Power point of unit 1 Hybrid Energy System

Unit 1 PPT for hybrid energy system

1. EE3033 HYBRID ENERGY TECHNOLOGY

2. UNIT 1 INTRODUCTION TO HYBRID ENERGY SYSTEMS

3. Renewable Energy Renewable energy is defined as the energy sources that are natural and continually refilled either at the same rate or faster than the rate at which they are being used up by humans indefinitely. For Example : sun, wind, rain, tides, biomass and geothermal energy.

4. HYBRID RENEWABLE ENERGY SYSTEMS Hybrid renewable energy systems  (HRES) are becoming popular as stand-alone power systems for providing electricity in remote areas due to the advancements in renewable energy technologies. A hybrid energy system usually consists of two or more renewable energy sources connected together to provide power to the load with increased system efficiency, increased reliability.

5. CONFIGURATION

6. Need for Hybrid Energy Systems Hybrid energy systems combine two or more different energy sources or storage technologies to provide a more reliable, efficient, and sustainable power supply. There are several reasons why hybrid energy systems are needed: Increased Reliability: By combining multiple energy sources, hybrid systems can provide a more reliable power supply. If one source experiences downtime or fluctuation, the system can switch to an alternative source, ensuring uninterrupted power supply. Enhanced Efficiency : Hybrid systems can optimize energy production by utilizing the strengths of each energy source. For example, solar panels generate electricity during the day, while wind turbines may produce power at night or during cloudy weather. Combining these sources can provide a more consistent energy output. Energy Security: Diversifying energy sources reduces dependence on a single energy resource, which can enhance energy security. This is particularly important in regions reliant on imported fossil fuels, where geopolitical factors or supply disruptions can affect energy availability. Environmental Benefits: Integrating renewable energy sources like solar, wind, or hydroelectric power into hybrid systems reduces reliance on fossil fuels, leading to lower greenhouse gas emissions and mitigating climate change. Hybrid systems can also help to address the intermittency issues associated with renewable energy sources by integrating them with other energy sources or storage technologies. Cost Savings : Hybrid systems can potentially reduce energy costs by optimizing the use of available resources. For instance, combining a renewable energy source with a traditional fossil fuel generator can reduce fuel consumption and operating costs. Off-Grid Solutions : In remote or rural areas where access to the main power grid is limited or nonexistent , hybrid energy systems can provide a viable off-grid solution. These systems can combine renewable energy sources with energy storage technologies to meet the energy needs of isolated communities or facilities. Scalability : Hybrid systems are often scalable and adaptable to varying energy demands. They can be designed to accommodate changes in energy requirements over time, making them suitable for both small-scale and large-scale applications. Overall, the need for hybrid energy systems stems from the desire to create more resilient, efficient, and sustainable energy solutions that can address the challenges of climate change, energy security, and economic sustainability.

7. Solar-wind-diesel HES

8. Wind- Biomass-Diesel HES

9. PV/HYDRO HYBRID SYSTEM A typical hybrid energy system consists of solar PV panel and wind energy sources. A solar PV panel and Wind Turbine Generator form a good pair of inputs to the hybrid power supply as they naturally complement each other . The sun light is dominant during the day time and it produces energy, while the wind is less during day time Similarly, during the night time the wind is dominant while there is no sunlight. As they complement each other, we shall have continuous supply of power as solar PV panel supplies during the day time, while WTG supplies during the night time. An open loop hybrid power system with solar PV panel and Wind Turbine Generator is shown in the Figure.

10. Micro-Hydel-PV HES

11. When Induction Generator (IG) (or) Permanent Magnet Synchronous Generator is used, the output of WTG is in the form of AC voltage and also the power delivered by the WTG is continuously varying as the output power depends on the wind speed which is continuously varying. The power output of WTG is given by, The variable amplitude and frequency of WTG is converted into DC by using a AC-DC converter (phase controlled rectifier) to charge the battery. A dedicated controller protects the battery from overcharging or deep discharging. As most of the loads are AC loads, an inverter is connected to the battery to transform the low DC voltage to an AC voltage of 230V of frequency 50 Hz.

12. Classification of Hybrid Energy systems

13. Characteristics of Distributed energy resources are Normally located at or near the point of use, Location value and Distribution voltage

