The Sun is believed to be 4.6 billion years old and it has never ever failed to show up. No one owns the sun and yet everyone owns it. It supplies its energy free to all who wish to take it. Supplies are inexhaustible. There are no rate hikes. In fact, no rates at all and no one holds or can hold any rights or monopoly over it. It is 93 million miles away. It takes only eight minutes for it to arrive at earth. In fact, it is always here in some part of the earth. It is the biggest reactor the world can ever have but it leaves no radio active wastes or any kind of pollution. In spite of all these attributes, it remains broadly untapped as a source of electric power supply. Only very recently, harnessing solar energy has sparked great interest the world over for the following serious concerns: 1) Impending global environmental disaster because of relentless use of fossil fuels, burning of coal for power generation and resultant enormous emission of carbon dioxide (CO2) and other toxic residuals; 2) Uncertain and unsteady supplies of crude oil because of political and social instability and 3) Steeply rising cost of crude oil and natural gas. Crude oil, coal and natural gas with proven or unproven reserves are finite quantities, which will last only for a few more decades. Supplies are diminishing as demand for these commodities is constantly growing the world over, at an alarming rate. China and India are the relatively new massive gobblers of fossil fuels as their economies accelerate. The United States is the largest consumer of fossil fuels and the biggest emitter of global pollution. India is the fourth largest emitter of carbon dioxide after the US, China and Russia. In the long haul, fossil fuels are not sustainable and cannot be relied upon for ever. Therefore, there has to be transformation of economies by switching over to the abundant and endless supply of renewable energy. Nature is awash with such renewable, eco-friendly energy sources. Energy that reaches earth from sunlight in one hour is more than that which is used by all human activities on the earth in the whole one year. The sun has been used for drying clothes, ripening of harvests, fruits and vegetables, baking bricks to build monuments and homes for centuries. It is only recently that the sun is being exploited to generate electricity to power light in homes and buildings, in streets and towns, in addition to heating and cooling homes and buildings, running tractors, helping drawing water for irrigation purposes and so on. Fortunately, there are now a host of technologies for tapping into solar power, servicing a variety of fields. Advanced technologies and energy resources are now available to build sustainable solar and wind based economy that can reduce dependence on oil and improve global climate. Electricity produced through wind energy is an indirect form of solar energy because it is the temperature variations that drive turbines. Getting energy from the wind is as old as the invention of sails for boats. The Romans used windmills to grind grain and the Dutch used windmills for agricultural and domestic uses, including water diversion. What are the various ways in which the sun's energy is tapped? There are three well established ways of doing so. The first is by using solar cells, called photovoltaic or photoelectric cells, that convert light directly into electricity. A basic solar power system consists of a photovoltaic module, an inverter for converting direct current into alternating current, and peripheral devices including a controller. A residential solar power system has the highest conversion efficiency rating of about 16 per cent. A photovoltaic cell is a non-mechanical device usually made from silicon alloys. The second is solar water heating, where heat from the sun is used to heat water in glass panels over the roof. Flat plate and evacuated tube collectors have efficiencies of about 60 per cent during normal operating conditions. The third way is by solar furnaces, which use a huge array of mirrors to concentrate the sun's energy into a small space to produce high temperatures. The heat is used to generate steam, which then turns turbines, which in turn drives generators to produce electric power. The photovoltaic cell was discovered in 1954 by a US company, at that time known as the Bell Telephone Company, while researching sensitivity of a properly prepared silicon wafer to sunlight. For the first time, in 1958, use of photovoltaic modules as power source for a Vanguard satellite was successfully applied. Thin film solar formula, a relatively new technology in which cells are created in roughly the same way that memory is created on dense storage devise like hard disk devices, is less costly but has a long way to go before it can increase its energy output to compete with silicon. Thin, sleek new technology, however, will one day be applied on windows of skyscrapers and high rise apartment buildings, harnessing energy for exterior and interior lighting, heating, and cooling to provide comfortable working and living environments. It is attractive and cheaper than bulkier solar panels made from silicon. Currently, average crystalline silicon solar cell module has an efficiency of about 16 per cent while an average thin film cell solar module has efficiency of about 6 per cent. However, thin film manufacturing costs are potentially lower and progressive increases in efficiencies and manufacturing economies would over foreseeable time make them easily marketable product.