Energy is the ability to do work and work is the transfer of energy from one form to another. In
practical terms, energy is what we use to manipulate the world around us, whether by exciting
our muscles, by using electricity, or by using mechanical devices such as automobiles. Energy
comes in different forms - heat (thermal), light (radiant), mechanical, electrical, chemical, and
nuclear energy.
The document discusses the basics of various forms of energy including electrical, thermal, and potential energy. It defines key terms like voltage, current, resistance, power factor, and electricity tariffs. It also covers thermal energy concepts such as temperature, pressure, heat, and different fuel types and their energy contents. The document provides examples to illustrate energy consumption calculations for electrical devices.
This document provides an overview of different types of energy sources and electrical power generation methods. It discusses various thermal and non-thermal power generation schemes including coal, diesel, nuclear, solar, hydro, tidal, and wind power. For each method, a brief description is given of the generation process. The document also covers electrical circuit concepts such as resistance, conductance, Ohm's law, series and parallel circuits, and inductance.
Most electricity in the US is produced using steam turbines in power plants. Coal is commonly burned to heat water and produce steam, which spins the turbine and generates electricity. This electricity is sent through transformers to increase the voltage for long distance transmission on power lines before being stepped down for local distribution and use in homes and businesses. Implementing a "smart grid" that uses sensors and two-way communication could help modernize the aging electrical infrastructure to reduce waste and better incorporate renewable energy sources.
This paper describes the design of power electronic converter circuit and simulating the power electronic converter circuit using Matlab/Simulink for induction heating equipment. The circuit designed has the load as induction coil and high frequency electricity is required to heat the workpiece placed within the induction coil. The output power of the load coil is varied by changing the frequency of the inverter.
14 9737 lightning paper id 0005 edit septianIAESIJEECS
Study the impacts of lightning-induced transient overvoltage on a hybrid PV-Wind system has been addressed in this work. Overvoltage that is generated due to lightning stroke travels along the system where it can be very harmful to the expensive equipment of the system such as PV models, inverters, charge controllers, batteries, transformers, and generator etc. The simulation model of a system has been completed by using PSCAD/EMTDC software. The system comprises of 2 MW PV farm, battery system, 2.1 MW wind farm and loads which are all connected to the common AC bus and then to the utility grid through an interfacing transformer. Lightning current is generated by using the double exponential function, from the simulation results, when the lightning current is injected to the AC and DC sides of PV system, the transient current and voltage have appeared at different points of the hybrid system. The results were obtained for 8/20 μs and 10/350 μs standards lightning waveforms with current magnitude of 100 kA.
Uss module 4 chpt 5 Sources of ElectricityBetsy Eng
This document discusses different sources of electricity. It begins by describing how electricity is generated in power stations using fossil fuels like coal, gas and oil, as well as nuclear power. The electricity is then transmitted through high voltage transmission lines and transformers are used to step down the voltage for safe distribution and use. Transformers are described as coils of wire that can increase or decrease voltage. The document also discusses batteries as a portable source of electricity, where chemical energy is converted to electrical energy. Batteries are important for powering devices like phones and laptops.
The document provides an overview of India's power system, including:
1. It discusses the key components of a power system including generation, transmission, distribution, and utilization. Electricity is generated mostly through thermal, hydro, and nuclear means.
2. The document then covers electricity basics like voltage, current, resistance, power, frequency and units. It also explains the differences between direct current and alternating current power systems.
3. Reactive power, power factor correction, and three-phase systems are also summarized. Maintaining proper reactive power and power factor is important for power transmission and distribution.
The document provides information about various types of energy including:
- The sun is the ultimate source of energy for things like beef which comes from cows that eat grass powered by photosynthesis.
- There are 9 main types of energy including heat, kinetic, nuclear, sound, light, chemical, electrical, gravitational potential, and elastic potential.
- Energy can change forms through processes like conduction, convection, and radiation.
- Efficiency measures how much useful energy is obtained from the total energy input.