14. Importance of Hybrid Energy systems Hybrid energy systems play a crucial role in addressing various challenges and fulfilling key objectives in the energy sector. Here are some important aspects of their significance: Reliability : Hybrid energy systems enhance energy reliability by combining multiple energy sources. This reduces the risk of power outages or supply disruptions, ensuring continuous electricity supply even during adverse weather conditions or fluctuations in energy availability. Energy Security : By diversifying energy sources, hybrid systems reduce dependence on a single energy resource or supplier, thus enhancing energy security. This is particularly significant in regions heavily reliant on imported fossil fuels, where geopolitical factors or supply disruptions can impact energy availability. Optimized Performance : Hybrid systems leverage the strengths of different energy sources to optimize performance. For example, combining solar and wind power can provide a more consistent energy output throughout the day and night, reducing intermittency issues associated with individual renewable sources. Environmental Sustainability : Hybrid energy systems promote environmental sustainability by incorporating renewable energy sources and minimizing reliance on fossil fuels. This helps reduce greenhouse gas emissions, mitigate climate change, and preserve natural resources for future generations. Cost Efficiency : Integrating renewable energy sources into hybrid systems can lead to cost savings over the long term. While initial investments may be higher, the use of free and abundant renewable resources like sunlight and wind reduces operating costs and dependence on expensive fossil fuels, resulting in overall cost efficiency. Scalability and Adaptability : Hybrid systems are often scalable and adaptable to varying energy demands and conditions. They can be designed to accommodate changes in energy requirements over time, making them suitable for both small-scale and large-scale applications, including off-grid and grid-connected systems. Technology Integration and Innovation : Hybrid energy systems drive innovation and technological advancements in the energy sector. The integration of multiple energy sources, storage technologies, and control systems fosters the development of new solutions and improves the efficiency and effectiveness of energy generation and distribution. Access to Energy : Hybrid systems can provide reliable and sustainable energy access to remote or underserved communities that are not connected to the main power grid. By combining renewable energy sources with energy storage and backup options, these systems enable off-grid electrification and contribute to poverty reduction and socio-economic development. In summary, the importance of hybrid energy systems lies in their ability to enhance energy reliability, security, and sustainability while promoting cost efficiency, innovation, and equitable access to energy. These systems represent a vital component of the transition towards a more resilient, efficient, and environmentally friendly energy infrastructure .

15. ADVANTAGES OF HYBRID RENEWABLE ENERGY SYSTEMS (HRES) Enhanced reliability : The reliability in continuity of supply is increased in renewable energy than with individual technologies. Lower emission : HRES can be designed to maximize the use of renewable resources, resulting in a system with lower emissions than traditional fossil-fuelled technologies. Acceptable Cost (Optimize generation costs) : HRES can be designed to achieve desired attributes at the lowest acceptable cost, which is the key to market acceptance. Operational flexibility : Provide operational flexibility over traditional renewable plants.

16. Advantages of Renewable Energy Sources Major advantage of RES is that it is renewable (or) sustainable and therefore it will never run out. Renewable energy facilities generally require less maintenance than traditional generators. The fuel being derived from natural and available resources reduces the costs of operation. Renewable energy produces little or no waste products such as carbon dioxide or other chemical pollutants and hence has minimal impact on the environment. Renewable energy projects can bring economic benefits to many regional areas, as most projects are located away from large urban centers and suburbs of the capital cities.

17. DISADVANTAGES OF HYBRID RENEWABLE ENERGY SYSTEMS (HRES) While hybrid energy systems offer numerous advantages, they also come with certain disadvantages. Here are some drawbacks to consider: Complexity : Hybrid energy systems can be complex to design, install, and maintain due to the integration of multiple energy sources, storage technologies, and control systems. This complexity may require specialized knowledge and expertise, leading to higher upfront costs and operational challenges. Cost : While hybrid systems can provide long-term cost savings through reduced reliance on fossil fuels and lower operating costs, their initial capital costs can be higher compared to conventional energy systems. Investments in renewable energy technologies, energy storage, and hybrid system integration may require significant upfront expenditures. Space Requirements : Depending on the combination of energy sources used, hybrid energy systems may require considerable space for installation. Solar panels, wind turbines, and energy storage facilities can occupy large land areas, which may be a limitation, especially in densely populated or urban areas. Intermittency and Variability : Hybrid systems that rely on renewable energy sources like solar and wind power may experience intermittency and variability in energy generation. This can pose challenges in meeting constant energy demand, particularly during periods of low sunlight or wind speeds. Backup power sources or energy storage systems are needed to address these fluctuations, adding complexity and cost to the system. Environmental Impact : While hybrid energy systems reduce reliance on fossil fuels and mitigate greenhouse gas emissions, they may still have environmental impacts. For instance, the manufacturing, installation, and disposal of renewable energy technologies and energy storage systems can generate carbon emissions and produce waste. Additionally, the environmental footprint of hybrid systems depends on factors such as the energy mix, location, and land use. Maintenance Requirements : Hybrid energy systems require regular maintenance and monitoring to ensure optimal performance and reliability. Components such as solar panels, wind turbines, batteries, and control systems may require periodic inspection, cleaning, and repairs. Maintenance activities can add to the operational costs and downtime of the system. Resource Availability : The effectiveness of hybrid energy systems depends on the availability and reliability of the energy sources used. Factors such as sunlight, wind speed, and water availability can vary based on location, season, and weather conditions, affecting the overall performance and efficiency of the system. Technological Challenges : Integrating multiple energy sources and storage technologies into a hybrid system may pose technological challenges such as compatibility issues, energy conversion losses, and system optimization complexities. Advancements in technology and research are needed to overcome these challenges and improve the efficiency and effectiveness of hybrid energy systems. Overall, while hybrid energy systems offer numerous benefits, it's essential to consider these disadvantages and challenges in their implementation and operation. Effective planning, design, and management are crucial for maximizing the advantages of hybrid systems while mitigating their drawbacks .

