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Harnessing Solar Energy in Orissa
"With a total land area of 155,707 square kilometres, Orissa holds a vast potential for harnessing very large quantities of solar power. Moreover, large portions of the western part of the state are in rain shadow areas, which receive solar radiation round the year without any interruption at all."
Dr. Nachiketa Das : March 20, 2008
The sun unconditionally and continuously beams vast amounts of energy to our planet earth that sustains us. The ultimate source of any form of energy we use, except for nuclear energy, is the sun. The solar energy reaching the earth, in technical language is termed insolation, which in fact is an abbreviation for incoming solar radiation.
The intensity of insolation varies, maximum being in mid-day when the sun is directly overhead, and minimum when the sun is low down the horizon while rising or setting. Insolation similarly varies during the year and the summer months have the highest values. Different parts of the globe also have different levels of insolation. The tropical landmasses have the highest insolation, which progressively declines as the latitudes rise. Thus the countries in high latitudes, say in northern Europe, have much lower insolation when compared with a subtropical country like India. For example the average annual insolation of Bombay (whose latitude is 19oN) is 5.28 kW-h/m2/day and that of Barcelona in Spain (latitude 42oN) is 4.6 and London (latitude 52oN) is 2.6. The average annual insolation for Orissa would be between 5 to 6 kW-h/m2/day, which is very high.
These days we harness this incoming solar radiation in two main ways, the first being thermal, when water or some other fluid is heated to produce steam to drive turbines to generate electricity. The second method involves direct conversion of the solar energy into electricity by photovoltaic cells, which are also known as solar cells.
Potential of solar energy in Orissa:
Orissa, because of its sub-tropical geographical location between the latitudes of 17 to 23oN, receives an abundance of solar radiation throughout the year except for some interruption during the monsoon and winter seasons. With a total land area of 155,707 square kilometres, Orissa holds a vast potential for harnessing very large quantities of solar power. Moreover, large portions of the western part of the state, far away from the coasts, are in rain shadow areas, which receive solar radiation round the year, virtually, without any interruption. Orissa Renewable Energy Development Agency (OREDA) in its website states that the potential of solar photovoltaic power of Orissa is 14,000 MW, which is a very conservative estimate. In any case, when this figure is compared with say the 300 MW of electricity generated by the country’s largest hydroelectric dam Hirakud of Orissa, the enormous potential of solar power is demonstrated.
Some folklores of Orissa described a crude form of harnessing solar power in the past. In hot summer months, the cowherds tending their cattle on the grazing grounds of the riverbanks cooked their simple meals of rice in milk by solar energy. They would seal a pot containing rice and milk and bury it in the hot loose sands of the river beds, where it got cooked, albeit slowly. The pots with the lids served as a crude version of a solar oven. No one in Orissa took any further interest in developing technologies for harnessing solar power, whereas the western nations forged ahead and developed solar ovens, solar cookers and a range of other gadgets that harness solar energy. Much improved versions of solar cookers are routinely employed these days in the southern European nations of Spain and Portugal. In Orissa, OREDA was established in 1984 to harness solar energy, which now manufactures solar cookers, solar lanterns, solar water heaters, and solar photovoltaic cells for street lighting.
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Efficiency of solar cells:
Efficiency of photovoltaic cells, which is a lowly 6 to 12%, is the major problem at the moment, which makes power generation by solar energy 2 to 5 times more expensive than the conventional sources. High cost of silicon, which is the key component for making the solar cells, is the prime factor that makes solar energy costly. Currently large investments are taking place in the production of silicon and that makes the analysts believe that by 2009 costs of silicon will start falling. Some researchers are developing alternate products such as very fine copper to harness solar energy, which may cut down the costs very significantly.
Many people still think that harnessing solar energy is restricted to a few roof top solar panels for hot water. That is a major use at the moment, and so it should be, considering the amount of energy people use to heat water for daily ablutions. If every roof top hosts solar panels, and every household gets its hot water from solar energy, vast amounts of electricity generated from conventional sources would be saved. Roof top solar panels can generate electricity for lighting purposes too. On top of these, solar power can also generate electricity in a much bigger scale, which can be fed into the power grid. In California and in Spain large-scale solar energy plants generate electricity from steam driven turbines with output in excess of 1 MW.
