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ABSTRACT ENERGY is key input to drive and improve the life cycle. The primary source of energy is fossil fuel, however the finiteness of fossil fuel reserves and large scale environmental degradation caused by widespread use , air pollution suggests that harnessing of non conventional energy sources is important for global energy supplies. Energy is subject to the law of conservation of energy. According to this law, energy can neither be created (produced) nor destroyed by itself. It can only be transformed. INTRODUCTION Energy sources are classified in to two groups.-conventional energy and non conventional energy. conventional energy is energy which comes from the natural sources such as sunlight, wind, rain, tides, and geothermal heat. About 16% of the global energy comes from the renewable s. a non conventional resource is a natural resource which cannot be produced, grown, regenerated or used on a scale which can sustain its consumption rate. Non-renewable sources are fossil fuels(such as coal, petroleum, natural gas), types of nuclear power and certain aquifiers. NON-CONVENTIONAL RESOURCES India has a vast potential of renewable energy resources and a number of technologies have been developed to harnesss them. In india the department of non conventional energy sources(dnes) was set up in 1982 and upgraded to a full fledged ministry MNES which looks after the development of non conventional energy resources. Some of the non conventional energy sources are 1. Solar energy 2. Wind energy 3. Tidal energy 4. Hydel energy 5. Geothermal energy 6. Biomass SOLAR ENERGY: Since most of the renewable enrgy is ultimately solar energy that is directly collected from the sunlight. Energy is released by the sun as electromagnetic waves. This energy reaching the earths atmosphere consists of about 8%UV radiation, 46% visible lightand 46% infrared radiations. It is believed that with just 0.1 % of the 75000 trillion KWH of solar energy that reaches earth, the planets energy requirements can be fulfilled. Solar energy can be utilized in three ways : (i) converting to thermal energy, (ii) converting in to electricity; and (iii) photosynthesis (i)Converting in to thermal energy: Thermal energy from sun can be collected by using a solar collector. A large number of solar thermal energy applications particularly those where low- grade thermal energy is required, have already become commercial. these include solar cookers, solar air heating, crop drying, refrigeration, water pumping, solar water heating systems ,water desalination. Solar water heating systems have a vast potential to save electricity in domestic and commercial sectors and furnace oil in industrial sector which otherwise are being used for hot water supply. A proposal for setting up a 35MW solar thermal power plant at maithania village in rajasthan based on focusing collectors has been under the consideration of the ministry. Solar energy centre under the MNES is the nodal agency for r&d effort. Main activities of the centre include solar heating research,system design and engineering, solar thermal power generation, solar passive architechture and green house technology. (ii) Converting in to electricity: Electricity is directly generated from the solar energy. It works on the principile of the photoelectric effect, which is: when light falls on the certain metals like silicon, the electrons get excited and escape from the metals; the electron flow thus set up constitutes the electric current. The basic unit of solar photovoltaic system(spv) is a solar cell which is a wafer of electron emmitting metal. solar electrification in villages also began. Salijipally in Andhra Pradesh became the country’s first village to b e electrified using the SPV systems. At present SPV systems in india are being used for powering a variety of low power applications in rural,remote and un-electrified areas for lighting and water pumping, power for railway signaling rural telecommunication systems, water purifying for drinking and irrigation,TV transmission. This way of using the solar energy is attractive considering the favorable solar condition and large energy requirements of electricity for decentralized applications. The easy installation and maintenance , absence of noise and pollution and long life make SPV systems favorable for use in remote and isolated areas , forest, hilly and desert region. The major drawback of SPV systems is its high initial costs, the most expensive input being the silicon wafer which is partly imported. (iii)PHOTOSYNTHESIS: Photosynthesis is a process of chemical conversion of carbon dioxide and water in to carbohydrates in presence of sunlight and chlorophyll by the plants is one of the nature’s most efficient method of conversion of solar energy in to storable form. It has been proved both in algae and in higher plants that under optimal conditions and over short period of time and at relatively low intensity light up to 30 percent of the light absorbed is transformed in to chemical energy. WIND ENERGY: Wind is emerging as one of the most potential source of alternate energy that wil be helpful to a great extent in bridging the gap between the energy demand and supply.The origin for wind