Solar energy: Advantages and limitations
Posted by Solar energy guru | Filed under Solar energy facts
Solar energy is power derived from the rays of the sun. It is considered to be one, if not the most, environmentally friendly source of energy that can be used on earth. Studies up to this point in time, indeed, show that generating power or heat using solar energy does not produce the same environmental threats that come with the utilization of traditional sources of energy particularly fossil fuel. In the interest of optimum efficiency and utilization of energy generators, however, it is always important to consider both the upside and the downside of any potential sources of energy available to us. Power production on earth involves not only the laws of physics but of economics as well. The difference between favorable and unfavorable ratio of cost to effect in economics has much power by itself to dim or actually black out any power production method regardless how environmental-friendly that method is. With this in mind let us look at the favorable points and limitations of solar energy.
The prime mover of all activities in this world, in the industries and in households, is the power that is produced by electricity or generated heat. Electricity can produce the power to move things and light up darkness. It can also generate heat. Heat can also produce the power to move things, generate electricity and also light up darkness. Since the discovery and development of the steam engine, internal combustion, servomechanisms and semi-conductors, the need to generate electricity and usable heat has become the primary concern of man, which leads to the exploitation of the heat and electricity generating potentials of combustible materials, particularly fossil fuels. The energy that can be released in the burning of fossil fuels is called fossil energy. Other materials that can produce heat and electricity are also exploited. For example, plutonium and uranium, which are radioactive materials. The energy that can be released by breaking down nuclear materials is called nuclear energy. Later it was discovered that the rays of the sun can also be made to generate heat to the point of temperature that can render it useful for different purposes, and when caught by special photo-sensitive cells the rays can even directly generate electricity. The energy from the rays of the sun that can be converted to usable heat and electricity is referred to as solar energy.
Solar energy has been used in minute scale for heating houses, cooking some food and generating a certain amount of electricity for household or personal use. In industrial settings, solar energy has been successfully used in desalinating seawater to produce fresh water for human consumption, and conversely, in producing sea salt in desalination plants. There are houses, boats and industrial or scientific facilities that either partly or wholly rely on solar energy to power their electrical appliances or equipment. Solar energy is utilized either by amplifying the heat of the sun’s rays through a particular “ray collecting” system, such as used in heating water or cooking certain foods, or by catching the rays of the sun using special photo-sensitive cells of semi-conductors arranged in panels, called solar panels, that can be positioned for optimum exposure. When the rays of the sun hit these photosensitive cells they cause the electrons in them to move and create a usable current of electricity.
Many favorable points can be said about the use of solar energy. One is that it can be used to produce electricity or heat without a by-product or residue of dirt as it requires no burning of any combustible material. Another favorable point is the obvious fact that it poses no danger of radioactive contamination to anyone as there is no breaking down of any radioactive material. It can generate electricity or usable heat without noise. The source of solar energy is inexhaustible as long as the sun is there. It is free and can be used by anyone in abundance.
Homeowners whose houses are heated, even just partially, by solar energy claim to large amount of savings, as heating houses with gas or power plant generated electricity that are distributed commercially costs so much. In remote areas that are not adequately supplied or cannot be reached by electricity that is distributed through grids and power lines, solar energy can meet the basic electrical power needs of a household or work facility. It can be used to light up lamps, cook food, power refrigeration or air conditioning equipment and desalinate or purify water. Solar panels have become standard equipment in pleasure boats, passenger ships and large ocean tankers. They are being relied upon to supply electricity that power communication and navigation equipment.
The supply of solar energy is almost limitless in geographic areas where the sun shines at more hours in most part of the year. Ironically, however, it is this dependence of solar energy on the amount of the sun’s rays that it can get that gives it its limitations. There are several factors that limit the entry of the sun’s rays into the earth’s atmosphere. One of course is the nocturnal and diurnal cycle, which is the cycle of night and day. Another is the atmospheric shield itself that “dilutes” the intensity of the sun’s rays as it penetrates this shield towards the surface of the earth. Still another is the cloud covering over areas on earth that further lessens the intensity of the incoming rays. The degree of intensity of the sun’s rays dictates on how efficient ray collectors can amplify the heat received from the sun and on how large the photo-sensitive solar panels should be and how many will be needed to get the electrical power that is desired. The greater the dilution of the intensity of the rays of the sun the larger the collectors and the solar panels should be and the more number of panels will be required.
Sun ray collectors and photosensitive solar panels, up to the present, are still very expensive equipment. In locations where, nighttime is longer than daytime, the use of solar energy may not necessarily cut the cost of energy, and any savings from the cost of traditional source of power may not actually offset the cost of investment made on the solar energy equipment. There are places where daytime is longer than nighttime in most part of the year, but the weather condition is such that clouds cover most part of the sky all day. This is true in many tropical countries where the storm season takes almost half of the year. Ironically, also, in many countries where the sun is uncovered most of the day and year, like in the sub-Saharan parts of Africa, the economic condition of the people is such that the cost of sun ray collectors and solar panels for household or industrial use is just way beyond their reach.
Researchers and developers who are focused on the technology that seek to harness the power of the sun to generate electricity and usable heat here on earth continue to look for and employ means of making solar energy a source of power that can be used in large scale and distributed to every one as much as possible. Time may come soon when the favorable points creditable to solar energy will greatly outnumber its limitations. For the time being, getting as much information that is available about it would be worth the investment of time and would surely optimize the benefits it can give once the decision to invest on it is made.