22-05-2013, 04:35 PM
TECHNICAL SEMINOR Solar Energy The Renewable Energy For The Future
TECHNICAL SEMINOR.doc (Size: 1.98 MB / Downloads: 29)
Abstract:
The oil shocks of 1970s led to spiraling crude oil prices in the world market which prompted planners to view energy security as an issue of national strategic importance. Energy security has an important bearing on achieving national economic development goals and improving the quality of life of the people. World’s dependence on crude oil will continue for most part of the
21st century but the continued dependence on crude oil is loaded against it with inherent price volatility linked to finite global reserves. In addition, global warming, caused largely by greenhouse gas emissions from fossil fuel energy generating systems, is also a major concern. So, there is a need to develop alternate fuels like non-conventional sources, considering the aforesaid two concerns.
This paper describes about the solar energy, one of the non-conventional sources and different ways of using it to convert to electric energy.
Introduction:
As the power demand is going on increasing day-by-day, it is responsible for our engineers to make it available
as per the demand. Many of the power generating plant are using non- renewable sources as their primary source. But these may become extinct at any time and before facing the situation we have to choose an alternative to avoid the power crisis. One of the best alternatives is choosing Non-conventional sources like Solar energy, Wind Energy, Tidal energy, Bio-mass energy etc as the primary sources for power generation in power stations. The power from these sources is several times greater than the one, which we are using at the present. Out of these energy sources, the best one which suits for our country is the Solar energy.
Sun:
As far back as 5,000 years ago, people "worshipped" the sun. Ra, the sun-god, who was considered the first king of Egypt. In Mesopotamia, the sun-
god Shamash was a major deity and was equated with justice. In Greece there were two sun deities, Apollo and Helios. The influence of the sun also appears in other religions - Zoroastrianism, Mithraism, Roman religion, Hinduism, Buddhism, the Druids of England, the Aztecs of Mexico, the Incas of Peru, and many Native American tribes.
What is solar energy?
Solar energy can be converted into other forms of energy, such as heat and electricity. In the 1830s, the British astronomer John Herschel used a solar thermal collector box (a device that absorbs sunlight to collect heat) to cook food during an expedition to Africa. Today, people use the sun's energy for lots of things.
How is solar energy collected?
Solar energy can be used to heat a fluid such as water in solar collector panels. Simple types use flat collector panels mounted on a south-facing roof or wall, each with transparent cover to admit sunlight. Water circulates through channels or pipes inside each panel. The inside is usually painted black, because black surfaces readily absorb heat. The water is heated, and then the hot water is pumped to a heat exchanger that extracts the heat for use within the house.
Solar energy can also be used to generate electricity in photovoltaic (PV) cells. A PV cell may power your calculator. Photovoltaic cells are made of semiconductors, similar to those used to make computer chips.
Basic structure:
Large parabolic collectors are employed for collecting solar energy, which is used to heat the fluid generally water which is stored in the storage tank. This heat energy is let to the boiler with a feedback, which is converted to high-pressure steam energy. This steam energy is sent to the turbine chamber with high speed leading to the rotation of prime- mover of the turbine. As turbine is internally coupled with the alternator, the incoming mechanical energy to
the turbine is converted to electrical energy by the alternator. Steam is condensed in the condenser and feed water returns to the boiler for re-use. The heat of the cooling water of the condenser may be utilized for some other purposes.
Conclusion:
In the capital city of India, Delhi, citizens can face hours without electricity, but they are the lucky ones. In some parts of India it can be days. The basic weakness of the electric supply industry is non- viability of tariff. In 2001-02, the cost of supply was Rs.3.50 a unit while the realization was only Rs.2.40. Free or highly subsidized supply for agriculture and subsidies to domestic consumers have resulted in uneconomic charges for industrial consumers. This policy has driven many industries to depend more and more on self-generation. A second weakness of the Indian situation is under investment in transmission and distribution relative to generation. This is due to the lack of proper return in the investment of the power stations. This leads to the increase in price/unit and making the cost unreasonable for the common man.