- There is a difference between renewable energy sources like solar and wood versus non-renewable fossil fuels like coal, oil and gas.
The document discusses the basics of various forms of energy including electrical, thermal, and potential energy. It defines key terms like voltage, current, resistance, power factor, and electricity tariffs. It also covers thermal energy concepts such as temperature, pressure, heat, and different fuel types and their energy contents. The document provides examples to illustrate energy consumption calculations for electrical devices.
This document provides an overview of different types of energy sources and electrical power generation methods. It discusses various thermal and non-thermal power generation schemes including coal, diesel, nuclear, solar, hydro, tidal, and wind power. For each method, a brief description is given of the generation process. The document also covers electrical circuit concepts such as resistance, conductance, Ohm's law, series and parallel circuits, and inductance.
Most electricity in the US is produced using steam turbines in power plants. Coal is commonly burned to heat water and produce steam, which spins the turbine and generates electricity. This electricity is sent through transformers to increase the voltage for long distance transmission on power lines before being stepped down for local distribution and use in homes and businesses. Implementing a "smart grid" that uses sensors and two-way communication could help modernize the aging electrical infrastructure to reduce waste and better incorporate renewable energy sources.
This paper describes the design of power electronic converter circuit and simulating the power electronic converter circuit using Matlab/Simulink for induction heating equipment. The circuit designed has the load as induction coil and high frequency electricity is required to heat the workpiece placed within the induction coil. The output power of the load coil is varied by changing the frequency of the inverter.
14 9737 lightning paper id 0005 edit septianIAESIJEECS
Study the impacts of lightning-induced transient overvoltage on a hybrid PV-Wind system has been addressed in this work. Overvoltage that is generated due to lightning stroke travels along the system where it can be very harmful to the expensive equipment of the system such as PV models, inverters, charge controllers, batteries, transformers, and generator etc. The simulation model of a system has been completed by using PSCAD/EMTDC software. The system comprises of 2 MW PV farm, battery system, 2.1 MW wind farm and loads which are all connected to the common AC bus and then to the utility grid through an interfacing transformer. Lightning current is generated by using the double exponential function, from the simulation results, when the lightning current is injected to the AC and DC sides of PV system, the transient current and voltage have appeared at different points of the hybrid system. The results were obtained for 8/20 μs and 10/350 μs standards lightning waveforms with current magnitude of 100 kA.
Uss module 4 chpt 5 Sources of ElectricityBetsy Eng
This document discusses different sources of electricity. It begins by describing how electricity is generated in power stations using fossil fuels like coal, gas and oil, as well as nuclear power. The electricity is then transmitted through high voltage transmission lines and transformers are used to step down the voltage for safe distribution and use. Transformers are described as coils of wire that can increase or decrease voltage. The document also discusses batteries as a portable source of electricity, where chemical energy is converted to electrical energy. Batteries are important for powering devices like phones and laptops.
The document provides an overview of India's power system, including:
1. It discusses the key components of a power system including generation, transmission, distribution, and utilization. Electricity is generated mostly through thermal, hydro, and nuclear means.
2. The document then covers electricity basics like voltage, current, resistance, power, frequency and units. It also explains the differences between direct current and alternating current power systems.
3. Reactive power, power factor correction, and three-phase systems are also summarized. Maintaining proper reactive power and power factor is important for power transmission and distribution.
The document provides information about various types of energy including:
- The sun is the ultimate source of energy for things like beef which comes from cows that eat grass powered by photosynthesis.
- There are 9 main types of energy including heat, kinetic, nuclear, sound, light, chemical, electrical, gravitational potential, and elastic potential.
- Energy can change forms through processes like conduction, convection, and radiation.
- Efficiency measures how much useful energy is obtained from the total energy input.
- There is a difference between renewable energy sources like solar and wood versus non-renewable fossil fuels like coal, oil and gas.
