Veritech Energy Technology

It may be hard to believe, but solar energy is the oldest form of energy ever used by humans-it pre-dates even our harnessing the energy of fire. Solar energy is used mostly for generating electricity and generating heat. Although the technologies inherent in these two uses are vastly different, the physics are amazingly the same. We capture sunlight and convert it into heat or electricity. How do we capture sunlight, though, and how do we convert it into power? And what problems must we solve and how do we do so efficiently? Read below for answers:

Understanding Light

We are continually surrounded by light, most of which we can’t even see. What we know as “light” is really a form of energy comprised of individual units known as photons. These photons have wavelengths and these wavelengths determine a light’s color. Only a small spectrum of light is visible to the human eye. The photons’ wavelength frequency is the determining factor in its energy. For example, a photon with a high wavelength will have more energy than a photon with a lower wavelength. The best analogy to illustrate this concept is to imagine two snakes, one longer than the other, both crossing a hot highway. The longer snake can cross the road with longer strides due to its longer length. It has, essentially, a longer wavelength. However, in order for the shorter snake to move as quickly as the longer snake, it will need to “wiggle faster” because it is shorter. It can keep up, but it will have to exert a great deal more energy than the longer snake in order to do so.

Remember that only a small portion of the light spectrum is visible to the human eye. At the low end of the visible light spectrum is blue light, which has a great deal of energy (high frequency). At the opposite end of the visible light spectrum is red with its lower energy (low frequency). Past the red, is an invisible portion of the light spectrum known as infrared, which is essentially radiated heat. A light’s wavelength is important because scientists who are “light collectors” will selectively choose wavelengths best suited to convert into energy. A less able scientist might use infrared wavelengths, for example. A home’s water heater powered by solar energy efficiently uses more of the color spectrum than, say, PV cells. However, recent improvements in PV cells use more of the color spectrum than PV cells of the past. These improvements allow for greater efficiency.

A more passive but still effective use of solar energy can be found in windows that are designed to filter out infrared and ultraviolet lights. These new windows are important to homeowners for a variety of reasons. First, infrared sun rays create a great deal of heat in a home; additionally, ultraviolet rays damage a home’s carpets and other fabrics such as drapes. Because neither ultraviolet nor infrared sunlight is visible to the human eye, the new windows do not change the naked eye’s view of the outside world.

To give you an idea about how the sun’s rays are dispersed once they hit earth, consider the following statistics:

· 0.02% is absorbed by plants for photosynthesis
· 0.2% creates wind energy in out atmosphere (wind energy is a kind of kinetic energy)
· 22% is used to evaporate water, which in turn creates rain
· 35% reflects back into space and away from earth
· 43% is absorbed as ground-based and atmospheric-based heat radiation