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Challenges of PV

  • 14/12/2008

The main component that converts photons into electricity in a solar PV is the layer of silicon semiconductors. In 2007, the solar PV industry along with the semiconductor industry consumed some 38,000 tonnes of poly-silicon. This grew to 58,000 tonnes in 2007. Increasing demand has led to price jump of more than 100 per cent from US $20 per kg in 2001 to US $50 in 2006.

The future of PV industry depends on two factors: bringing down the cost of the panels and increasing their efficiency. Currently, the panels use about 10 gms of polycrystalline silicon to produce 1 W/p (watt/peak) of energy, which is down from 13 gms a few years ago. The efficiency of solar panels has grown from 10 per cent in the 1990s to more than 13 per cent at present. The monocrystalline cells have recorded efficiencies of almost 25 per cent under lab conditions, while polycrystalline cells have surpassed 18 per cent. Researchers are now trying to target PV cells that can function at 30 to 60 per cent efficiency. One such technology is the concentrated photovoltaic cells. There are also other technologies which are beyond conventional junction semiconductors and use photoelectrochemicals, polymers and dyes.

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