18. Present Indian scenario of conventional and RE sources

19. IMPACTS OF RENEWABLE ENERGY GENERATION ON ENVIRONMENT (COST-GHG EMISSION)

20. ENVIRONMENTAL IMPACTS OF WIND POWER A wind farm, when installed on agricultural land has lowest environmental impacts than all other energy sources, It occupies less land area per kilowatt-hour (kWh) of electricity generated than any other energy conversion system. It is compatible with grazing of cattle's and farming crops. It generates the energy used in its construction in just 3 months of its operation, yet its operational lifetime is 20-25 years. Greenhouse gas (GHG) emissions and air pollution produced during its construction and operation are very tiny. No emissions or pollution is produced by WTG during its operation, hence in substituting for base load (mostly in place of coal power), the wind power causes a considerable reduction in GHG emissions and air pollution. Modern wind turbines are almost silent and rotate so slowly (in terms of RPM), hence they are rarely a threat to birds and hence protects biodiversity. Modern wind turbine designs have significantly reduced the noise from the turbines. Turbine designers are working to minimize noise, as noise reflects loss of energy.

21. Low frequency sound and infrasound (i.e. usually beneath the threshold of human hearing) are emitted from wind turbines. Modern turbine designs which locate the blades in the upwind instead of downwind have significantly reduced the level of infrasound. Scientific and health authorities had ensured the low level of infrasound emitted by wind turbines create no health risks. Wind turbines create shadow flicker on nearby residences when the sun passes behind the turbine. However, this can easily be avoided by locating the wind farm to avoid unacceptable shadow flicker, or turning the turbine off for the few minutes of the day when the sun is at the angle that causes flicker. Many energy policy studies have noted how wind turbines present direct and indirect hazards to birds and bats. Birds may directly smash into moving or even stationary turbine blades, crash into towers and nacelles, and collide with local distribution lines. The risk gets worse when turbines are placed on ridges and upwind slopes or built close to migration routes . Some species, such as bats, face additional risks from the rapid reduction in air pressure near turbine blades, which can cause internal blood losing.

22. ENVIRONMENTAL IMPACTS OF SOLAR POWER Photovoltaic (PV) is now a proven technology which is inherently safe, as opposed to some dangerous electricity generating technologies. In its estimated lifetime a PV module produce much more electricity than was used in its production. A 100W module will prevent the emission of over two tones of CO 2 . Photovoltaic systems make no noise and cause no pollution while in operation. PV cell technologies have relatively lower environmental risks compared to other types of electric sources. However, the chemicals used in PV cells could be released to air, surface water, and groundwater in the manufacturing facility , the installation site, and the disposal or recycling facility. The production of photovoltaic devices involves the use of a variety of chemicals and materials. The amounts and types of chemicals used will vary depending upon the type of cell being produced. Based on a review of chemical information reported, it appears that most of the chemicals used by the manufacturing companies are not released in reportable quantities.

23. The release of chemicals to the air from the photovoltaic facilities was reported as both air stack emissions and fugitive air emissions. The large quantities chemicals released in to air as pollutants includes trichloro-ethane, acetone, ammonia, isopropyl alcohol, and methanol. The scale of the system plays a significant role in the level of environmental impact. - Larger utility-scale solar facilities can raise concerns about a) Land degradation b) Habitat loss and c) Impacts from utility scale solar systems It can be minimized by locating them at low quality locations (abandoned mining land, or existing transmission corridors) Solar PV cells do not use water for generating electricity. but, water is used in the manufacturing processes of solar PV components. Concentrating solar thermal plants (CSP), like all thermal electric plants, require water for cooling. The use of water depends on the plant design, plant location, and the type of cooling system.

24. ENVIRONMENTAL IMPACTS OF GEOTHERMAL ENERGY POSITIVE IMPACT Geothermal power is a gentle source of energy. In most of the cases, the impacts are positive . Worldwide, the use of geothermal energy is increasing as the attractive alternative fossil fuels. Electricity generation using geothermal resources involves much lower greenhouse gas (GHG) emission rates than that of fossil fuels. For same amount of power generation, the geothermal PP produces 95% less co 2 compare to fossil fuel based PP.

25. NEGATIVE IMPACT A large-scale construction and drilling operation will produce Visual impacts on the landscape, Create noise and wastes and Affect local economies. Environmental issues usually addressed during the development of geothermal fields include air quality – Should meet out the stringent air standards water quality – Protection of ground water is important during the drilling phase waste disposal, geologic hazards, noise, Soil protection biological resources and land use issues.

26. ENVIRONMENTAL IMPACTS OF BIOMASS: NEGATIVE IMPACT Biomass power plants share some similarities with fossil fuel power plants, i.e., it involves the combustion of a feedstock to generate electricity . Thus the biomass PP raise concerns about air emissions and water use as fossil fuel plants. It contributes to global warming due to burning or gasifying the feedstock of all types of biomass. POSITIVE IMPACT Biomass PP cleans the agricultural residues such as wheat straw or corn Stover, sustainably - harvested wood and forest residues, and clean municipal and industrial wastes for the production of electrical energy, and hence in a way keep the environment cleaner.