energy is sun. when sun rays fall on earth , uts surface gets heated up and as a consequence unevenly winds are formed. Kinetic energy in the wind can be used to run wind turbines but the output power depends on the wind speed. Turbines generally require a wind in nthe range of 55 m/sec. wind power is one of the most cost competitive renewable today and this has been the most rapidly growing means of electricity generation at the turn of 21st century and provides a complement to large scale base –load power station. A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or pumping water, the device is called a windmill or wind pump. Wind turbines can rotate about either a horizontal or a vertical axis, the former being both older and more common. Horizontal-axis wind turbines (HAWT) have the main rotor shaft and electrical generator at the top of a tower, and must be pointed into the wind. Small turbines are pointed by a simple wind vane, while large turbines generally use a wind sensor coupled with a servo motor. Vertical-axis wind turbines (or VAWTs) have the main rotor shaft arranged vertically. Key advantages of this arrangement are that the turbine does not need to be pointed into the wind to be effective. This is an advantage on sites where the wind direction is highly variable, for example when integrated into buildings. The key disadvantages include the low rotational speed with the consequential higher torque and hence higher cost of the drive train, the inherently lower power coefficient. The problems associated with Utilizing wind energy are that: (i) The energy is available in dilute form, because of this conversion machines have to be necessarily large. (ii) The availability of the energy varies considerably over a day and with the seasons. For this reason some Means of storage have to be devised if a continuous supply of power is required. A wind mill converts the kinetic energy of moving air into mechanical energy that can be either used directly to run the machine or to run the generator to Produce electricity. The total wind energy potential in india is estimated at 20000 MW. A total capacity of 732MW has been installed by 1995-96.wind energy is free renewable resource , so no matter how much is used today, there will still be the same suppl in the near future. Wind energy is also a source of clean, non-pollution electricity. The technology requires a higher intial investment than fossil fueled generators. Although wind power plants have a relatively little impact on the environment compared to fosil fuel poewer plants, there is some concern over the noise produced by the rotor blades, aesthetic impacts . the major challenge using wind as a source of power is that it is intermittent and does not always blow when electricity is needed. Wind cannot be stored and not all winds can be harnessed to meet the timing of electricity demands. TIDAL ENERGY: Gravitational forces between the earth moon and the sun cause the rhythmic rising and lowering of ocean waters around the world that results in tide waves.the magnitude of tides changes during each lunar month. The highest tides , called spring tides ,occur when the eath, moon and sun are positioned close to a straight line. The lowest tides, called neap tides occur when the earth, moon and sun are at right angles to each other. Extraction of tidal energy can be done in two ways. (i)Traditional approach. (ii) Non traditional approach. Traditional approach: All existing tidal power plants use the same design that is accepted for construction of conventional river hydropower stations. The three principal structural and mechanical elements of this design are: a water dam across the Sow, which creates an artificial water basin and builds up a water head for operation of hydraulic turbines; a number of turbines coupled with electric generators installed at the lowest point of the dam; and hydraulic gates in the dam to control the water Sow in and out of the water basin behind the dam. Sluice locks are also used for navigation when necessary. The turbines convert the potential energy of the water mass accumulated on either side of the dam into electric energy during the tide. The tidal power plant can be designed for operation either by double or single action. Double action means that the turbines work in both water flows, i.e. during the tide when the water flows through the turbines, filling the basin, and then, during the ebb, when the water flows back into the ocean draining the basin. In single action systems, the turbines work only during the ebb cycle. In this case, the water gates are kept open during the tide, allowing the water to fill the basin. Then the gates close, developing the water head, and turbines start operating in the water flow from the basin back into the ocean during the ebb. Advantages of the double-action method are that it closely models the natural phenomenon of the tide, has least effect on the environment and, in some cases, has higher power efficiency. However, this method requires more complicated and expensive reversible turbines and electrical equipment. The single action method is simpler, and requires less expensive turbines. The negative aspects of the single action method are its greater potential for harm to the