Prof D Chandrasekharam

‘’The National Solar Mission has set a target of 20,000 MW of solar electricity by 2020. This may be desirable, but at today’s solar technology costs, it will be economic suicide…..” comments Swaminathan S Anklesaria Aiyar in Times of India ( 8 Aug 2010). A 1MWe solar PV needs 6 to 10 acres of land and a 100 MWe PV solar power plant needs 600 to 1000 acres of land. (1 acre is equal to 4047 sq. m or 43200 sq. ft). In fact the world is hopeful of getting a break through in Solar PV but that did not happen even after 30 years of research. To generate power from solar PV, an intermediate device is needed. This devise heavily depends on single crystalline (more efficient), polycrystalline and amorphous silicon. These are processed from quartz. Where do we get pure quartz?. Geologists very well know the mechanism of natural amorphous silica formation but the technocrats think that this can be manufactured like pharma drugs in any laboratory. Solar PV remains, according to S  A Aiyar, “hopelessly uneconomical even today”. To day power generated from roof top solar PV coasts any where between Rs. 9 to 10/ unit*. Technological breakthrough hopefully may bring the unit coast crashing down in the coming decade.   All the major Western and European companies involved in the manufacture of PV cells are pushing millions of rupees to keep solar PV hype at high level for their own survival. S A Aiyar puts this truth in his sarcastic comment……..  “Swami the Government. knows all this. But it needs to do something in global climate negotiations. The US will not come on board unless China and India are seen contributing, and with out US participation the climate talks will fall. So we have made a fancy long term projections 20,000 MW by 2020, 100,000 MW by 2030- getting good publicity. But our near0term target of 1000 MW by 2013 implies no more than some pilot projects. This will keep climate negotiations going at little cost”” Solar PV and Solar thermal are land intensive and site specific. It may be possible to get large stretch of land in Rajasthan desert to install solar power plants. But where do we get water for cooling towers? and to clean the dust over the panels to maintain efficiency?

 Solar PV and wind are very popular in Sub-Sahara countries, although the unit cost is much higher compared to thermal. For example, the levelized grid supplied cost of solar PV is about 16 to 50 US cents in areas with good net work connectivity while the cost escalates to one dollar per unit in remote areas in Ethiopia.   Diesel generated power costs little over 70 US cents per unit. Thus diesel and solar PV are on par with each other as for as cost is concerned. The only difference is diesel has to be transported from the nearest sea port Djibouti, which is several hundreds of kilometers away from Ethiopia. 

 Compared to solar PV, geothermal power in Ethiopia is very competitive to all the renewable and with an estimated resources of 60000 MWe spread over the entire East African Rift  valley.  The Aluto Lungano geothermal field alone is capable of generating 500 MWe. Unit cost of geothermal power is about seven US cents. The advantage here is to have local grid systems that can supply power to clusters of rural areas. Small geothermal power plants that can generate 5 to 10 MWe are most suitable and cost effective in the entire rift valley.  A 5 MWe geothermal power plant may need only one acre of land (1 acre is equal to 4047 sq. m or 43200 sq. ft). This is far less compared to the land requirement of solar. In future, with the hot dry rock technology taking shape, power can be generated in everyone’s back yard! Let’s hope that this will happen before the next young generation retires!

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*According to a recent news article “ Few takers for pricey solar power in Delhi” published in TOI, 13^th Sept. 2010,  the solar power will costs Rs. 19.50 per unit. With Govt. subsidy consumers can pay Rs. 5.50 per unit.