27. ENVIRONMENTAL IMPACTS OF HYDROELECTRIC POWER POSITIVE IMPACT The hydroelectric power stations does not degrade the air quality NEGATIVE IMPACT Large dams use a large area of land for flooding of water as reservoir which destroys local animals and habitats. Large amounts of plant life are submerged Worldwide 40 to 80 million people have been displaced physically by dams causing the change in their life style and customs. Because of dams, the migratory pattern of river animals like salmon and trout are affected . Dams restrict sediments that are responsible for the fertile lands downstream. Large dams are breeding grounds for mosquitoes and cause the spread of disease. Dams serve as a heat sink, and the water is hotter than the normal river water this warm water when released into the river downstream can affect animal life.

28. ENVIRONMENTAL IMPACTS OF OCEAN THERMAL ENERGY CONVERSION NEGATIVE IMPACT The OTEC power station impacts the surrounding marine environment mainly through , Heating the water, Release of toxic chemicals, Destruction of the life of aquatic organisms by intake pipes - Due to collision on intake pipe, - Carried along by the intake by to the top The continual use of warm surface water and cold deepwater over long periods of time, leads to slight warming at depth and cooling at the surface Causes high mortality among corals and fishes Reduces the hatching of eggs Small amount of Co 2 is released in to atmosphere.

29. ENVIRONMENTAL IMPACTS OF WAVE ENERGY POSITIVE ENVIRONMENTAL IMPACT Wave power plants act as wave breakers, calming the sea which is often desired in many harbours. The dampening of waves may reduce erosion on the shoreline ; whether this effect is beneficial or detrimental depends on the specific coastline. NEGATIVE ENVIRONMENTAL IMPACT Covering large area of ocean surface with wave energy devices would harm marine life and could alter the way the ocean interacts with the atmosphere. Artificial structures may simply push the organisms away from their natural habitats which potentially increase the vulnerability of getting harvested.

30. ENVIRONMENTAL IMPACTS OF HYDROGEN ENERGY POSITIVE ENVIRONMENTAL IMPACT Hydrogen can be produced from carbon-free energy sources which eventually eliminate greenhouse gas emissions Fuel cells can provide efficient and clean electricity generation from few watts to kilowatts. In mature hydrogen oriented economy, the introduction of hydrogen fuelled vehicles could reduce the average greenhouse gas emissions from the passenger car fleet.

31. SOLAR ENERGY Block Diagram Representation of Solar Thermal Power Plant

32. Types of Solar Collectors FLAT Plate Collector CONCENTRATED Solar Power Collectors TYPES of concentrated collector: Parabolic trough Parabolic dish Power tower Fresnel reflector

33. Flat Plate Collector When the temperature generation below 90˚C is adequate , the flat plate collector shall be used. Black Chrome Black Nickel Black Copper COATING:

34. Essential Components of Flat Plate Collector A transparent cover which may be is usually a sheet of glass or radiation transmitting plastic film forms the top most cover . It allows the solar radiation to PASS through it, while it will not allow the IR rays to escape from the collector. Transparent to - Solar Radiation (wavelength less than 2 μ m) Opaque to - IR Rays (longer wavelength) Tubes, fins, passages or channels forms the integral part with the collector absorber plate or connected to it, which carry water, air or other fluid. The absorber plate normally metallic or with a black surface although a wide variety of materials can be used with air heaters. Usually Copper, Steel, Aluminum with tubing of copper is generally used as the absorber. The cold water enters the base of the solar thermal heater and after getting heated up, it moves to the top of the collector and gets collected in the tank.

35. Thermal Insulation (usually 5 to 10cm thickness) is provided at the back and at the sides of the collector to minimize the heat losses. Standard insulating materials such as fibre glass or styro foam are used for this purpose. The casing or containers is used to enclose the component and protects them from weather. WATER FLOW in Flat Plate Collector

36. Flat Plate Collector Power Generating System

37. The Flat plate collector, heats the water up to 70˚C. In the Heat Exchanger, the heat of the water is used to boil the butane (the boiling point of butane is less i.e., -1˚C) The butane vapor operates the butane turbine, which supplies mechanical energy to the generator to generate electrical energy. The exhaust butane vapor from the butane turbine is condensed in the CONSENSER with the help of water and the condensate is pumped to boiler using a pump. The advantage of the flat plate collector based power generation system is that, it accepts both the direct and diffused radiation.

