How Does Solar Power Work For You?
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by: RichieVee | Total views: 13 | Word Count: 857
Solar power is a new concept and there will always be apprehensions before adopting it. However, if you can understand the basics of how does solar power work, you'll make an educated decision on which solution works to solar power your house. The building block of solar energy is the photo voltaic cell or PV. There has been a lot of research and development around PV over the last ten odd years, primarily due to a push from the government. Today you have many products in the market and picking one can be really tough. This is where understanding about solar energy is useful.
The sun as we see it today, is one of the largest nuclear reactors known to man. The reactions within the sun continue to produce energy in the form of light. Light consists of photons which are characterised by two factors: wavelength and frequency. The wavelength of a photon is the distance between two photons in the same phase of motion and the frequency is the rate at which the photons change their phases.
The concept of wavelength is important in understanding solar energy products because the sun does not radiate uniformly at all wavelengths. Unless you can appreciate this concept, you will have a tough time figuring out which solar equipment will convert maximum solar energy. Typically the sun radiates more energy in the infra-red range of wavelengths than the visible range. Here you must also understand the idea of colors of various objects. The sun's light is white light, which means it has all the colors, but when it hits a blue object, you can see the blue color. This is because that object absorbs all the colors and reflects back blue. Logically, anything that seems black in color is absorbing all the light and reflecting none.
The total energy radiated by the sun can satisfy our growing energy demands many times over. In fact, if we can generate 6 kWh of power from 5 square meters of PV cells, that energy is sufficient to power our whole house with all the appliances for that day. Just imagine the sheer quantity of energy we have been neglecting for centuries. Tapping the solar energy is basically, facilitating a photonic reaction between the sunlight and the PV to convert the light energy into electric energy that can be used to power our home. Of course, if you do not have the optimum solar energy absorption you will end up with an inefficient system. Check out this interesting article about portable solar power. Go there for more info.
At this point it is also interesting to understand the idea of passing radiation. We have seen how certain objects can absorb light and some that can reflect certain wavelengths. Some materials like the glass can actually let the radiation pass through them. These materials are used as solar collectors, because they pass the light radiations and insulate the unit from the heat protecting the PVs in the assembly. Mediums that do not absorb or reflect the entire light, but let some pass through them are called filters. The filter coating that we cover our home windows with is a good example. Similarly, we have several sunglasses with UV filters - these glasses do not allow UV rays to pass, but let other light wavelengths to pass. Filters are vital in the glazing for solar equipment. Glazing is the term used for materials that cover the solar equipment and let the light pass through. With the right filters the most energetic light rays can be passed while the rest are filtered out for very efficient performance. We know that the infra-red range is the best to tap solar energy so the glazing needs to filter out the rest of the light.
So there are three characteristics of any material: filtering, absorbing and reflecting. Even the windows made from glass that are supposed to pass white light do not do so completely; they actually pass just 85% of the light and rest is lost or filtered. Another common filter is our atmosphere. During dawn and dusk the sun's rays travel further in the atmosphere and hence they are not that strong or bright. At noon, with sun directly overhead, the light travels perpendicular to the atmosphere so it traverses shorter distances this means it gets filtered less and hence is more powerful.
The same idea holds true for summers and winters as well. During summer more of the sun's light reaches the earth surface as compared to winters. As a result, more sunlight is reflected and absorbed in summer. Absorption of photons releases energy in the form of heat and this heat warms the air. This why summers are hotter and winters are cooler. In fact, heat is nothing but a function of motion. When a surface absorbs energy its molecules start to vibrate and this generates heat. Thus when solar energy strikes the surface it causes the molecules to vibrate releasing heat energy. These are some of the basic aspects of solar energy that you must be aware of. Understanding these concepts will aid you in understanding how solar power equipment works.
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