By: Todd Long
Submitted: 2010-06-22 14:15:39 | Word Count: 932
Renewable energy as of now seems to be more of a necessity rather than just another convenient option. The advantages of renewable energy are mentioned everywhere right from school curriculums to all the forms communicable mediums available. It has even acquired significant importance in the field of economics and politics. However when considering the present status quo, the question remains - why is it that renewable sources of energy like solar energy are yet to become mainstream?
The question becomes even more critical when we reflect on the fact that there are endless advantages if we switch to solar power. Then again solar power is not a recent technology i.e. it has been known to us for a while and we are indeed more familiar with it than many of the other forms of renewable energy sources.
During all these years we have depended on non renewable energy sources like fossil fuels to drive our progress. And when we analyze the facts, it’s certainly true that these fossil fuels have indeed helped us reach where we are right now. However they came at quite a price!
Due to the uncontrolled use of fossil fuels to drive our economies and technological aspirations we have bought upon ourselves a wide array of problems. One of the main problems is the issue of global warming. Considering its effects on Mother Nature we have been forced to look at renewable energy sources like solar energy. On a more ethical note – wars have been fought to gain control of oil resources, global economies and politics have also been affected by the rising and fluctuating prices of oil. Interestingly with the majority of the remaining fossil fuel resources beyond the reach of USA i.e. in the hands of other powerful nations like Russia – nobody wants to see another war. Then again in recent years many countries have used their fossil fuel resources as bargaining chips in the political arena and it hasn’t gone down very well with other powerful nations. To be more specific in the face of dwindling resources there is plenty of potential for conflict. Bottom line – It’s high time that we made renewable energy sources like solar energy more efficient and viable.
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The technology involved
In the most simplest of terms, solar energy can be defined as - the energy that is collected from the sun (Wikipedia). With regard to the manner in which solar energy is converted into electrical energy there are 2 main methods – the use of solar cells and by concentrating solar power.
Of these two methods the technique of using solar cells is more common, consequently it has been around for a while and is quite popular in many households. On the other hand the second technique i.e. the method of concentrating solar power has been a more recent technique and as of now – this method is most likely to be used for more commercial ventures.
A solar cell or photovoltaic cell is a device that converts light into electrical current using the photoelectric effect (Wikipedia). The basic principle here is that – an electric current is produced by certain materials when they release an electron. Electrons are released only when photons from the light rays strike these materials.
A more expansive or large scale use of photovoltaic cells include a technique known as concentrating photovoltaics. Special solar tracker devices are used here so that the focal point of sun’s rays remains on the cell. Hence this technique compensates for the movement of the sun across the sky during a typical day.
The second technique i.e. the concentrating of solar power, involves the use of lenses or mirrors along with tracking systems to focus sunlight from a large area into a small beam. The concentrated heat produced is used as the heat source in a conventional power plant. To be more specific the concentrated heat is used to heat a working fluid to produce steam. This steam is then used to turn the turbines and produce electricity. Recent developments have produced technologies that enable the fluid to store energy, however molten salt forms seem to offer the most potential when it comes to energy storage.
Issues with solar energy
In spite of the numerous advantages of solar energy, it does have quite a few disadvantages. Here are a few of them –
Viable solar energy generation techniques require a lot of land area to setup the wide array of mirrors and lenses. Inefficiency rates and complications can occur in areas that are prone to fluctuating weather conditions. The most common problem faced is – the lack of availability during night times and during other periods of low sun shine i.e. there can be interruptions and irregularities in the power supply. Quite a bit of energy is also lost when the electricity has to be converted from direct current to alternating current (Pakhare).
Photovoltaic cells as of now are relatively expensive. They are not exactly very efficient too, as they only convert about ten to twenty percent of the received light into electrical energy. Then again the reducing supply of essential elements like polysilicon is also an issue (West).
To bring down the costs and increase the efficiency of solar cells; innovative companies are developing solar cells based on CIGS i.e. these cells are composed of a thin film made of Copper, Indium, Gallium and Selenium. These cells are more flexible, durable and have the potential to compete with the prices of electricity generated from fossil fuels in the matter of a few years.
