Surya Shakti ........The Solar Energy

Solar energy is the least polluting and most inexaustable of all known energy sources. We are only beginning to realize its potential. While solar energy has always been available to us, we have not used it effectively. Mainly because getting a reliable energy supply from the Sun can be a technical and difficult looking task.

But, not all solar systems are difficult to build or use.

Today

Several solar energy systems are in use. The two most common are solar water heaters and small stand-alone photovoltaic systems. They also demonstrate the two main techniques of harnessing solar energy: solar thermal systems, and solar electric systems. The solar thermal systems convert the radiant energy of the sun into heat, and then use that heat energy as desired. The solar electric systems convert the radiant energy of the sun directly into electrical energy, which can then be used as most electrical energy is used today.

Tomorrow

Several applications of solar energy may be used in the near future. Some of these are Solar cooking, Solar chemical energy storage, Solar steam generation and Solar incinerators.

The Challenge

Solar energy at the Earth's surface varies in many ways, and on varying time scales. Most uses of energy require constant and readily available energy. The greatest challenge to the designer of solar energy systems is to provide means store it when available, so that it will be available when needed.

The second great challenge is to make a device to capture the solar energy in the form of radiation, and to convert it to a useful form of energy. The amount of energy falling on a flat level surface one meter square over the course of one day is roughly 5 killowatt hours. This averages in 24 hours to about 0.2 kWh/m2. When compared to other modern energy sources, this is not very concentrated. For example a 100 Watt light bulb at its surface has an intensity of about 12 kW/m2 and an electric stove (500W burner) has an intensity of about 25 kW/m2. Thus solar energy systems need to have collectors over a relatively large area compared to other energy sources we are familiar with.

The third great challenge is the economics. While the concepts of collection and storage of solar energy are simple, those collectors and that storage must be built with real materials, and must compete economically in a world where already inexpensive and subsidised energy sources exist.

Time for solar cookers has come.

"On the first day, the women walk to the nearest place where wood can be gathered.
On the second day, they search for firewood.
The third day is spent carrying the wood on their backs to the village"

- from Chad, Africa

Every minute the world has 200 more people and 20 hectares less forest. 45% of the world's wood is used as fuel and already 1.5 billion people suffer fuelwood shortages. The United Nations predicts this number will grow to 2.4 billion by the year 2000. Deforestation brings desertification and many other problems. Solar cooking goes a long way toward solving these serious problems.

"The world can choose sunlight or further deforestation, solar cooking or widespread starvation." - Audubon Magazine