Introduction to Energy Types of Energy Sources Solar Energy Wind Energy Tidal Energy Hydro Energy Biomass Energy Geothermal Energy 12/2/2015ME 1001 Unit-3 Lecture -11

Definition of Energy: Energy can be defined as the ability (or) capacity to do work Energy can be basically divided into Potential & Kinetic Energies: Potential Energy is the energy that something has due to its position or because of its arrangement of parts. It can also be called stored energy Examples: A coiled spring, Chemicals in batteries etc. Kinetic Energy is the energy possessed by any object in motion. Examples: energy in a ball thrown upward, wind etc. 12/2/2015ME 1001 Unit-3 Lecture -12

The Other types of energy: Energy can be obtained in number of way. It may be in the form of (1) Chemical energy -due to chemical reaction (2) Electrical energy -due to flow of electron (3)Heat energy - due to thermal vibration (4)Light energy -due to radiation of light (5)Mechanical energy – due to moving parts (6)Nuclear energy - due to nuclear reaction (7) Sound Energy -due to vibration of solids, liquids and gases The SI unit of energy is Joule (or) Nm. 12/2/2015ME 1001 Unit-3 Lecture -13

12/2/2015ME 1001 Unit-3 Lecture -14 Law of conservation of energy According to law of conservation of energy, Energy can neither be created nor destroyed. But, one form of energy can be converted to another form. Example:  A battery generates electrons from chemical reactions, which are used to make electrical energy.  A heater convert electrical energy into heat energy.  The human leg converts the chemical energy stored in the muscles into mechanical energy when you pedal a bicycle.

Energy Chains Most of the energy in nature needs to be converted from one form to another before being used. On the basis of availability they can also be classifies as Primary energy resources Secondary energy resources There is also intermediate energy, which is a stage between the other two Primary energy:All energy originating from natural sources such as coal, solar, wind, hydro are called primary energy resources. Secondary energy: The energy converted from primary energy sources. For example, the solar energy can be converted into electricity 12/2/2015ME 1001 Unit-3 Lecture -15

Types of Energy sources 1.Conventional energy sources (or) Non-renewable energy sources 2.Non-Conventional energy sources (or) Renewable energy sources Generally, non-renewable energy sources come out of the ground as liquids, gases and solids. Examples: The conventional (or) Non-renewable energy sources are Oil, Coal, Petroleum and natural gas, Nuclear energy (1)Conventional energy (or) Non-renewable energy Conventional (or) Non-renewable energy sources are those, which cannot be replaced continuously. 12/2/2015ME 1001 Unit-3 Lecture -16

12/2/2015ME 1001 Unit-3 Lecture -17 Conventional Energy sources Fossil Fuels – Fuels formed from plant and animal remains over millennia 1.Solid Fuels –Coal is formed from decay of plant matter. Forms include peat, lignite etc. 2. Liquid Fuels – Petroleum is formed due to decay of marine and extinct spices of life. Forms include petrol, diesel, kerosene etc. 3. Gaseous Fuels – Natural has was also formed due to decay of vegetable matter.

12/2/2015ME 1001 Unit-3 Lecture -18 We can obtain renewable energy from the sun, from the water, from the wind, from crop residues and waste The types of Non-conventional (or) Renewable energies are Solar energy Tidal energy Wind energy Hydro energy Biomass energyBiofuels GeothermalWave Power Non-Conventional energy (or)Renewable energy Renewable energy is a source of energy that can never be exhausted and can be replaced continuously

Earth Receives kwh of solar energy every year The surface of the earth receives about kW from sun 12/2/2015ME 1001 Unit-3 Lecture -19

It is not constantly available on earth. Thus some form of storage is needed to sustain solar energy through the night and during rainy season Solar energy is diffused. 12/2/2015ME 1001 Unit-3 Lecture -110

Flat plate collector Parabolic or concentrating collector 12/2/2015ME 1001 Unit-3 Lecture -111

