Thursday, November 20, 2008

Maxmum Energy Cells

These two items give us a flavor of the gold rush now underway in the solar energy business. Both are still in the lab, but the promise of a rapid improvement of the underling technology is very clear.

The current rush to get mass production in full swing is not premature but a decision to grab market share while it is possible. With market share, the manufacturer is able to continually upgrade the installed base, particularly since we are already staring at a dollar per watt.

The lab work described below is promising that this cost will drop even to pennies per watt. That makes it easy to go back to an installation and cheaply replace the active cells with cells producing several times more power. You will only get to do that if you own market share like the telephone companies of old.

I have to believe that appropriate end products are already exiting the design stage. We will surely be seeing inexpensive solar products within months.

The best advice is to investigate the product on display for its capacity to upgrade. After all, the solar energy component will need to be replaced, while frames and electronics, costing as much or more will not. The majors will be quite aware of this and will surely be able to design in an accommodation.

New Solar Energy Material Overcomes All Obstacles to Produce Maximum Energy

Researchers have created a new material that overcomes two of the major obstacles to solar power: it absorbs all the energy contained in sunlight, and generates electrons in a way that makes them easier to capture.

Ohio State University chemists and their colleagues combined electrically conductive plastic with metals including molybdenum and titanium to create the hybrid material.

"There are other such hybrids out there, but the advantage of our material is that we can cover the entire range of the solar spectrum," explained Malcolm Chisholm, Distinguished University Professor and Chair of the Department of Chemistry at Ohio State.

The study appears in the current issue of the Proceedings of the National Academy of Sciences (PNAS).
Sunlight contains the entire spectrum of colors that can be seen with the naked eye -- all the colors of the rainbow. What our eyes interpret as color are really different energy levels, or frequencies of light. Today's solar cell materials can only capture a small range of frequencies, so they can only capture a small fraction of the energy contained in sunlight.

This new material is the first that can absorb all the energy contained in visible light at once.

The material generates electricity just like other solar cell materials do: light energizes the atoms of the material, and some of the electrons in those atoms are knocked loose.

Ideally, the electrons flow out of the device as electrical current, but this is where most solar cells run into trouble. The electrons only stay loose for a tiny fraction of a second before they sink back into the atoms from which they came. The electrons must be captured during the short time they are free, and this task, called charge separation, is difficult.

Solar PV manufacturer
Oerlikon Solar has pioneered a new thin film solar technology process, which it claims has made its solar cells 7 per cent efficient - a 16 per cent energy improvement over its previous technology. The advance has led to a 50 per cent increase in the capacity of its thin film solar fabrication plant.

So, why is this important? Well, thin film cells are typically a lot cheaper to produce than more common silicon solar cells, but often suffer from significantly lower conversion efficiencies. Oerlikon’s breakthrough moves us a lot closer to the day when thin film becomes more cost-effective than silicon-based panels - which could mean a dramatic rise in the adoption of solar power in homes and businesses.

As Chris O’Brien, head of Market Development at Oerlikon explains, “We see a clear path to improve the performance of this technology to deliver the capability to produce PV modules at significantly under $1.00/W within the next two years.”

The new process, called Amorph High Performance, optimises the use of Zinc Oxide (ZnO) material, which has superior light-trapping properties. The technique means that amorphous silicon can be deposited over a much larger area than is possible when crystalline silicon is sliced to form ‘wafers.’

The breakthrough marks an important step in the race towards the mass adoption of solar technology, and is likely to be closely watched by competitors such as NanoSolar, First Solar and Miasole.

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