BMS Institute Of Technology And Management Module 1 PDF

Three problems with burning fossil fuels are air pollution, water pollution, and soil pollution. 22-10-2023 1 22-10-2023 2 22-10-2023 3  Solar Radiation The sun is the source of all forms of energy. The intensity of sunlight at the surface of the e...

Three problems with burning fossil fuels are air pollution, water pollution, and soil pollution. 22-10-2023 1 22-10-2023 2 22-10-2023 3  Solar Radiation The sun is the source of all forms of energy. The intensity of sunlight at the surface of the earth is at most about one thousand watts per square meter. 22-10-2023 4  Solar Energy Solar energy refers to the energy produced and radiated by the sun. Solar energy is radiant energy emitted by the sun, it is also known as solar power. Solar energy can be converted directly or indirectly into other forms of energy, such as heat and electricity.  Solar energy may then be used in various ways, which may be divided broadly into two classes as: a) Direct thermal applications: Helio-electrical and Helio- thermal process b) Indirect thermal applications: Biomass energy (Helio- chemical), wind energy, tidal energy, ocean thermal energy 22-10-2023 5 etc.  Helio-electrical Process Solar cells are devices in which sunlight releases electric charges so they can move freely in a semiconductor and ultimately flow through an electric load, such as a light bulb or a motor. A Solar cell or photovoltaic cell is an electrical device or specialized semiconductor device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. The phenomenon of producing voltages and currents in this way is known as the photovoltaic effect. The photovoltaic effect is a process in which a light- sensitive semiconductor converts the visible light(sun light) into a voltage or into a direct current. 22-10-2023 6  Conversion of solar energy into electrical energy can be achieved by the photovoltaic effect caused by the solar radiations using semiconductors (like silicon). Si can be “doped” with other elements to change its electrical properties. Silicon is a tetravalent material i.e It has four valence electrons after doping it with pentavalent material (like arsenic, phosphorous), it forms N-type semiconductor. i.e, if Si is doped with phosphorus (P), each P atom can contribute a conduction electron, so that the Si lattice has more electrons than holes, i.e. it becomes “N type”. 22-10-2023 7  Similarly when silicon is doped with trivalent material (like boron) it forms P-type semiconductor. i.e, If Si is doped with Boron (B), each B atom can contribute a hole, so that the Si lattice has more holes than electrons, i.e. it becomes “P type”: When this P-N junction of semiconductor is exposed to sunlight, a voltage around 0.5 volts is built up around the junction and current is produced. Current produced depends on the exposed area of cell. 22-10-2023 8  The stronger the sun, the more electric energy is produced. Nevertheless, the cells do not need direct sunlight to work, and they can still produce electricity on a cloudy day. It is a form of photoelectric cell defined as a device whose electrical characteristics such as current, voltage or resistance, vary when exposed to light. Silicon solar cells are important in the space program for the conversion of photon radiation to electrical power. 22-10-2023 9 22-10-2023 10 22-10-2023 11 22-10-2023 12  The solar collector is a device to collect solar energy, and transform it into thermal energy, by using heat transfer fluid like water, air or ethylene glycol. For example, consider cold climates, the low grade thermal energy is required to heat air for comfort, hot water for washing, cleaning and other domestic and industrial needs. A flat plate collector is simple in construction and does not require tracking. So it can properly secured on a rigid platform These collectors are installed outside or outdoor applications. These are exposed to atmospheric disturbances like rain, storms and any other kind of disturbances. 22-10-2023 13 22-10-2023 14 The construction of a flat plate collector consists of 5 primary components; 1. The absorber plate, 2. Tubes fixed to that absorber plate, 3. Transparent cover, 4. Collector box 5. Insulation 22-10-2023 15  The irradiation incident on a collector is not all absorbed. Once the irradiation penetrates the glass cover, part of it is absorbed by the collector, but another part is reflected back diffusely to the glass cover. 22-10-2023 16 22-10-2023 17 22-10-2023 18 22-10-2023 19 22-10-2023 20 22-10-2023 21 22-10-2023 22 22-10-2023 23 22-10-2023 24 22-10-2023 25 22-10-2023 26  Wind Energy 22-10-2023 27  Wind power or wind energy is the use of wind to provide the mechanical power through wind turbines to operate electric generators. Wind power is a sustainable and renewable energy. Wind possesses energy by virtue of its motion. Wind energy is a form of solar energy. 22-10-2023 28 Wind Generation Wind results from the movement of air due to atmospheric pressure gradients. Wind flows from regions of higher pressure to regions of lower pressure. The larger the atmospheric pressure gradient, the higher the wind speed and thus, the greater the wind power that can be captured from the wind by means of wind energy-converting machinery. 