The absorber plate is metallic. It is usually coated black to absorb more heat energy. Tubes, passages or channels integral with the collector carry water or other working fluid. Insulation should be provided at the back and at the sides to minimize the heat losses. Usually glass wool is used as insulation material. 12/2/2015ME 1001 Unit-3 Lecture -112

The reflector will have a parabolic shape so that the sun rays striking the profile will be reflected on its focal point. If a tube carrying a fluid is kept along the focal line, the fluid will be heated to a very high temperature. 12/2/2015ME 1001 Unit-3 Lecture -113

This system uses a flat plate collector, which can heat water up to about 80 0 C only. Water is circulated through the flat plate collector. Heat exchanger is used to vaporize a low boiling fluid (butane) and the butane vapor will run the turbine 12/2/2015ME 1001 Unit-3 Lecture -114

A receiver is mounted on the tower which is 100 to 500m high reflecting mirrors are known as heliostat. The heliostat are arranged in such a way that they direct the solar energy on the receiver throughout the day. The receiver is designed and positioned in such a way to intercept, absorb and transfer maximum heat to working fluid. The temperature achieved is C to C 12/2/2015ME 1001 Unit-3 Lecture -115

Photovoltaic system 12/2/2015ME 1001 Unit-3 Lecture -116

Photovoltaic conversion Stand alone system Grid-interface system Stand alone systems are for low level application Grid interfaced systems are for the high level and greater power requirement 12/2/2015ME 1001 Unit-3 Lecture -117

Stand alone system 12/2/2015ME 1001 Unit-3 Lecture -118

Grid interfaced system 12/2/2015ME 1001 Unit-3 Lecture -119

Steps involved in selection of PV system Calculation of electrical load Size of PV system PV sub systems(inverters, charge controllers, wiring) Panel mounting Storage( Batteries) Type of PV 12/2/2015ME 1001 Unit-3 Lecture -120

Advantages Renewable source of energy Pollution free After the capital cost, the cost of power generation is quite low Wide range of applications, powering street lights to satellites 12/2/2015ME 1001 Unit-3 Lecture -121

Disadvantages Capital cost is very high Large area of land is required Large number of solar panels are required Affected by seasons. 12/2/2015ME 1001 Unit-3 Lecture -122

Bio Mass Energy Can be obtained for biomass (organic matter) Cheaper for operating the thermal power plants used along with coal. Includes bio mass crops such as hay of paddy, wheat, and corn,bran, animal wastes. 12/2/2015ME 1001 Unit-3 Lecture -123

Bio Power From the organic matter when burnt. Gasification of bio mass (animal wastes, other organic matter) 12/2/2015ME 1001 Unit-3 Lecture -124

Bio Fuels Ethanol (as gasoline) E85 ( ethanol (85%) and petrol (15%)) Bio diesel - alkyl monoesters of fatty acids Jatropha and soya bean Vegetable oils and animal fats 12/2/2015ME 1001 Unit-3 Lecture -125

Advantages Theoretically in exhaustible fuel Less environmental impact Clean burning fuels 12/2/2015ME 1001 Unit-3 Lecture -126

Disadvantages Can cause particulate pollution Expensive production Available on small scale 12/2/2015ME 1001 Unit-3 Lecture -127

Wind Energy Electrical energy can be generated by wind energy by utilizing the kinetic energy of wind Wind mills are classified into two types Horizontal axis wind turbine Vertical axis wind turbine 12/2/2015ME 1001 Unit-3 Lecture -128

Horizontal Axis Wind Turbine 12/2/2015ME 1001 Unit-3 Lecture -129

Vertical Axis Wind Turbine Vertical axis wind turbine can be classified into two types Darrieus type Savonius type 12/2/2015ME 1001 Unit-3 Lecture -130

Advantages Wind Is Renewable And Free Of Cost Pollution free Can be installed in remote villages, thus reducing costly transmission lines 12/2/2015ME 1001 Unit-3 Lecture -131

