What is Solar Energy?

For billions of years the sun has been producing vast amounts of power through nuclear fusion. This is the process by which four hydrogen atoms combine to produce one helium atom. This is the mechanism that the sun uses to generate its energy.

The amount of energy from the sun that reaches the Earth is vast. All the energy that can be produced by the non-renewable reserves of the world like petroleum, coal, and natural gas is equaled by just twenty days of sunshine.

Short answer: the light and heat provided by the sun. A slightly longer answer: after running the gauntlet from an average of 93 million miles away, through the various layers of atmosphere and atmospheric conditions (clouds, pollutants, dust and the like), about half of the solar energy is absorbed by water and land, with the other half reflected and re-radiated back into space. The half that makes it is absorbed by oceans, land masses and plants; in the ocean, the energy drives heat and wind-driven currents (like the Gulf Stream); on land, the energy is absorbed and creates heat, and the little bit that's left is absorbed by plants and converted to chemical energy through a process we all know as photosynthesis.

THE POWER OF SUN

If measured outside of our atmosphere the energy that reaches Earth has about 1,300 watts per square meter. This energy is in radiant form and about a third of it is reflected back into space. A certain amount is absorbed by the atmosphere which is the primary cause of weather.

 

Ultimately the energy that reaches the surface of the Earth averages out to about 1,000 watts per square meter on a cloudless day. Of course some arid and desert areas receive more. This means that on a 24-hour day the energy that reaches earth is equivalent to one barrel of oil every year per square meter.

These numbers stand for the maximum energy that reaches the Earth from the sun but current technology allows only a small amount of this energy to be collected and converted to other forms of energy which can be more readily used.
 

HAVE A USED ANY KIND OF SOLAR ENERGY BEFORE?

Solar power has been harnessed by humans since ancient times. The technology that has been used to harness solar energy has been evolving since then. Since the use of the oculus at the Parthenon in Rome delighting techniques have been used by ancient architects. Natural light has been dominant method in the history of lighting.

During the industrial revolution the use of coal had increased steadily and has shifted from wood and other kinds of biomass to fossil fuels. In the 1860?s there was the expectation that coal would soon be exhausted as a power source so there was research conducted into solar power. However during the early part of the 20th century the development and research of solar power slowed and stopped because of the increasing availability and cost effectiveness of coal and petroleum at the time.

In 1973 during the oil embargo and the 1979 energy crisis there was a review and reorganization of energy policies around the world and especially in the industrialized countries. This brought new life to solar power research and development of solar power technologies.

 

THE FUTURE

The technologies used in harnessing solar power are on the verge of rapid growth and development in the 21st century. Architects and engineers are increasingly aware of the advantages of building in passive solar power into their designs.

The cost of solar water heaters is becoming increasingly competitive with more conventional water heaters in certain areas. Photovoltaic technology is slowly becoming a cheap way of generating electricity.

 

ENERGY OUR ADDICTION TO FOSSIL FUEL

Of course the expansion of solar power industry will encounter some problems but these can be overcome. In spite of difficulties put up by some utilities for grid connected photovoltaic systems there will be increased use of these technologies and solar power will be increasingly crucial in ending our addiction to fossil fuels and fighting the threat of global warming and assuring a future based on renewable and clean energy.