38. CONCENTRATED SOLAR POWER COLLECTORS 1. PARABOLIC TROUGH SOLAR COLLECTOR (PTSC) Parabolic Trough Solar Collectors are made by bending a sheet of reflective surface into a parabolic shape . The receiver is made of a black metal tube, that is covered with a glass tube to decrease the convective heat loss is placed along the focal line of the parabolic trough collector to collect the solar energy reflected by the parabolic trough. The glass tube has the property of Transparent to - Solar Radiation (wavelength less than 2 μ m) Opaque to - IR Rays (longer wavelength) The concentrated collector focuses all the direct radiation in to the focal line of the parabolic through that generates higher temperature. It generates the temperature in the range of 250˚ - 500˚C.

39. The surface of receiver is coated with a selective absorber coating that has a high absorptance for solar radiation and low emittance for thermal radiation loss. The working fluid circulated through the receiver is heated to a high temperature by the energy of these higher rat sunlight focussed on the focal line. The hot fluid from the receiver is piped to a heat engine, which uses the heat energy of the fluid to rotate a turbine which generates mechanical energy to turn the generator to produce electricity . PTSC with evacuated tubular receivers is the main technology currently used in solar thermal electrical power plants because of considerable experience with the system

40. 2. PARABOLIC DISH CONCENTRATOR (PDC) Major problem with linear arrays is that it is difficult to achieve high concentration ratio that is required for high temperatures . In order to generate high temperature in the working fluid / gas, parabolic dish concentrators (concave shaped disc) which has very high concentration ratio were used. Parabolic dish focuses the sunlight that strikes on the upper surface of dish on to a single point, where the working fluid/ gas which is to be heated is placed. The curve of each dish make the sun's rays to focus in a small central point, thus reducing heat losses and enabling water passing through that point to be heated to a high temperature. The heated working fluid is taken to a heat engine which rotates the turbine to generate electricity. The Parabolic dish concentrators remain constantly focused on the sun i.e., it aligns itself in the direction of sun with the aid of sun-tracking devices.

41. 3. SOLAR POWER TOWER The solar power tower also called the ‘central tower’ is a concentrating type solar thermal power generating station. It essentially consists of central receiver mounted on the top of a tower surrounded by (of) focussed by thousands of large, sun-tracking flat mirrors called heliostats to concentrate the sunlight onto the receiver. These heliostats controlled by a two axis tracking system continuously track the sun movement to concentrate its radiation energy on the receiver as long as the sun shine is available. The mirrors (i.e.,) heliostats are installed on the ground and are oriented so as to reflect the direct beam radiation in to an absorber (or) receiver (or) boiler, which is mounted on the top of the tower. The beam radiation incident on the boiler is absorbed by the black pipes in which the working fluid is circulated. Water is the convenient heat transport fluid, and in the form of steam, it is the major working fluid in the majority of power generating systems. In advanced central receiver systems, the heat transport fluid is a liquid sodium or molten mixture of salts.

42. At the bottom of the tower, the high temperature liquid (molten salt) is circulated through a heat exchanger, where the heat is transferred to water to produce steam at a higher temperature and pressure. A typical steam condition might be a temperature of 500˚C and pressure of 100 atm (10Mpa) The steam which is coming out of the evaporator is super heated with the hot salt. The super heated steam is piped to ground level where it drives a high pressure (HP) turbine to generate mechanical energy. The exhaust heat from the HP turbine is reheated with the Reheater and is pumped back to the low pressure (LP) turbine. This system allows harvesting the advantages of both the LP turbine and HP turbine.

43. SOLAR PHOTO-VOLTAIC ENERGY CONVERSION Solar PV Cell: Photovoltaic (PV) cells are made of semi-conducting material that generates electrical energy when they absorb light. PV cells work on the phenomena called the photo voltaic effect. The Photovoltaic effect is defined as the generation of an electromotive force as a result of the absorption of ionizing radiation. Construction: In the intrinsic semiconductor i.e., silicon, pentavalent impurities such as arsenic or phosphorous is doped to form the N-type semiconducting material. Also, trivalent impurity such as boron is doped to form the P-type semiconducting material. When both the doped pieces are joined together it forms a P-N junction diode, which forms a PV cell.

44. When a photon in the form of sunlight hits or strikes the PN-junction of the solar cells, the energy from the photon dislodges or knocks loose any free electrons within this PN-junction as they become excited by the photons energy. This results in the electrons being released and able to move freely across the depletion layer leaving in its place a hole or a positive charge. In the P-type material, these free electrons easily cross through the depletion layer and into the N-type material, but this movement of electrons is one-way, as the electrons are not able to cross the depletion layer back into the P-type material. As a result, an excess of free electrons builds up in the N-type semiconductor material creating an electrical current within the solar cell and will continue indefinitely as long as there is exposure to sunlight. Most photovoltaic solar cells produce a “no load” open circuit voltage (nothing connected to it) of about 0.5 to 0.6 volts when there is no external circuit connected.