22-10-2023 29  Wind is caused by the uneven heating of the atmosphere by the sun, variations in the earth's surface, and rotation of the earth. Wind speeds vary based on geography, topography and season as a result, there are some locations better suited for wind energy generation. Wind power is the conversion of wind energy into electricity or mechanical energy using wind turbines. Wind turbines convert the kinetic energy in the wind into mechanical power. A generator can convert mechanical power into electricity. 22-10-2023 30 22-10-2023 31  Wind Turbine Wind energy conversion devices are commonly known as wind turbines. It consists of a number of vanes or blades radiating from a hub or central axis. When the wind blows against the vanes of a wind turbine, rotational motion is caused in the wind turbine. Thus, kinetic energy of wind is converted into mechanical work. Kinetic energy of wind can be converted into mechanical energy utilized to perform useful work or to generate electricity. The amount of power transferred is dependent on the rotor size and the wind speed. 22-10-2023 32  Wind energy conversion devices are commonly known as wind turbines. It consists of a number of vanes or blades radiating from a hub or central axis. When the wind blows against the vanes of a wind turbine, rotational motion is caused in the wind turbine. Thus, kinetic energy of wind is converted into mechanical work. Kinetic energy of wind can be converted into mechanical energy utilized to perform useful work or to generate electricity. The amount of power transferred is dependent on the rotor size and the wind 22-10-2023 33 speed.  Blades are made of FRP (GFRP/CFRP) 22-10-2023 34 22-10-2023 35  Wind energy is the energy contained in the wind blowing across the earth’s surface.  Wind speed and the height of the blades both contribute to the amount of energy generated.  The wind turns the blades, which spin turbine shaft. This shaft is directly coupled to a generator where electricity is generated.  The energy in the wind turns three propellers-like blades around a rotor.  The rotor is connected to the main shaft, which spins a generator to produce electricity.  Wind turbines are mounted on a tower to capture maximum energy from the wind. At 100 feet (30 meters) or more above the ground.  They can take advantage of faster and less turbulent wind. 22-10-2023 36 22-10-2023 37 22-10-2023 38  Nacelle: The rotor attaches to the nacelle, which sits atop the tower and includes the gear box, low- and high- speed shafts, generator, controller, and brake 22-10-2023 39 22-10-2023 40 22-10-2023 41 22-10-2023 42 22-10-2023 43 22-10-2023 44 22-10-2023 45 22-10-2023 46 22-10-2023 47 Advantages of wind energy Operation and maintenance costs are less. Fuel cost is nil and is non-polluting. Helps in generating power to houses located off-shore and on- shore remote areas. Reliable at elevated sites. Limitations of wind energy Noisy during operation. Large hilly areas are require d for large power generation. Needs storage batteries. Fluctuations in amount of power generated due to time of the day, location etc 22-10-2023 48  Hydropower or Hydroelectric Power Plant Hydropower is considered as one of the most economic and non polluting sources of energy. Power generated from water is known as hydroelectricity. Hydroelectricity means electricity generated by hydropower or from the use of the gravitational force of falling of flowing water. Hydroelectric power plants are used to convert the hydraulic potential energy from water into electrical energy. Hydro-electric power stations are generally located in hilly areas where dams can be built and large water reservoirs can be obtained. 22-10-2023 49  Hydro Electric Energy Hydraulic energy is the indirect source of solar energy Hydraulic energy Converts the energy of flowing water into electricity. The water flowing in the river possesses two type of energy: (1) The kinetic energy due to flow of water and (2) Potential energy due to the height of water. 22-10-2023 50  Water stored in high-elevation reservoir held by dams creates high- pressure water at the bottom of the dam. The energy stored in the high-pressure water can be converted to shaft work using hydroelectric turbines to produce electricity. 22-10-2023 51 Major components are: Dams Spillways Headwork Surge Tanks Penstock Power Stations 22-10-2023 52 Working of Hydroelectric Power Plant A dam is constructed across a water body. Water from the catchment area collects at the back of the dam to form reservoir. Water is brought to valve house at the start of penstock. The valve house contains main sluice valves and automatic isolating valves. Water is taken to water turbine through a huge steel pipe known as penstock. The water turbine converts hydraulic energy into mechanical energy. The turbine drives the alternator which converts mechanical energy into electrical energy. 22-10-2023 53 Advantages of hydro electric energy  Environment-friendly.  Hydraulic turbines are robust. As they are operating at low speed, there are less mechanical problems.  Hydro reservoirs help in agriculture and to control floods.  Maintenance and operating cost is low. Limitations of hydro electric energy  Leads to deforestation and relocation of people living in surrounding regions.  Requires large quantity of water  Rainfall affects the delivery of power  Construction of dams is costly.  As the sites of hydro electric stations are usually far away from the load centers, the cost of transmission is high. 22-10-2023 54