Renewable Sources of Energy: Prospects and Issues
Solar Energy
Solar energy is produced when sunlight is used to generate electrical energy. Photovoltaic (PV) panels use silicon cells, which transform solar radiation into direct current. The energy is used simultaneously (for example to pump water) or is stored in batteries to provide electricity. Solar energy can also be used to cook food by trapping and concentrating the sun's heat in a cooker, and to heat water or to generate steam which, in turn, can be utilised for mechanical applications. This is usually done by flat plate collectors which is expose a large thin surface, containing a liquid, to the sun. The sun's heat can be intensified with lenses and mirrors and stored in salts and stones. Solar energy is still not viable on economic front to many developing countries therefore its use is promoted by various agencies. The World Bank has a program to install home lighting system in 200,000 homes to Indonesia. Of the 200 million Indonesian, 60 million people still rely on kerosene for lighting.
Box 1: Energy consumption pattern in Kolar
A detailed study of rural Kolar reveals that, about 84% of the energy need in the district is satisfied by bioenergy and its use is not sustainable. Bioenergy in use, mainly constitute twigs and branches of the locally available species, agriculture residue mainly from Sericulture activity and cattle dung. Domestic firewood need ranges from 1.7 to 2.5 kg per person per day, which is on higher side when compare to the state average of 1.7 kg/person/day. Higher level of consumption is mainly due to inefficient traditional cookstoves. Use of kerosene and electricity use is restricted due economic and availability constraints and need is 0.72 litre/person/month and 1.16 kWh/person/month respectively. [2] Animate energy in the form of human energy contributes significantly in domestic sector. Domestic activities such as cooking, fuel collection and chopping, fetching water, cloth washing, utensils washing, marketing etc, consumes as much as 7.74 hrs/day/household. Women contribute about 5.6 hrs, men and child contributes 1.12 and 1.02 hrs respectively. [3]
Box 2: Solar energy scenario in Kolar
Solar energy use in rural Kolar is almost negligible. But rural population is aware of solar technology and very much interested to see and know more about solar equipment. Many place people are even ready to go for solar equipment, but unfortunately they are handicapped with the knowledge of market and related issues. Urban Kolar also is as bad as rural in solar energy use as there is not much progress in spite of market opportunities. Only some commercial firms like Hotels, hostels are using solar thermal water heaters for their water heating needs. Even some households have installed solar water heaters, but their spread is negligible. A recent installation of solar lighting system at Chinmayaswamy temple, Chokkahalli, Kolar is a progressive step taken by KSCST (Karnataka State Council for Science and Technology). Kolar is hotter districts of Karnataka and has a good potential for solar energy development. Promotion of solar energy from Govt. side can bring in some major changes in energy sector.
Solar Potential in Kolar:
The empirical relationships between global radiation (GR) and climatological parameters such as sunshine mean daily temperature, relative humidity, specific humidity, minimum and maximum temperature and rainfall (based on data at Bangalore) are used to compute global radiation (GR-kWh/Sq.m.) for Kolar. Kolar has GR range of 5.2-6.77 during January-May and is in range of 4.6 - 5.1 during monsoon months, July-September.
The Dominican Republic is another example of growing rural PV market. Currently there are five NGO’s providing revolving credits for the purchase of $400 to $800 solar home systems. Japan is providing generous subsidy for roof top solar power system, which has led to solar boom. About 9400 solar home systems were installed in 1997 and the number is expected to reach 70000 mark by the year 2000. Europe and US have launched ambitious solar power program. Each has announced a million roof initiatives to boost the domestic system market. Around the world there are many projects utilising PV in such diverse climates, cultures and economies as Germany, with 200 homes, the US Department of Energy sponsoring a rural electrification project in Brazil for 500,000 homes. There are 100,000 families in rural developing countries of Dominican Republic, Kenya, Sri Lanka and Zimbabwe, all using PV power for lighting, radio and television. [4]
India also is making its mark in solar energy development and use. India lies in the sunny regions of the world. Most part of the country receives 4 to 7 kWh of solar radiation per square meter per day, with 250 to 300 sunny days in a year. This make India potential area in solar energy. As a result solar energy development is seen all over the country. Auroville(Pondiecherry) has successfully tried solar energy options. As a result there are more than 100 houses fully equipped with PV panels and 35 houses using solar power in conjunction with a Tamil Nadu Electricity Board grid connection. In July 1996, the capacity of photovoltaics in Auroville was a total of 150 kWh. Most of the PV panels are manufactured in India. These panels are used for home lighting systems, solar pumping for drinking water and agriculture, and solar hybrid power systems. In 1994-96, 185 solar pumps were installed in Auroville and different parts of India by CSR. Of these, 150 are operating in Auroville and nearby areas. Further examples of the use of solar power in Auroville are solar hot water systems, solar cookers and solar dryers for food processing. Other solar applications developed are solar curing chambers for ferrocement-prefabricated elements, solar concentrators, and solar dryers for curing wood. In a town like Auroville, where many houses are partly or fully powered by energy generated by solar photovoltaic panels, and where even a large complex like the Visitors. Centre runs entirely on solar, it is perhaps not revolutionary any more to imagine a big kitchen providing lunches and dinners for up to a thousand people using mainly solar energy. HUDCO has sanctioned Rs.1 million ($30,000) for the buildings, and the Ministry for Non-Conventional Energy Sources (MNES) granted Rs.1.5 million ($45,000) for the solar bowl and
a fully automatic hybrid boiler. In addition, several of Auroville's larger commercial units and individual Aurovilians have been given the financial assistance. One hundred Micro Solar Lighting Systems, named "Solux II", were imported from Germany by Computer Aided Research and Engineering (CARE), a unit of the CSR. CARE wants to explore the market for Solux II and see if it could be manufactured in India using indigenous parts, and sold at a reasonable cost. The solar power program seeks to produce grid quality power using solar thermal and solar photovoltaic technologies. A 140 MW capacity solar thermal power project is coming up in Rajasthan as a centrally assisted project. In the solar photovoltaic power program, 11 projects with an aggregate installed capacity of 810 MW are now functioning satisfactorily. Of these five are in Tamil Nadu, two in U.P., one each in Maharashtra, Madhya Pradesh, Karnataka and West Bengal. The main problem with solar power is that it has not yet reached the stage of commercial viability. But with Govt. initiatives and subsidy it can be brought in commercial use.
SELF (Solar Electric Light Fund, Inc.) operates a rural solar enterprise in Karnataka, which provides solar services to rural households, and arrange financing and leasing of solar electric system.
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Solar Energy