45. Types of solar cells Amorphous Crystalline Mono crystalline silicon Poly crystalline silicon Thin film silicon

46. From equivalent circuit, the current equation can be written as, Where, ‘ I s ’ is the light generated current in amps ‘ I d ’ is the diode current in amps under a given solar irradiation It can be rewritten as, Where, ‘I o ’ - reverse saturation current in amps ‘V s ’ - terminal voltage of PV module in volts ‘R s ’ - series resistance, ‘ R sh ’ - shunt resistance, ‘q’ - electronic charge (1.6×10 -19 C), ‘A’ - PN junction ideality factor (a dimensionless factor), ‘K’ - Boltzmann constant (1.38×10-23 J/K), ‘T’ - temperature in 0˚C When, R s equals zero and that R sh equal infinity

47. When, R s equals zero and that R sh equal infinity PV module consists of „n‟ number of cells connected in series

48. The I-V characteristics & Maximum power point of a PV array

49. Solar PV power system Block diagram representation of PV system involving solar panel, battery, charge controller and inverter Charge Controllers PWM Charge Controllers Maximum Power Point Tracking (MPPT) Charge Controller

50. WIND ENERGY The kinetic energy possessed by wind is converted into mechanical energy, which rotates the blade and spin the shaft of the turbine, which produces electricity through generator . Wind Turbine Generators are manufactured with the capacity from tens of watts to several megawatts, and diameters of about 1m to more than 100 m. WTG are accepted as ‘mainstream generation’ for utility grid networks in many countries e.g., in Europe, the USA and parts of India and China Smaller wind turbine generators are common for isolated and autonomous power production.

51. Advantages of Wind Energy: It is a “free” source of energy. Like solar Energy, it also produces no water or air pollution Wind farms are relatively inexpensive to build Land around the wind farms can be used for other uses Disadvantages of Wind Energy: Requires constant and significant amounts of wind, but in majority of places it is available in dilute and fluctuating in nature. Wind Energy systems needs storage capacity because of its irregularity Wind farms require significant amounts of land Can have a significant visual impact on landscapes Wind energy systems are noisy in operations

52. BASIC PRINCIPLE OF WIND ENERGY CONVERSION Power in the Wind Power Coefficient:

53. COMPONENTS OF WECS

54. Wind Mill Head The wind mill head supports, Rotor Hub , Rotor blades Pitch Controls Transmission and Gearing Mechanisms Generator Control Mechanisms PITCH CONTROL Pitch control is the technology used to control the angle of the blades in a wind turbine. The pitch control system is made up of electric motors and gears , or hydraulic cylinders and a power supply system. The pitch angle control is a closed loop drive system and the controller calculates the required pitch angle from a set of conditions, such as wind speed, generator speed and power production .

55. YAW CONTROL For the places with the prevailing wind in one direction, the design of wind turbine is simple i.e., the rotor can be fixed with the swept area perpendicular to wind direction . It is called YAW FIXED machine Most of the machines are YAW ACTIVE , i.e., when the wind direction changes, the YAW motor rotates the turbine (in the vertical axis) to face the rotor blades in to the wind. It makes the area swept by the rotor blade perpendicular to the direction of the wind . In small wind turbine generators, the YAW control is realized by Tail Vane

56. TRANSMISSION & GEARING Large WTG’s operating at the rated capacity (pitch controlled), generally rotates at 40 to 50 revolutions per minute (rpm). But for optimum output, the generator mandates much higher rate of rotation such as 1500 rpm for 50Hz frequency and 1800 rpm for 60Hz frequency. Hence, transmission system with gearing is necessary to increase the slow rate of tuning of rotor shaft into high speed rotation at the generator shaft. Fixed ratio gears are recommended for top mounted WTG, because of their high efficiency, known cost and minimum system risk.

57. GENERATOR Generator is a device that produces electricity when mechanical energy is given as the input. As per the output, the wind aero generators are classified as, Small (up to 1 kW) – Permanent Magnet DC generators Medium (up to 200 kW) – Permanent Magnet DC generators, IG, Syn. Generator Large ( 200kW – mega W) – Induction Generator, Synchronous Generator Schemes for Electric Power Generation Constant Speed Constant Frequency system (CSCF) Variable speed Constant Frequency system (VSCF) Variable speed Variable Frequency system (VSVF)

58. BLOCK DIAGRAM OF WECS

59. CONTROLLER Orientation of WTG rotor in to the wind (YAW Control) Start-up and cut in of the equipment Power control of the rotor by varying the pitch of the blades (Pitch control) Generator output monitoring – status, storage, data computation Shutdown and cot-out owing to malfunction or very high winds Protection for generator, the utility accepting the power and the prime mover Auxiliary and /or emergency power

60. TOWER The types of tower, The reinforced cement concrete tower The pole tower The built-up shell tube tower (widely used) The truss tower (simple and low cost) The towers provide mechanical strength to hold the turbine , transmission and generator assembly at the top It also houses the controls at the base of the tower. FOUNDATION The foundation supports the entire wind turbine and make sure that it is well fixed onto the ground or the roof for small household wind turbines. This is usually consists of a solid concrete assembly around the tower to maintain its structural integrity.

