Nanoantennas, a new, more efficient method for solar power?

nanoantenna.jpgIdaho National Laboratory, Microcontinuum inc, and the University of Missouri have developed a new solar technology which can be imprinted directly on a flexible material. 

The process uses a special process to stamp microscopic square spirals called “nanoantennas” into the material each 1/25th the diameter of a human hair.  The nanoantennas are capable of collecting energy in the infrared spectrum so that even after the sun goes down they are still collecting power from heat being given off by the earth.

Commercial solar panels usually transform less that 20 percent of the usable energy that strikes them into electricity. Each cell is made of silicon and doped with exotic elements to boost its efficiency. “The supply of processed silicon is lagging, and they only get more expensive,” Novack says. He hopes solar nanoantennas will be a more efficient and sustainable alternative.

The team estimates individual nanoantennas can absorb close to 80 percent of the available energy. The circuits themselves can be made of a number of different conducting metals, and the nanoantennas can be printed on thin, flexible materials like polyethylene, a plastic that’s commonly used in bags and plastic wrap. In fact, the team first printed antennas on plastic bags used to deliver the Wall Street Journal, because they had just the right thickness.

By focusing on readily available materials and rapid manufacturing from inception, Novack says, the aim is to make nanoantenna arrays as cheap as inexpensive carpet

Unfortunately there are still a few setbacks.  The electricity generated by the nanoantenna is a very high frequency alternating current.  Alternating current is a type of electricity where the voltage alternates between a positive voltage and a negative one.  Ordinary house current does this around 60 times a second.  Unfortunately we are talking about a electricity that switches polarity ten thousand billion times a second, which we don’t really have a way of using at this point in time. 

The plan is to try and turn the alternating current into direct current so that it can be stored in a batteries and then later converted to a more usable alternating current as needed.  Many options are being explored on how to address this issue; the most probable being high speed rectifier diodes that would sit at the center of each antenna and convert the alternating current into direct current.  Diodes are semi-conductor components that block current flowing in one direction and allow it in the opposite direction.  By using these diodes the positive cycle of the current can be channeled to the positive side of the battery and the negative to the negative.  The result is a close enough approximation of direct current to be stored in a battery for later use. 

It will interesting to see how this develops over the next few years.  Solar collectors this cheap could result in nearly every building having a solar roof. 

futurist June 21, 2010 at 5:39 am

oh I hope so much this will develop into real-world thing!!!

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