Earth Day Special | The math and magic of solar energy

Earth Day Special | The math and magic of solar energy
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First Published: Tue, Apr 22 2008. 01 16 PM IST

Updated: Tue, Apr 22 2008. 01 16 PM IST
New Delhi: The energy produced by the sun in a single second is enough to meet the needs of all humanity for 2000 years. “The surface of the Earth receives an amount of solar energy equivalent to roughly 10,000 times the world energy demand,” wrote Erik Lysen in the January 2003 issue of Renewable Energy World magazine.
So what stops us from using this abundant energy? “Understanding”, says Ruchi Bhambri, director, Bhambri Solar Enterprises, a New Delhi based exporter, manufacturer, supplier and importer of solar energy products.
“People are resistant to shift from conventional to non-conventional energy sources. Solar or any other renewable energy needs an understanding —of the product, of its positive impact on environment, of how useful it could be to the end user. The more the understanding, the better the acceptance and satisfaction,” Bhambri adds.
Abhay Majumdar agrees. Based out of Nashik, Majumdar is a mechanical engineer and runs Technophile, a product promotion firm that deals with solar and wind energy based products.
“The response to solar energy products is on increase, but not at the expected rate. There is lack of general awareness and there are some misconceptions such as hot water would be available only on sunny days and would not be available in the evening or early morning,” Majumdar exclaims.
The Indian government is doing its bit to facilitate the promotion of solar products, but the implementation is poor, feels Majumdar.
As per the Ministry of New and Renewable Energy (MNRE) records, a total of 33 grid interactive solar photovoltaic power plants have been installed in the country with financial support from the Government, as of 31 March, 2008. These plants, with aggregate capacity of 2.12 megawatt, are estimated to generate about 2.55 million units of electricity a year.
In addition, around 14.5 lakh decentralized off-grid solar photovoltaic systems aggregating to about 125MW capacity have been installed in the country, and are capable of generating 150 million units in a year. Further, a collector area of about 2.15 million square meters has been installed for solar water heating applications.
A total of 60,000 SPV home-lighting systems, 6000 SPV street lights and 27,500 solar lanterns were allocated to various states and UTs till 31 December 2006. While during the year 2007-08, around 63,250 solar home lighting systems, 7,000 solar streetlights and 94,000 solar lanterns were sanctioned to various states and UTs. The involved implementation agencies are allowed to complete the installation by 30 June 2008.
Solar water heating systems have been made mandatory by the government in hospitals. “But, a big hospital with a 100 liters capacity solar water heater does not solve the purpose at all. It’s just an eyewash,” says Bhambri.
Similarly, the government may have identified banks and non-banking financial corporations to support interested people with loans for renewable energy products.
Majumdar says nationalized banks are reluctant to disburse soft loans for solar water heating systems because they find the procedures tedious and loan amounts small. They are also reluctant to consider case of a person who does not have account in their bank.
Another situation government agencies and NGOs involved in awareness programmes can take care of is unscrupulous dealers who sell normal water heating systems that are not able to handle hard water. The systems stop working after some time creating a wrong impression about solar products.
Typically, a solar water heating system with 2 sq. m. of collector area can generate energy equivalent to up to 1,500 units of electricity when the system is used for 300 days a year.
As far as common man is concerned, he must go for water heating systems without giving a second thought, Majumdar suggests. It is free from dangers as posed by electric and LPG geysers, the cost of running is low, it is virtually a maintenance free system as there are no moving parts, no operation is involved and it pays back in three or four years (depending on use) by way of saving on electricity.
For rural and interior areas, solar LED (light emitting diodes) based lighting products are useful as you are comparing a situation of no light and light. The cost of solar products has gone down.
A LED based solar lantern comes for Rs500 to Rs2,000 depending on back up time, which could range from 2 hours to 12 hours. If you compare it with the amount of kerosene oil spent everyday, your lantern would recover the cost in less than two years.
In any case, inverters are becoming useless in interiors, as the power availability is not sufficient there to charge the batteries.
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First Published: Tue, Apr 22 2008. 01 16 PM IST