61. TYPES OF WIND TURBINE Wind turbines are generally classified into two types, Horizontal axis wind turbines Vertical axis wind turbines

62. HORIZONTAL AXIS WIND TURBINES It is the most common wind turbine design. A horizontal axis machine has its blades rotating on an axis parallel to the ground. Depending on the number of blades, horizontal axis wind turbines are classified as, Single bladed HAT Two bladed HAT Multi bladed HAT Single bladed designs are not very popular due to problems in balancing and visual acceptability. Two bladed rotors also have these drawbacks, but to a lesser extent. Most of the present commercial turbines used for electricity generation have three blades.

63. Single Bladed HAT Two Bladed HAT Multi Bladed HAT

64. Advantages of Horizontal Axis wind turbines Variable blade pitch of the HAT blades gives the optimum angle of attack which makes the HAT to collects the maximum amount of wind energy for day and season time. The tall tower base allows access to stronger wind in sites with wind shear. Disadvantages of Horizontal Axis wind turbines HAWT’s require an additional yaw control mechanism to turn the blades toward the wind. HAWT’s have difficulty operating in near ground turbulent winds. The tall towers and blades up to 90 meters long are difficult to transport. Transportation can now cost 20% of equipment costs.

65. OCEAN ENERGY From the oceans we can harvest the energy by three methods, Ocean Thermal Energy Conversion Wave Energy Tidal Energy

66. OCEAN THERMAL ENERGY CONVERSION The ocean is the world’s largest solar collector. In tropical seas, temperature differences of about 20˚−25˚C may occur between the warm solar-absorbing near-surface water and the cooler 500–1000m depth ‘deep’ water Subject to the laws of thermodynamics, heat engines can operate from this temperature difference. The term ocean thermal energy conversion (OTEC) refers to the conversion of some of this thermal energy into useful work for electricity generation.

67. OTEC produces electricity from the natural thermal gradient of the ocean. The heat stored in warm surface water is used to generate steam that drives a turbine. In the evaporator, the heat from the warm sea water is transferred to the working fluid which is Ammonia. (Ammonia is used as the working fluid because of its low boiling point) The ammonia vapor from the evaporator turns a turbine, which drives a generator to generate electricity. The vapor is then condensed by the cold water and cycled back through the system.

68. OCEAN THERMAL ENERGY CONVERSION (Open Cycle)

69. WAVE ENERGY Waves are formed by the transfer of energy from the wind to the ocean surface . Wave energy has long been considered one of the most promising renewable technologies. The size of the waves will depend on three factors : Strength of the winds Amount of time that the winds blows The distance (fetch) over which it blows

70. The distinctive advantages of wave power are: The large energy fluxes Available and the predictability of wave conditions over periods of days. Waves are created by wind, and effectively store the energy for transmission over great distances. Wave height is determined by the wind speed, the fetch, depth and the topography of the sea floor. The common measure for wave power levels is the average annual power per metre of the wave crest width parallel to the shoreline.

71. TIDAL ENERGY The influences of the gravitational forces of the earth, sun and the moon become very strong and cause millions of gallons of water to move or flow towards the shore creating high tides and low tides. The level of water in the large oceans of the Earth rises and falls according to predictable patterns . The change in height between successive high and low tides is the range. This varies between about 0.5m in general and about 10m at particular sites near continental land masses. The movement of the water produces tidal currents, which may reach speeds of approximately 5m/s in coastal and inter-island channels. The power of tidal currents may be harnessed in a manner similar to wind power; this is also called „tidal stream power’.

72. The energy available from tidal power plant barrage that can be built to harness the tides is dependent on the potential energy contained in the volume of water which can be represented as follows. where, M = Mass of water g = Acceleration due to gravity (9.81 m/s2 at the earth's surface) h = Height of the tide.

73. OPERATION When a tidal basin (large reservoir) is available near the sea, a tidal barrage with sluice gates and Turbine Tunnel shall be constructed to realize a TIDAL POWER PLANT During the time of High Tide , the sluice Gates are kept OPEN and the sea water enters the tidal basin through the TURBINE TUNNEL rotating the turbine connected to the generator which generates electrical energy. Flowing water always carries kinetic energy, which is harvested to generate electrical energy When the water level in the Tidal Basin reaches the High Tide Level, the sluice gates will be closed. During the time of Low Tide , the sluice Gates will be opened and the water from the Tidal basin will flow with pressure to the sea through the TURBINE TUNNEL, which rotates the turbine to generate electrical energy. In all in a TIDAL POWER PLANT, the water currents flowing in and out of the tidal basins are exploited to turn mechanical devices in order to produce electricity.

74. ADVANTAGE OF TIDAL POWER PLANT: Highly predictable compared to solar , wind and wave energy. Regularity of the tides with immense energy potential helps make tidal energy development attractive. DISADVANTAGES OF TIDAL POWER The mismatch of the principal solar driven periods. So that optimum tidal power generation is not in phase with demand. The changing tidal range and flow over a two-week period, producing changing power production. The requirement for large water volume flow at low head, necessitating many specially constructed turbines set in parallel. The very large capital costs of most potential installations. The location of sites with large range may be distant from the demand for power. Potential ecological harm and disruption to extensive estuaries or marine regions.