environment by developing a higher water head and causing accumulation of sediments in the basin. Non- traditional approach: This traditional river scheme has a poor ecological reputation because the dams block fish migration, destroying their population, and damage the environment by flooding and swamping adjacent lands. Flooding is not an issue for tidal power stations because the water level in the basin cannot be higher than the natural tide. However, blocking migration of fish and other ocean inhabitants by dams may represent a serious environmental problem These environmental and economic factors have forced scientists and engineers to look for a new approach to exploitation of tidal energy that does not require massive ocean dams and the creation of high water heads. The key component of such an approach is using new unconventional turbines, which can efficiently extract the kinetic energy from a free unconstrained tidal current without any dams. One such turbine called the Helical turbine. Due to its axial symmetry, the turbine always develops unidirectional rotation, even in reversible tidal currents. This is a very important advantage, which simplifies design and allows exploitation of the double-action tidal power plants. UTILIZING ELECTRIC ENERGY FROM TIDAL POWER PLANTS: Tides are cyclical by their nature, and the corresponding power output of a tidal power plant does not always coincide with the peak of human activity. In countries with a well-developed power industry, tidal power plants can be a part of the general power distribution system. However, power from a tidal plant would then have to be transmitted a long distance because locations of high tides are usually far away from industrial and urban centers. An attractive future option is to utilize the tidal power in situ for year round production of hydrogen fuel by electrolysis of the water. The hydrogen, liquefied or stored by another method, can be transported anywhere to be used either as a fuel instead of oil or gasoline or in various fuel cell energy systems. Fuel cells convert hydrogen energy directly into electricity without combustion or moving parts, which is then used, for instance, in electric cars. Production of hydrogen by water electrolysis using tidal energy is one of the best ways to develop clean hydrogen fuel by a clean method. Thus, tidal energy can be used in the future to help develop a new era of clean industries, for example, to clean up the automotive industry, as well as other energy-consuming areas of human activity. HYDEL POWER: Energy in water can be harnessed and used in the form of motive energy or temperature difference. Since water is about a thousand times heavier than air is, even a slow flowing stream of water can yield great amounts of energy . hydro electricity is electricity referring to electricity generated by hydropower, the production of electrical power through the use of gravitational force of falling or flowing water . it is the most widely used form of renewable energy. GENERATING METHODS: CONVENTIONAL ( DAMS): Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. The power extracted from the water depends on the volume and on the difference in height between the source and the water’s outflow. This height difference is called the HEAD. The amount of potential energy in water is propotional to head. A large pipe delivers water to the turbine. PUMPED STORAGE: This method produces electricity to supply high peak demands by moving water betweenreservoirs at different elevations. At times of low electrical demand, excess generation capacity is used to pump water in to the higher reservoir. When there is higher demand , water is released back in to lower reservoir through a turbine. Pumped storage schemes currently provide the most commercially important means of large scale grid energy storage and improve the daily capacity factor of the generation system. RUN OF THE RIVER: Run of the river hydro electric stations are those with small or no reservoir capacity. So that the water coming from upstream must be used for generation at that moment , or must be allowed to bypass the dam. The major advantage of the hydroelectricity is the elimination of the cost of fuel. Operating labour cost is very low. Hydroelectric plants have long economic lives with some plants still in service after 50-100 yrs. Since hydroelectric power plants do not burn fossil fuels, they do not directly produce carbon dioxide. while some of carbon dioxide is produced during manufacture and construction of this project. Hydroelectric systems can be disruptive to surrounding aquatic ecosystems both upstreamand downstream of the plant site.generation of hydroelectric power changes the downstream river environment. Siltation can fill a reservoir and reduce its capacity to control floods along with causing additional horizontal pressure on the upstream portion of the dam. Lower river flows because of drought, climate change or upstream dams and diversions will reduce the amount of live storage in a reservoir therefore reducing the amount of water that can be used for hydroelectricity. The result of diminished river flow can be power shortages in areas that depend heavily on hydroelectric power. Lower positive impacts are found in the tropical