Eco Green Facts

Archive for April, 2011

Very simply put, ‘Solar energy’ is energy that is derived from the sun. Our sun is an abundant source of energy, it gives off heat and light. The sun’s been revered by several cultures of the past and even by a few cultures still present today. The ancient Egyptians even worshiped the sun as a God.

 All said and done, it was not misplaced respect, the sun certainly is an abundant and limitless source of power, at least for several generations to come; the merits for using its solar energy are numerous.

 It’s free

Every morning with each dawn, the solar energy released by the sun filters through our atmosphere providing light and helping to radiate heat. This has been happening for millions of years yet it is only recently that we have begun to capitalize on this abundant source of almost infinite power.

In the past the Greeks and the Egyptians have been known to harness the power of the sun to heat whatever they wished to by concentrating its radiation. 

It’s non-polluting

 The energy from the sun is clean and free of any pollutants, unlike various sources of energy present today like petroleum or organic fuels which leave residues and  harmful gases when utilized to create energy.

 Extremely reliable

The sun has been burning for roughly four and a half billion years now and is likely to burn on for another four to five billion years to come. We take it for granted but this wonderful source of energy builds life on our planet and ensures a sustainable future for us all.

The saying “as sure as day” did not come about for nothing; assuming the sun is shining brightly, depending on which part of the globe you are you can harness the energy of the sun to either store it away or utilize its energy in a different way.

Limitless

There is no restriction on how much energy we can use from the sun. Apparently, the amount of energy that comes from the sun every few minutes, if successfully harnessed, can power the entire United States of America for a whole year. If we were only able to harness the immense energy of the sun we would be able to solve all the worlds’ energy problems.

Why

Ever wonder why no one thought about this earlier? How come if there’s so much energy just lying around, we simply cannot seem to efficiently harness it? How is it that so much of the sun energy seems to go totally unnoticed and is ultimately wasted?

Well one of the reasons that this wonderful power reserve is generally wasted is the fact that the sunlight that we actually receive is so thinly dissipated across the earth. For us to be able to actually harness the power of the sun we have to be able to manipulate, focus and store the sun’s energy. While this may seem simple it is easier said than done. So far we have only managed to develop three partially successful means of collecting solar energy.

 The Reflection Method – Mirrors / Parabola

The reflection method is based on the concentration of the sun’s rays through a single or a set of mirrors onto one point and then utilizing the concentrated heat energy that is produced for our needs. A parabolic mirror, much like a dish antenna, can be used to capture the sun’s rays and focus them on a single point. 

 The radiation method

 This is the principle behind the solar water heaters. Painted black pipes sandwiched between two layers of glass, have water inside them that is heated thanks to the rays of the sun.

Solar panels

 A more recent invention, the ‘solar cell’, is composed of treated silicon crystals, which when hit by the rays of the sun knock electrons out of their orbits and thereby create a void that needs to be filled by electrons from the other silicon crystals, this creates an imbalance of electrons and hence a flow of current which can be either immediately utilized or else stored away in a rechargeable battery.

What’s stopping us?

 Despite the apparent benefits of using solar power it is most unfortunate that there are very few solar power plants around the world. Sadly, with today’s level of technology, cost and reliability are two major factors that are still hurdles in the way of mass usage of solar energy. 

Technological limitations dictate that the most efficient solar cells created today are still not capable of generating enough power to be commercially viable without occupying huge surface areas. Furthermore, reliance exclusively on solar cells is not yet practical,  for if there were to be a cloudy day it could reduce the amount of electricity generated and that would be disastrous for those people completely reliant on that energy.

On the bright side, constant innovation and research on solar energy is resulting in much more efficient solar cells that are a fraction of the size of existing cells and churn out much more power. For now they are still expensive, but not far away is the day when they will be affordable and available to the common man.