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The future of solar is looking much brighter

Solar power is taking off around the world.  Europe is planning to deploy various types of solar power to the Sahara to provide for the European Union's energy needs.  Meanwhile, here in the U.S., California is expanding its solar efforts as well.

However, amid the progressing adoption of solar technology, one perpetual criticism that persists is that solar power is inefficient and expensive.  To some extents this is true.  The current generation of photovoltaic solar panels -- the type of solar power perhaps most associated with the field -- is only around 20 percent efficient and thus costs remain relatively high, like many forms of alternative energy.

A new breakthrough from U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is looking to solve those problems.  It pushes solar cells to uncharted technology with a record 40.8 percent efficiency.  The new work shatters all previous records for photovoltaic device efficiencies.

The researchers first used a special type of cell, an inverted metamorphic triple-junction solar cell.  The custom cell was designed, fabricated, and independently measured at NREL.  The next step was to expose the solar cell to concentrated light of 326 suns, yielding the record-breaking efficiency.  A sun is a common measure in the solar power industry which represents the amount of light that hits the Earth on average.

The new cell targets a variety of markets.  One potential market is the satellite solar panel business.  Satellites natural absorb more intense sunlight, thanks to no atmospheric interference.  Another possible application is deployment in commercial concentrated PV cells.  Concentrated PV is a burgeoning field, with several companies currently contracted worldwide to build the first utility grade plants.

The new record was welcome news, but little surprise at NREL -- they held the previous record as well.  In order to beat their old design, one key was to replace the germanium wafer at the bottom junction with a composite of gallium indium phosphide and gallium indium arsenide.  The mixture splits the spectrum into three parts, each of which gets absorbed by one of the junctions.  Both the middle and bottom junction become metamorphic in the new design.  This means their crystal lattices are misaligned, trapping light in the junction and absorbing more of it.  This yields an optimal efficiency.

One key advantage is the new solar cell can be conveniently processed by growth on a gallium arsenide wafer.  It is also both thin and light.  The NREL believes this cell will be cheaper than current commercial models, while delivering far more power.

Some of the credit for the work goes to NREL's Mark Wanlass, who invented the cell's predecessor.  The new cell was redesigned by a team led by John Geisz.

The NREL is operated by the DOE by Midwest Research Institute and Battelle.



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RE: No big deal
By nah on 8/18/2008 10:31:17 AM , Rating: 5
quote:
There are far more things involved with automobiles than purely fuel economy. Interior comforts/luxuries, storage space, towing capacity, safety features, etc. To make the insinuation that today's Toyota Camry is only marginally better than a 1908 Model T is asinine.


That may be correct--but you haven't looked at the other side of the equation--what was the price of a Model T in 1908--around USD 850, which, when adjusted for inflation is around USD 18,000 today--not much lesser than a Camry, while offering much fewer benefits. In contrast, the price of a solar cell has fallen by almost a hundred times (10.000 % ) over the last fifty years--while improving (in average efficiency) over 400%. Comparing between industries is moot--has the healthcare industry improved as dramatically as the IT one ? As someone said, if cars advanced as fast as processors a Rolls Royce would cost about USD 15, be more powerful than a train, could go around the world 2500 times on a tankful of petrol,and be so small that 6 could be parked on this full stop. Needles to say--it's only passengers would be microbes, or high ranking bacteria ;)


RE: No big deal
By ebakke on 8/18/2008 12:40:36 PM , Rating: 3
Sure, but you're comparing the first mass produced automobile to the first produced solar cells.

quote:
Comparing between industries is moot

I agree wholeheartedly that cross-industry comparisons provide little benefit. In fact, that was my whole point.


"And boy have we patented it!" -- Steve Jobs, Macworld 2007














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