regions, as it has been noted that the reservoirs of power plants in tropical regions may produce substantial amounts of methane. This is due to plant material in flooded areas decaying in an anaerobic environment, and forming methane, a potent greenhouse gas. Another disadvantage of hydroelectric dams is the need to relocate the people living where the reservoirs are planned. In many cases, no amount of compensation can replace ancestral and cultural attachments to places that have spiritual value to the displaced population. Additionally, historically and culturally important sites can be flooded and lost. GEOTHERMAL ENERGY: Geothermal energy is the thermal energy generated and stored in earth. Thermal energy is the energy that determines temperature of the matter. Earth's geothermal energy originates from the original formation of the planet (20%) and from radioactive decay of minerals (80%). The geothermal gradient, which is the difference in temperature between the core of the planet and its surface, drives a continuous conduction of thermal energy in the form of heat from the core to the surface. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock. Extremely high temperature and pressure cause some rock to melt, which is commonly known as magma. Magma convects upward since it is lighter than the solid rock. This magma then heats rock and water in the crust. A geothermal heat pump system consists of a heat pump, an air delivery system (ductwork), and a heat exchanger-a system of pipes buried in the shallow ground near the building. In the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system. In the summer, the process is reversed, and the heat pump moves heat from the indoor air into the heat exchanger. The heat removed from the indoor air during the summer can also be used to provide a free source of hot water. Hot dry rock resources occur at depths of 3 to 5 miles everywhere beneath the Earth's surface and at lesser depths in certain areas. Access to these resources involves injecting cold water down one well, circulating it through hot fractured rock, and drawing off the heated water from another well. Geothermal power is cost effective, reliable, sustainable, and environmentally friendly. . Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are much lower per energy unit than those of fossil fuels. As a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels. Geothermal power requires no fuel (except for pumps), and is therefore immune to fuel cost fluctuations, but capital costs are significant. Drilling accounts for over half the costs, and exploration of deep resources entails significant risks. Fluids drawn from the deep earth carry a mixture of gases, notably carbon dioxide (CO2), hydrogen sulfide (H2S), methane (CH4) and ammonia (NH3). These pollutants contribute to global warming, acid rain, and noxious smells if released. In addition to dissolved gases, hot water from geothermal sources may hold in solution trace amounts of toxic chemicals such as mercury, arsenic, boron, and antimony.[40] These chemicals precipitate as the water cools, and can cause environmental damage if released. Direct geothermal heating systems contain pumps and compressors, which may consume energy from a polluting source. Geothermal Plant construction can adversely affect land stability. Geothermal has minimal land and freshwater requirements. Biomass: Biomass is carbon, hydrogen and oxygen based. Biomass energy is derived from five distinct energy sources: garbage, wood, waste, landfill gases, and alcohol fuels. Wood energy is derived both from direct use of harvested wood as a fuel and from wood waste streams. The largest source of energy from wood is pulping liquor or “black liquor,” a waste product from processes of the pulp, paper and paperboard industry. Waste energy is the second-largest source of biomass energy. The main contributors of waste energy are municipal solid waste (MSW), manufacturing waste, and landfill gas. Biomass alcohol fuel, or ethanol, is derived primarily from sugarcane and corn. It can be used directly as a fuel or as an additive to gasoline. Biomass can be converted to other usable forms of energy like methane gas or transportation fuels like ethanol and biodiesel. Rotting garbage, and agricultural and human waste, release methane gas—also called "landfill gas" or "biogas." Crops like corn and sugar cane can be fermented to produce the transportation fuel, ethanol. Biodiesel, another transportation fuel, can be produced from left-over food products like vegetable oils and animal fats. Also, Biomass to liquids (BTLs) and cellulosic ethanol are still under research. The biomass used for electricity production ranges by region. There are a number of technological options available to make use of a wide variety of biomass types as a renewable energy source. Conversion technologies may release the energy directly, in the form of heat or electricity, or may convert it to another form, such as liquid biofuel or combustible biogas. While for some classes of biomass resource there may be a number of usage options, for others there may be only one appropriate technology. Thermal conversion: These are processes in which heat is the dominant mechanism to convert the biomass into another