Critical lighting and communications are major applications, even though you see these being used for applications like rail signalling, cathodic
protection of underground pipelines & vessels, geophysical/oilfield instrumentation, etc. Very few civilian use installations exceed 100 Watts.
Production has reached 20 MW annually, between nine manufacturers. Yet, considering a total renewable energy production of 3500 MW, SPV has a very small share. Its high cost and poor conversion efficiency make it affordable only where the cost of not having any power is greater than the cost of a SPV system. Here too, wind and biomass provide better alternatives in cost terms.
SPV is excellent for low-power-high-quality power in remote locations, esp. where fuel is not available as in a desert, or where noise and cables are not affordable for safety/security reasons, like military and mobile installations.
Reliability is no major issue - plenty of information and tech resources are available. While silver solder materials are locally availed and importable, I have made panels using very crude processes in the 80s, which continue to embarass me by their living presence! It is however critical to ensure that
silicon cells do not get exposed to oxygen, being highly reactive, from the time they are unpacked. And here lies a difficulty in producing panels. The
controlled environment means a scale for economy.
Before Liberalisation of the 90s by the Narsimha Rao govt., no one outside the public sector was even allowed to sell a development, let alone produce
anything photovoltaic, except at system level. This has since changed radically.
Solar cells are largely imported while Mettur Industries manufactures silicon and few companies like Udhaya Semiconductors Ltd, CEL, BHEL, RES/Microsol etc 'cut' the silicon sheets into strips and fabrcate the solar cells. Panels are also made by these companies. As for total systems, Tata BP Solar is about the world's largest producer, with a turnover of Rs 2 Billion as of 2001-02.
Hence, SPV in India is a mature and growing industry, with plenty of upward scope.
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