Many times an appreciation for a technology is all that it takes for someone to warm up to it. So if you know how solar power works, you are better positioned to accept it as a potential solution for your home power needs. In the past decade, the photovoltaic cells have become one of the most popular products in the market. One of the big reasons for that is the boost the government has given the technology through incentives. These cells are not cheap and with many manufacturers in the market you need to become knowledgeable about these products. You need to be smart enough to pick the right products and solutions.
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.
Why are we talking about wavelengths for solar power? Well because the wavelength at which the solar equipment works is vital to judge how effective it would be. The sun’s light consists of many color frequencies. We can see some and we can’t see the others. Incidentally, the sun’s radiation contain more infra-red radiation than the visible light ones. So solar equipment that works under infra-red light absorbs more energy. Another concept is the light absorption. Anything that seems to have a color actually absorbs light from all other color wavelengths except its color – which it reflects back and hence we see it. Anything that looks black absorbs all the light, hence black solar equipment works better than colored ones.
Here is some mind boggling statistics for you – the total radiation from the sun that falls on the earth every day is 35000 times more than what we need for all our use. Imagine the gross waste of this abundant and clean energy source. In fact, if we can tap 6 kWh of sunlight from a 5 sq. meter area per day, we can power a house for that day. So the catch here is to capture maximum sunlight. The interaction between the photovoltaic cell components and the sunlight is vital in achieving this. There is an an interesting article on the site EzineArticles 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.
Want to find out more solar power facts then visit Richie Vee’s site on how to choose the best solar power kits for your needs.
