials, such as rice hulls, but even this requires leaching the silicon from the hulls with hydrochloric acid. http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6204723

With all this in mind, many are turning from silicon to find less expensive options. A recent testing of dye-sensitized, silicon-free solar cells in China holds promise.

The technology entails printing a thin film of nano-sized particles of titanium dioxide which is then sprayed with dye which is in contact with an electrolyte solution. When solar radiation hits the dye it injects a negative charge in the pigment nano-particle and a positive charge into the electrolyte solution, which converts sunlight into electrical energy.

So far, the thin film panels
are less efficient than silicon, but there are hopes that productivity can increase significantly soon and compete with silicon in a real way, thereby reducing the cost of solar energy to our environment.

Algae biofuel, are we getting closer?

May 30, 2008

It’s possible that the green slime we try to eradicate from our fish ponds could be the answer to our fuel problems. As it dawns on the world that biofuels made from food products are not really such a hot idea, scientists have quietly been studying algae as the next biofuel.

Not only does algae grow pretty much anywhere-from sewage sludge to fresh or salt water, it has a theoretical yield of several times that of corn with a lower processing cost. A 2004 study at University of New Hampshire concluded that all the transportation fuels in the United States could be supplied by algae grown on about 3% of the U.S. land devoted to farming crops and grazing for animals.

Pipe dream? Some say so. There has been a lot of hype over algae based biofuel, and a lot of money is being invested, but whether it’s a scalable alternative is yet to be proven. Arizona based GreenFuel is one of the leaders in the field. Their idea is to pump the CO2 emissions from coal plants into the GrenFuel bioreactors where the algae would eat the emissions as food. The algae is then processed and the biofuel extracted.

Aurora BioFuels in Alameda California is using genetically modified algae to create a high oil content and can create “bio-diesel with 125X higher yields and 50% lower costs than current production methods”.

But when genetic modification rears it’s ugly head -especially near the fragile San Francisco bay’s ecosystem- people may not be so enthused. Another start-up, Green Star, is enhancing production with nutrients, claiming they

If you’re interested in learning more as progress crawls forward, check out the Algae Biomass Summit
to be held in Seattle in October.

Slimy green gold? Algae biofuels

May 30, 2008

Affordable Solar? It’s done with Mirrors

May 22, 2008

DIY WAve Generated power

May 18, 2008

Is biofuel really an alternative?

May 12, 2008

Everybody seems to be surprised that the advent of biofuels as a gasoline alternative has had an impact on not only the environment, but on the world food supply.

David Lorenz and David Morris from the Institute for Local-Self Reliance published some findings in 1995, but apparently nobody was listening.

In 2007, WCCO TV in Minnesota ran this piece called “Will Ethanol Fuel a Food Shortage?” http://wcco.com/topstories/good.question.ethanol.2.367063.html

Oh, and if you’re thinking of rushing out to stat farming for biofuels, think again. Or at least read this study from Rutgers about how to calculate the cost of farming.
The high costs of farming, compared with the high risk factors involved still make it hard for a small farmer to make a profit.

In addition to increasing the cost of everyday foods, the rush to produce more corn could impact even the oceans in a major way. The Dead Zone is a huge area of water - over 7,000 square miles – that forms every year as a result of nitrogen leaching from fertilized corn fields in the Midwest into the Mississippi river system. The nitrogen causes a huge algae bloom which then suffocates aquatic life in the area.

So bottom line. If we reach the expected production level of 15 Billion gallons of ethanol and we use over 285 Billion Gallons of gas/year, is the drop in the bucket worth it? Or should we be looking for some other options?

Bicycle Generator for your laptop

May 8, 2008

When is Apple going to come out with one of these eh?