Maybe because they realized the importance of the energy of the sun. As we enter the 21st century, we look back, after all our malpractices which have almost destroyed our planet, at what the ancients had figured out way before than we did: To value the energy of the sun.

It is the relentless energy of the sun, which it has in store aplenty to light the world for many generations to come, and its advantages are numerous. Consider some of them to have an idea about them.

Free Forever

The sun has been providing its energy to the tenants of planet Earth for millennia now, and is continuing to do so. It is up to us to utilize this energy, which is available without any charge.

Earlier civilizations like the Greek and the Egyptians are known to have used the energy from the sun. It should act as an inspiration for the modern civilization.

Environment-Friendly

The process of using energy from the sun is environment-friendly and completely free of any pollution whatsoever, let it be environmental or noise pollution. It is much safer, simple and cost-effective than expensive and hazardous means of power generation like using fossil fuels, which give away carbon emissions and other greenhouse gases that are deteriorating the condition of our atmosphere, and our planet is increasingly being affected by global warming, which is a proven threat.

Reliability

There are no questions whatsoever about the reliability and availability of the energy from sun. The sun has been around for billions of years, and will continue to carry on its works for even billions of years further. And it provides us energy every day to light our part of the world, and does the same job on the other parts of the globe when it sets in the areas you are living in. Unlike other energy sources, the solar energy is always available on a good portion of the populated land, and it is up to us to utilize it to the fullest.

Unlimited Potential

If properly addressed and worked on, with technological advances, we can potentially settle all the power problems of the world through one source, the energy from the sun. If you consider it, the potential of the energy of the sun that can be exploited for power generation is unlimited, and yet the current power production from solar energy constitutes even less than 1%. In fact, the solar energy that falls on Earth after every 8 minutes is enough to fulfill the power requirements of the United States for the whole year. Although it is not actually possible to utilize absolutely the entire solar energy that reaches the surface on the earth, but we are no where near as well.

Why Realizing So Late?

Yes, the ancients knew it, but how come we did not figure it out for centuries? Why cannot we effectively and efficiently use the immense amount of energy from the sun? Why such a huge amount of solar energy is being wasted every single day?

The greatest reason for those questions is the fact that the sunlight reaching the surface of the Earth is so sparsely scattered that it is not easy capturing it to be utilized for our energy needs as efficiently as its potential.

In order to create a substantial difference in successfully utilizing the solar energy for our use is to develop an efficient mechanism to capture the energy of the radiation of the sun as an energy source, to convert it into our required form of energy and to store it.

So far, human beings have only been able to devise three mechanisms for this purpose.

The Reflection or Parabola Mirror Method

A method right out of the ancient history textbook, the Reflection method is based on the idea of concentrating the rays of the sunlight on one point by the positioning of one or several mirrors, and the heat energy extracted out of the sunlight is used for the desired purpose. The similar method is also carried out through a parabola mirror, which is shaped like a dish antenna, and it is also used to concentrate the sunlight on a point to produce heat energy.

The Radiation Method

An ingenious yet simplistic method, that is the basis behind the concept of solar water heaters. It is carried out by placing black colored pipes, placed between two closely gripping layers of glass, and they are exposed to the sunlight. The sunlight heats the water up due to the radiation of the heat energy from the sunlight.

The Photovoltaic Method or the Solar Panels

It is one of the most popular methods today, and the only one being used for power generation.

It is based on the innovation of a solar cell, which is made up of treated silicon crystals, which are excited when exposed to the sunlight, and electrons are knocked out of their orbits as a result of the excitation and a hole is created in the crystal from which an electron had just escaped. It is filled by an electron from the crystal next to it, and since another hole is created while doing so, a steady flow of electrons, or an electric current is attained through this chain reaction of electrical charge. The electric current produced as a result can either be used immediately, or could be stored in a rechargeable battery for later use.

So Why are We Not Using Solar Energy?

So, despite of our knowledge about all the benefits of solar energy, why are we not using it even near to its total potential? Why there are only a few solar power plants around the world, the output of which is hardly 1% of the total power production of the world.

Firstly, the point about their cost of investment is raised to be a problem in using solar power, and even the reliability is considered as a hurdle, as solar energy cannot be utilized unless the sun is clearly able to send the sunlight on the surface, which is not possible if the sun is covered by clouds or during nights.

Another reason for that simply is the fact that we have not yet been able to devise a technology that efficiently converts the extent of solar energy received into a respective amount of electricity, as the solar cells can only convert 20% of the energy that falls on their surface into electrical energy. Such a level of production is not deemed sufficient for power production on a commercial basis.

However, that does not by any means imply that we should discard solar energy. The good news is that technological research is being carried out for an improvement in the efficiency of the photovoltaic system, and some considerable improvements are expected, both in cost and efficiency, and soon the technology will be acceptable to be adopted both for commercial and personal use.