Friday, August 20, 2010


Posted by Kudus

Hydrogen is one of two natural elements that combine to make water. Hydrogen is not an energy source, but an energy carrier because it takes a great deal of energy to extract it from water. It is useful as a compact energy source in fuel cells and batteries. Many companies are working hard to develop technologies that can efficiently exploit the potential of hydrogen energy.

With each passing day, scientists are coming out with unique solutions to lessen our dependence on fossil fuels. They are now thinking of turning stray forms of energy such as noise or random vibrations from the environment into useful form of energy. They want to use piezoelectric effect for such purposes. Some materials produce electricity while undergoing mechanical stress.

This is known as piezoelectric effect. Small piezoelectric crystals can come up with enough voltage to create a spark which can be utilized to ignite gas. By taking nanocrystals of zinc oxide and barium titanate. These two nanocrystals were put in water. When these crystals received ultrasonic vibrations, the nanofibers flexed and catalyzed a chemical reaction. This whole process resulted in splitting the water molecules into hydrogen and oxygen.

It has been noted that smaller fibers exhibit more flexibility than larger crystals. Therefore smaller fibers can generate electric charges without difficulty. The project team has extracted an impressive 18 percent efficiency with the nanocrystals, higher than most experimental energy sources because we can tune the fiber and plate sizes, we can use even small amounts of [mechanical] noise — like a vibration or water flowing — to bend the fibers and plates. With this kind of technology, we can scavenge energy waste and convert it into useful chemical energy.

But scientists didn’t utilize this electrical energy straightaway. They use this energy in breaking the chemical bonds in water to split oxygen and hydrogen. This is a new phenomenon, converting mechanical energy directly to chemical energy. It is a piezoelectrochemical (PZEC) effect. Why it seems that scientists are beating around the bush? Because chemical energy of hydrogen fuel is more stable than the electric charge. Storage of hydrogen fuel is easy and would not lose potency over time.

We have limited areas to collect large energy differences, like a waterfall or a big dam. But we have lots of places with small energies. If we can harvest that energy, it would be tremendous.

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