75. BIOMASS POWER PLANT Biomass is organic material that comes from plants and animals, and it is a renewable source of energy Biomass contains stored energy from the sun. Plants absorb the sun's energy in a process called photosynthesis. When biomass is burned, the chemical energy in biomass is released as heat. Biomass is available in three basic forms of solid, liquid and gas.

76. Solid Biomass Agricultural residues like straw, grasses, seeds, roots, dried plants, nut shells and crop residues like rice husk. etc. Municipal solid waste from household rubbish and garbage. Animal waste such as dried slurry and manure. Plant and Wood waste (residues) such as trees, shrubs, sawdust, pellets, chips and waste wood. Liquid Biomass Biodiesel distilled from vegetable oils and animal fats. Vegetable oils from sunflower, rapeseeds or other vegetable oils. Methanol, ethanol and alcohol based fuels fermented from corn, grain and other plant matter.

77. Biogas Methane from decomposing plants, animals and manure Biogas generated from rotting rubbish in landfills Hydrogen from batteries and fuel cells Synthesis gas blended from carbon monoxide and hydrogen Natural gas from fossil fuels.

78. BIOMASS POWER PLANT

79. Crop residues and woody biomass from trees are used as feedstock for the Biomass based power generation system. Currently, wood-based systems are available, and designs using other low-density biomass are under development. The feedstock is first dried in the processing and drying unit. The feedstock is dried for better combustion. In the combustion chamber, the burner is used to fire the biomass. Heat energy is generated at the chamber and liquid is pumped through the suitable pumping system. Steam will be generated and it operates steam turbine. Generator which is connected with the turbine will produce electricity and it is given to the local distributing system.

80. Different methods of ENERGY extraction from biomass Anaerobic Digestion Anaerobic Digestion is a process by which microorganism’s breakdown biodegradable material in the absence of oxygen. The process is used to convert industrial waste to fuel. (For example: Methane)   Pyrolysis Pyrolysis  is the thermal decomposition of materials at elevated temperatures in an inert atmosphere (in the absence of oxygen) Gasification Gasification is a process that exposes a solid fuel to high temperatures and limited oxygen, to produce a gaseous fuel.

81. FUEL CELL A fuel cell is a device that converts chemical potential energy (energy stored in molecular bonds) into electrical energy. (or) A fuel cell is a device that generates electricity by a chemical reaction.

82. COMPONENTS OF FUEL CELL Two electrodes namely the anode and cathode. An electrolyte which carries electrically charged particles from one electrode to the other A catalyst which speeds the reactions at the electrodes.  FUEL --- Hydrogen and Oxygen A single fuel cell generates a small quantity of direct current (DC) electricity. In practice, many fuel cells are usually assembled into a stack.

83. TYPES OF FUEL CELL PAFC - Phosphoric Acid Fuel Cell SOFC - Solid Oxide Fuel Cell MCFC - Molten Carbonate Fuel Cell PEMFC - Proton Exchange Membrane AFC - Alkaline Fuel Cell

84. PHOSPHORIC ACID FUEL CELL AT ANODE: Hydrogen enters the fuel cell at anode, where the chemical reaction in the electrode strips the hydrogen atoms in to hydrogen ion and electrons Anode reaction: 2H 2 (g) → 4H +  + 4e‾ ELECTROLYTE: Phosphoric (mineral) acid functions as the electrolyte Phosphoric acid allows only the positively charged ions (or) protons to pass through It will not allow the electron to flow through it. This makes the electrons to flow through the external circuit. AT CATHODE: Oxygen enters the fuel cell at cathode. It combines with electrons returning from the electrical circuit and hydrogen ions that have traveled through the electrolyte from the anode. It gives out water and it drains from the cell. Cathode reaction: O 2 (g) + 4H +  + 4e‾ → 2H 2 O OVERALL REACTION Overall cell reaction: 2 H 2  + O 2  → 2H 2 O

85. PROTON EXCHANGE MEMBRANE FUEL CELL PEMFC uses porous carbon electrodes with platinum catalyst Perfluorosulphonic acid ( Nafion ) is used as electrolyte polymer AT ANODE: The platinum catalysts cause the hydrogen to split in to hydrogen ions (protons) and electrons. The polymer electrolyte membrane allows only the protons to pass through that to the cathode It forces the electron to flow through the external circuit AT CATHODE: OVERALL REACTION

86. Advantages of Fuel Cell Fuel cells have high power density Low weight, Compactness Fuel cells have a higher efficiency than diesel or gas engines. The maintenance of fuel cells is simple since there are few moving parts in the system. Fuel cells operate silently, compared to internal combustion engines; hence it is ideally suited for use within buildings such as hospitals. Fuel cells eliminate pollution as water is the only by-product of the fuel cell. Using fuel cells eliminates greenhouse gases over the whole cycle. As the hydrogen can be produced anywhere where there is water and can be used as a power source where the grid extension is not possible.

87. Applications of Fuel Cell Distributed or Standalone power generation system Automotive power generation Portable power generation systems

88. Thank You all