The prime source of Ancient Energy- The Sun's Energy is the goal of modern human race. We dream of tapping into this near unlimited source of Energy in an efficient way. The idea of utilising photon energy came with the Birth of Quantum Mechanics. The concept of Photoelectric effect sowed the seeds of photo cells and other photovoltaic devices. And soon the revolution of photovoltaic cells began as a major promising step to eradicate fossil fuels and start an era of Green Energy.
Before going into applications it is better to have a proper grasp of the theory behind.
Photo Voltaic cells or Solar Panel that we have developed in the recent future to tackle the need for Green Energy, is based on the concept of absorbing Photon Energy coming from the mother source-Sun. It convert photon Energy into Electrical Energy using a phenomenon called the Photoelectric Effect. As per this Sunlight is used to give the loosely bound electron Kinetic Energy and drive a current. This current is DC by nature and can be used to run Electrical appliances or stored in a battery in the form of Chemical Energy. At present most commercially used solar panels are made using semiconductors( Doped to increase efficiency).
The Commercial use of Solar panels.
With the advancement of Solar Panel tech. and requirement for green energy (Due to rising threat of Global Warming ) Countries all over the world are trying to promote the use of Solar Panels. In various countries, various solar power based devices have been developed. Some commercial uses are :
- Solar Pressure Cooker
- Solar Street lamps- Being wildly implemented in India
- Solar Powered e-Devices like Calculator
- Solar Chargeable Lamps
and many more...
The new challenges with Solar panels are its cost effectiveness, efficiency and power output. Due to this, its uses in building solar powered vehicles and as power stations are limited. The average efficiency of light capture is 7-10% and so it needs a large amount of time and a huge effective surface area.
The Governments of various countries tried to overcome this effect by building solar farms. Solar farms are large setups of solar panels in inhabitable areas like deserts to store Green Energy in Industrial Scales. Such constructions also protect the land from the sun's heat and help to cool down desert lands. In some places Solar farms have been setup in the sea so that land is not wasted. Many deserts like the Thar, Sahara and the Australian desert are being converted into Solar farms. China has a floating solar farm in the China sea.
Solar Projects of India
India is investing heavily in renewable resources but has the lowest per capital cost per MW globally to install solar power plants. The country's solar installed capacity reached 37.627 GW as of 31 March 2020. The Indian government had an initial target of 20 GW capacity for 2022, which was achieved four years ahead of schedule. In 2015 the target was raised to 100 GW of solar capacity by 2022, with an estimated investment of 100 billion USD. A large number of solar street bulbs have been installed in the past few years. This new method is helping in making electricity available in remote parts of India.In a decade ending on 31 March 2020, India expanded its installed solar power capacity by 233 times from 161 MW to 37,627 MW.India has established nearly 42 solar parks to make land available to the promoters of solar plants.
India's Scope in near future
The main problem with solar power project is the availability of cheap land for setting up solar parks. A modern way to deal with this is to build floating solar panels (Already implemented in China) over lakes, canals and other large water bodies. Due to better cooling effect, the Energy production efficiency is enhanced and due to large availability of water cleaning is not an issue ( as is in the case of solar plants of the deserts). Recently the price of such floating panels have steeply decreased making these feasible.
In 2019, Indian Railways announced the plan to install 4 GW capacity along its tracks. Highways and railways may also avoid the cost of land near load centers, minimising transmission-line cost by having solar plants about 10 meters above the roads and rail tracks.
The best suited architecture for India would be the roof-top power generation system connected via local grid. The cost of mono PERC modules and battery storage have also reduced making these feasible.
statistics suggest that India would be able to make renewable resources the backbone of its economy by 2030, thus reducing the carbon footprint without compromising its economy. Study suggest that up-to 100GW of Energy would be produced using various methods.
Modern advancements and Techniques being developed :-
The need for renewable energy source have convinced scientists to work on better and more efficient ways of capturing natures energy. Most of the solar energy coming from the sun is absorbed by the atmosphere. On average 1388 Watt / meter square energy reaches the upper atmosphere of the Earth, out of which about 1000 Watt/ meter square reaches Earth's Surface. The commercially used Solar panels at present have an efficiency of 10-15% at most. Sacrificing cost it goes up to about 42%.
At present some new techniques have come up to increase efficiency. Some places have Single/Dual axis tracker panels that shift in such a way that the sun rays are always perpendicular to the surface. Recently, research have started in building solar panels in space since the energy coming from the sun is not screened by the atmosphere, but this idea is still far fetched. At present the satellites are powered mostly by solar energy since they have low energy requirements.
Solar Energy is also being captured in form of heat. Water is heated using solar water heater or the more advanced vacuum tube solar water heater especially in cold countries, where this water can be stored with minimal radiation at a warm temperature for months.
Another important factor that can be tweaked to increase electricity production through solar panels is the material used for capturing sunlight. Mono crystalline, Poly Crystalline and Thin film solar panels are some new ones that are coming to market.
Mono crystalline- These are manufactured from purest form of silicon. These crystals are produced through a complex Mechanism to produce a rod, which is then cut into wafers and used in solar cells. These are fairly costly but gives an astounding efficiency of 22-27 %.
Poly Crystalline- These are slightly less efficient than the above, mainly because of their method of preparation. The silicon is not grown as a single cell but a block of crystals.These blocks are then cut into wafers to produce individual solar cells. These have an efficiency of about 15-22 %.
Thin film- These are made by covering a substrate of glass plastic or metal with one or more thin-layers of photo voltaic material. These are flexible, low, weight and cheaper but lasts less than the other two. These have efficiency ranging between 15-22 %.
Solar technologies can be improved immensely by using nano technology and nano doping methods. The world need large investment in solar power generation projects and we need a breakthrough in Solar Tech. The future of mankind would be secured only through implementation of green energy techniques and environment friendly sustainable development.
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