chemical form. The basic alternatives of combustion, torrefaction,, pyrolsiss, and gasification are separated principally by the extent to which the chemical reactions involved are allowed to proceed (mainly controlled by the availability of oxygen and conversion temperature). There are a number of other less common, more experimental or proprietary thermal processes that may offer benefits such as hydrothermal upgrading (HTU) and hydroprocessing. Some have been developed for use on high moisture content biomass, including aqueous slurries, and allow them to be converted into more convenient forms. Some of the applications of thermal conversion are combined heat and power (CHP) and co-firing.In a typical biomass power plant, efficiencies range from 20–27%. Chemical conversion A range of chemical processes may be used to convert biomass into other forms, such as to produce a fuel that is more conveniently used, transported or stored, or to exploit some property of the process itself. Biochemical conversion A microbial electrolysis cell can be used to directly make hydrogen gas from plant matter As biomass is a natural material, many highly efficient biochemical processes have developed in nature to break down the molecules of which biomass is composed, and many of these biochemical conversion processes can be harnessed. Biochemical conversion makes use of the enzymes of bacteria and other micro-organisms to break down biomass. In most cases micro-organisms are used to perform the conversion process: anaerobic digestion, fermentation and composting. Other chemical processes such as converting straight and waste vegetable oils into biodiesel is transesterification. Another way of breaking down biomass is by breaking down the carbohydrates and simple sugars to make alcohol. However, this process has not been perfected yet. Scientists are still researching the effects of converting biomass. Biomass power plant size is often driven by biomass availability in close proximity as transport costs of the (bulky) fuel play a key factor in the plant's economics. It has to be noted, however, that rail and especially shipping on waterways can reduce transport costs significantly, which has led to a global biomass market. One of the major advantages of biomass energy is it's small carbon footprint compared to fossil fuel. As long as new plant material is grown to replace that used, biomass energy produces no net CO2 increase. To make small plants of 1 MW economically profitable those power plants have need to be equipped with technology that is able to convert biomass to useful electricity with high efficiency such as ORC technology, a cycle similar to the water steam power process just with an organic working medium. Such small power plants can be found in Europe. Using biomass as a fuel produces air pollution in the form of carbon monoxide, NOx (nitrogen oxides), VOCs (volatile organic compounds), particulates and other pollutants, in some cases at levels above those from traditional fuel sources such as coal or natural gas. Black carbon - a pollutant created by incomplete combustion of fossil fuels, biofuels, and biomass - is possibly the second largest contributor to global warming. In light of the pressing need to reduce greenhouse gas emissions in the short term in order to mitigate the effects of climate change, a number of environmental groups are opposing the large-scale use of forest biomass in energy production CONCLUSION: Keeping in view the reserves of fossil fuels and the economy concerns, the fuels are likely to dominate the world primary energy supply for another decade but environmental scientists have warned that if the present trend is not checked then by 2100, the average temperature around the globe will rise by 1.4 to 5.8 degrees Celsius, which wil cause a upsurge in the sea water levels drowning all lands at low elevation along the coastal lines. So the world has already made a beginning to bring about the infrastructural changes in the energy sector so as to be able to choose the renewable energy development trajectory. In developing countries, where a lot of new energy production capacity is added the rapid increase of renewable is, in principle easier than in the industrial countries where exixting capacity would need to be converted if a rapid change were to take place. That is developing countries is needed since the majority of the energy technologies in use in developing countries have been developed and commercialized in developed countries first. Nevertheless , India must give more trust to the research and development in the field of non-conventional energy sources not only to mitigate green house effect but also to lessen dependence on oil/gaqs import, which consumes major chunk of foreign exchange reserve. It is also clear that an integrated energy system consisting of two or more renewable energy source has the advantage of stability, reliability and are economically viable. BIBILIOGRAPHY:  “NON-CONVENTIONAL ENERGY RESOURCES” by D.S. CHAUHAN..,  “INTRODUCTION TO NON CONVENTIONAL ENERGY RESOURCES” by Raja AK Manish..,  “NON CONVENTIONAL ENERGY SYSTEMS “by S K Agarwal  “NON CONVENTIONAL ENERGY SOURCES AND UTILISATION“ by R K Rajput…..



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