Disadvantages Capital cost is very high Large area of land is required Very diffused source. maintenance cost is very high Winds direction have an impact on production High speed directional winds and cyclones(hurricanes) may ruin the equipment 12/2/2015ME 1001 Unit-3 Lecture -132

Tidal Energy The large scale up and down movement of sea water represents an unlimited source of energy. The main feature of the tidal cycle is the difference in water surface elevations at the high tide and at the low tide. If the differential head could be utilized in operating a hydraulic turbine, the tidal energy could be converted into electrical energy by means of an attached generator. 12/2/2015ME 1001 Unit-3 Lecture -133

Tidal Power Plant 12/2/2015ME 1001 Unit-3 Lecture -134

Advantages It is inexhaustible source of energy No problem of pollution After the capital cost, the cost of power generation is quite low High output can be obtained compared to solar or wind energy 12/2/2015ME 1001 Unit-3 Lecture -135

Disadvantages Capital cost is very high As the head is not constant, variable output is obtained As the head is low, large amount of water is necessary for the turbine It will not operate when the available head is less than 0.5m 12/2/2015ME 1001 Unit-3 Lecture -136

12/2/2015ME 1001 Unit-3 Lecture -137 Active geothermal places on Earth

Geothermal Energy Geothermal power plants derive energy from the heat of the earth’s interior. The average increase in temperature with depth of the earth is 10C for every 30-40m. At a depth of 10-15km, the earth’s interior is as hot as C. In certain areas of our planet, the underground heat has raised the temperature of water to over C which bursts out as hot steam through the cracks in the earth’s crust. This steam can be utilized for power production. 12/2/2015ME 1001 Unit-3 Lecture -138

Geothermal energy Steam generation is of two kinds Magmatic steam Meteoritic steam Depending up on the type of source Vapour dominated Liquid dominated systems 12/2/2015ME 1001 Unit-3 Lecture -139

Geothermal Power Plants Geothermal wells are drilled at suitable locations. Water vaporized into steam comes out of the earth’s surface in a dry condition at around C and 8 bar. This steam will run the turbine coupled with a generator. Steam is condensed in a condenser and re injected back into the ground by a rejection well 12/2/2015ME 1001 Unit-3 Lecture -140

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Advantages Geothermal energy is cheaper Used as space heating for buildings Used as industrial process heat Geothermal energy is inexhaustible 12/2/2015ME 1001 Unit-3 Lecture -143

Disadvantages Low overall power production efficiency (about 15%) Drilling operation is noisy Large areas are needed for exploitation of geothermal energy 12/2/2015ME 1001 Unit-3 Lecture -144

Ocean Thermal Energy Conversion OTEC uses the temperature difference of the sea water at different depths to generate electricity 12/2/2015ME 1001 Unit-3 Lecture -145

Ocean Thermal Energy Conversion OTEC utilizes the temperature difference that exists between the surface waters heated by the sun and the colder deep (up to 1000m) waters to run a heat engine. This source and sink provides a temperature difference of 20 0 c in ocean areas within 2 0 of the equator. Such a small temperature difference makes energy extraction difficult and expensive. 12/2/2015ME 1001 Unit-3 Lecture -146

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Merits and Demerits Available throughout year No special equipment required for energy conversion Less efficiency 3% Large tubing required Chances of temperature leak out Impact on coral life 12/2/2015ME 1001 Unit-3 Lecture -149

Nuclear Energy Fission and fusion reactions causes enormous energy which can be used in production of electricity Uranium dioxide Plutonium dioxide 12/2/2015ME 1001 Unit-3 Lecture -150

Merits and Demerits Less fuel can cause plenty of heat energy Suitable for large scale energy production Compact in size High installation cost and expertise Disposal of wastes Maintenance cost is very high Highly skilled professionals required Risk involved in radiation 12/2/2015ME 1001 Unit-3 Lecture -151

Nuclear power plant 12/2/2015ME 1001 Unit-3 Lecture -152