July 15, 2013, 8:32 pm


Solar energy is the technology used to harness the sun’s energy and make it useable. It is also the most important of the non-conventional sources of energy because it is non-polluting and, therefore, helps lessen the greenhouse effect. Solar energy has been used since prehistoric times, but in a most primitive manner. Before 1970, some research had been carried out in a few countries to harness solar energy more efficiently, but most of this work remained mostly academic. After the dramatic rise in oil prices in the 1970s, several countries began to conduct extensive research in a bid to tap solar energy.


Every hour the sun releases enough energy to satisfy global energy needs for one year. When we hang out our clothes to dry in the sun, we use the energy of the sun. In the same way, solar panels absorb the energy of the sun to provide heat for cooking etc. Today, the technology produces less than one tenth of one percent of global energy demand. Many people are familiar with so-called photovoltaic cells, or solar panels, found on things like spacecraft, rooftops, and handheld calculators. The cells are made of semiconductor materials like those found in computer chips. When sunlight falls on the cells, it knocks electrons loose from their atoms. As the electrons flow through the cell, they generate electricity.


In the next few years it is expected that millions of households in the world will be using solar energy as the current trends in USA and Japan show. The Indian Renewable Energy Development Agency and the Ministry of Non-Conventional Energy Sources are formulating a programme to have solar energy in more than a million households in the next few years.


Solar energy can also be used to meet our electricity requirements. Through Solar Photovoltaic (SPV) cells, solar radiation gets converted into DC electricity directly. This electricity can either be used as it is or can be stored in the battery. SPV can be used for a number of applications such as domestic lighting; street lighting; village electrification; water pumping; desalination of sea water; powering of remote telecommunication repeater stations and railway signals.


In Sri Lanka, the development of solar energy as a renewable energy source would save money in the long run, create more jobs, eliminate the need for oil imports, cause less pollution and environmental degradation and also increase economic security especially in rural areas.


Micro-finance is becoming popular in countries such as Kenya to combat the initial high costs of installing PV systems. Kenya currently has a strong un-subsidized market, wherein the public can obtain low power (10-20W) "entry level" modules. Once the payment for the initial installation has been made, the investment will simply pay for itself for the rest of its life span.


Shari Jayawardhana

island.lk