Analysis of Voltage and Current Variations in Hybrid Power SystemIJRST Journal
In this paper, a detailed dynamic model and simulation of a solar cell/wind turbine/fuel cell hybrid power system is Developed using a novel topology to complement each other and to alleviate the effects of environmental variations. Comparing with the nuclear energy and thermal power, the renewable energy is inexhaustible and has non-pollution Characteristics. Here Ultra-capacitors are used in power applications requiring short duration peak power. The voltage variation at the output is found to be within the acceptable range. The output fluctuations of the wind turbine varying with wind speed and the solar cell varying with both environmental temperature and sun radiation are reduced using a fuel cell. Therefore, this system can tolerate the rapid changes in load and environmental conditions, and suppress the effects of these fluctuations on the equipment side voltage. The proposed system can be used for off-grid power generation in non interconnected areas or remote isolated communities. Modeling and simulations are conducted using MATLAB/Simulink software packages to verify the effectiveness of the proposed system. The results show that the proposed hybrid power system can tolerate the rapid changes in natural conditions and suppress the effects of these fluctuations on the voltage within the acceptable range.
This document discusses different types of energy, including renewable and non-renewable energy sources. It describes how electricity is a secondary energy source produced from primary sources. It also explains key components of an electric power system, including Ohm's Law which relates current, voltage and resistance in a circuit. Power-law relationships are also covered, along with how power can be calculated using current and voltage based on the power rule.
Report on energy harvesting through mechanical vibrationEr Shambhu Chauhan
This document discusses energy harvesting through mechanical vibration. It begins with an introduction to energy harvesting, noting its importance for powering wireless sensors and recharging batteries. Mechanical vibration is identified as a source of energy that can be harvested. Common techniques for harvesting vibration energy are then described, including electromagnetic, electrostatic, piezoelectric, and magnetostrictive methods. Two specific examples are provided: a mechanical motion rectifier that converts oscillating vibration to rotation, and a triboelectric nanogenerator that uses a triple-cantilever design. The document concludes with discussing future work in energy harvesting.
1. The document describes an experiment to generate electricity using magnets and a brushless fan. The fan coil is connected to an LED via a breadboard to test electricity generation.
2. Testing showed that reducing the number of blades and magnets increased fan speed, and thus increased voltage output. Using two magnets with opposite poles produced more stable rotation and higher voltage than a single magnet.
3. The experiment demonstrates that a brushless fan can act as a generator through magnetic repulsion on its blades, producing enough voltage to light an LED. Adding more magnets or reducing mass improved rotational speed and electricity generation.
This document provides information about a technology unit on electricity for 14-year-old students. The unit aims to introduce students to electricity, its effects, and environmental impact. Over the course of a term, students will learn about electric circuits and components, build basic circuits in workshops and simulations, and understand electrical safety and sustainability. Assessment will be built into exercises and practices throughout the unit.
A New Simulation Approach of 3-Φ Transformer-less Grid Connected PV Inverter ...IRJET Journal
1) The document describes a simulation of a 3-phase grid-connected photovoltaic inverter system using hysteresis current control.
2) It uses a two-stage conversion process with a boost converter to maximize solar panel output and regulate the DC bus voltage, followed by an inverter with hysteresis current control to generate AC power for the grid.
3) Simulation results show the inverter is able to generate sinusoidal voltage and current waveforms that are synchronized to the grid, with total harmonic distortion below 5% using hysteresis current control.
This document describes an elective on energy harvesting that will discuss harnessing renewable energy from the environment, including an overview of energy harvesting, applications, and a hands-on activity where students will characterize solar panels and use the energy to power loads like LEDs, motors, and buzzers. Students will also design a scenario to power a 3 room apartment using solar energy under constraints set by the owner.
This document discusses analyzing electrical energy and power. It defines electrical energy as the energy released when electric charges flow through any two points in an electric circuit. Electric power is defined as the rate at which electrical energy is released. Formulas are provided for calculating electrical energy, power, current, and resistance in various circuits. Examples problems are given and solved for finding current, energy usage, and cost based on power ratings and time. The concepts of power rating, energy consumption, and energy efficiency are compared for different electrical appliances. Ways to increase energy efficiency such as using efficient lighting and appliances and eliminating wasted energy are described.