On the 30th of March 2007, a huge solar plant generating 11 MW of power near Seville in Spain was inaugurated. This plant generates electricity by concentrating solar radiation on to the top portion of a 115 metre high tower that hosts a solar receiver and the turbine. 624 large movable mirrors called heliostats, each measuring 120 square metres, concentrate and beam the solar energy on to the tower. Power plants like this in suitable locations can generate vast quantities of electricity.
China’s Sun Shine Boy:
A Chinese Australian billionaire by the name Dr Shi Jhengrong, admiringly called ‘China’s sun shine boy’ by the international press, made his billions by selling solar cells. His rise has been truly spectacular, and his success is a fine demonstration of the potential solar power holds for producing electricity and creating wealth. A brief account of this 43-year-old entrepreneur will not be out of place.
In the late 1980s, Shi Jhengrong, a student of physics from China went to Australia for higher studies. There he enrolled for a Ph.D. course at the University of NSW located in Sydney. Quite by chance, he ended up doing research on solar energy, and as a student his dream was to get the degree, publish a few articles in scientific journals, and look for a scientific job. In one of his television interviews he mentioned that he even contemplated starting a small Chinese restaurant in Sydney in case he did not get a job. He completed his Ph.D., and visited China in the mid-1990s on lecture tours. The pace of growth he saw in China impressed him, so much so, that in 2001, to the surprise of his friends in Sydney, he moved to China with his wife and the two Australian born children. In China he set up a company by the name Suntech Power to produce solar cells. Soon afterwards, the local government of Wuxi, located in the outskirts of Sanghai, financed Dr Shi to the tune of $6 million, and helped him obtain an additional research grant of $5 million. Suntech Power started functioning with a grand total of 20 employees.
In 2005 Suntech Power went public at New York Stock Exchange where it raised $455 million to fund further expansions. In 2007 this NASDAQ listed company was capitalised at around $5.5 billion, and Dr Shi owns about 40% of the shares, which makes him a multibillionaire. Well done Dr Shi, or as the Australians say ‘good on you Dr Shi’.
In 2006 Suntech Power was the fourth largest producer of solar cells in the world. Japanese behemoth Sharp remains the largest producer and the market leader. Suntech’s main markets are Japan, Germany and Spain, with China purchasing only 10% of the production. The market for solar cells is expected to grow at the rate of 20 to 40% annually.
Application Of Nanotechnology:
The next great leap forward in harnessing solar energy will come with the introduction of nanotechnology and the tiny plastic solar cells, which will raise the efficiency of the collectors to as high as 30%. The efficiencies of these collectors would be 3 to 5 times more than the current photovoltaic solar cells that are used to make the traditional silicon solar panels, which are bulky, heavy, inefficient and costly. Moreover the plastic solar cells can even function on cloudy days. Although it sounds miraculous, it is possible because at present the solar cells harness only the radiation of the visible spectrum which is only 50% of the total radiation, and the rest 50% is in the infrared range, which goes unutilised. The infrared radiation is not obstructed by the cloud cover, and could be harnessed by the new generation cells produced by nanotechnology. These plastic cells can be sprayed like spray paints on to a range of surfaces including roof tops, mats and even clothes for harnessing solar energy.
Public policy to harness solar power:
Government of Orissa should make a policy decision of mandatory installation of solar panels on the roofs of all new constructions of government buildings. The government may also subsidize installation of systems that harness solar energy on private buildings. Such regulations will give a tremendous boost to the manufacturing of solar cells and the harnessing of solar energy.
OREDA should actively consider utilising nanotechnology for the great leap forward in harnessing solar power in Orissa.
(Author is the Director, NRI-Enviro-Geo-Tech - Australia, Sydney & presently based in Hiroshima, Japan)