This document describes the simulation of an induction melting furnace power supply using MATLAB. It begins with an introduction to induction furnaces and their components. It then describes the proposed control method to provide constant output power using a controlled three-phase rectifier and IGBT switches in place of thyristors. The document outlines the simulation of the power supply circuits including the source, rectifier, booster circuit, inverter, and induction heating load. It presents the specification of an actual induction furnace and calculations for the furnace parameters. Waveforms are simulated and compared to the actual system. The conclusion states that the IGBT-based control panel for induction melting furnace was designed and simulated in MATLAB.
1. Generators produce electrical energy from mechanical energy. Thermal generators use steam from burning fossil fuels to rotate turbines, which turn generators. Hydroelectric generators use water flowing through dams to rotate turbines connected to generators.
2. Transformers are used to change the voltage of alternating current for transmission and distribution of electrical power. Step-up transformers increase voltage for transmission, while step-down transformers reduce voltage for distribution and use.
3. Electrical power is transmitted through a national grid network via high voltage circuits connecting power stations. It is then distributed to consumers through a system of transformer stations, switch zones, main substations, and branch substations.
Performance Investigation of Grid Connected Photovoltaic System Modelling Bas...IJECEIAES
Photovoltaic (PV) systems are normally modeled by employing accurate equations dealing with a behavior the PV system. This model has Characteristic of PV array cells, which are influenced by both irradiation and temperature variations. Grid-connected PV system is considered as electricity generated solar cell system which is connected to the grid utilities. This paper characterizes an exhibiting and simulating of PV system that executed with MATLAB /Simulink. The impact of solar irradiances as well as ambient temperature performances of PV models is investigated and noted that a lower temperature provides maximum power higher so that the open circuit voltage is larger. Furthermore, if the temperature is low, then a considerably short circuit current is low too.
1) The document discusses measuring electrical power, energy, and cost. Power (P) is measured in Watts and can be calculated using P=VI, P=I2R, or P=V2/R. Energy (E) is measured in Joules and can be calculated using E=VIt, E=I2Rt, or E=V2t/R.
2) Electrical energy consumed by homes is measured in kilowatt-hours (kWh). As an example, a 1.5kW heater used for 2 hours would consume 3kWh or 1.08x108Joules of energy.
3) The document also discusses safety features like circuit
The document discusses different forms of energy including kinetic energy, potential energy, nuclear energy, electrical energy, chemical energy, gravitational energy, sound energy, mechanical energy, thermal energy, and energy transformation. Kinetic energy is the energy of motion, potential energy is stored energy, nuclear energy comes from splitting atoms, electrical energy comes from the motion and position of electrical charges, and chemical energy is stored in molecular arrangements. Gravitational energy comes from mass and its position in a gravitational field, sound energy comes from vibrations, and mechanical energy is the sum of potential and kinetic energy. Thermal energy comes from molecular motion and temperature, and energy transformation is the change between different forms of energy.
Vibration Energy Harvesting in Action: Real World Case StudiesKarim El-Rayes
This is the slides for my talk at Sensors Expo & Conference 2018 in San Jose, California, on commercial and research applications of vibrations energy harvesting in the fields of medical implants, wearables, structural health monitoring, green buildings and many other. #Sensors18
This document provides an overview of different forms of energy including kinetic energy, potential energy, and thermal energy. It discusses key concepts like the principle of conservation of energy and how energy is converted from one form to another but cannot be created or destroyed. Examples are given of energy conversions that occur during activities like throwing a ball, shooting an arrow, and lighting a light bulb. The document also defines power as the rate of energy transfer and provides the formula for calculating power given the energy and the time taken. An example calculation of power is shown.
1) The document discusses micro-vibrational energy harvesting using piezoelectric transducers. It notes that piezoelectric transducers have the potential to power wireless electronics by harvesting ambient vibrational energy.
2) A cantilever beam design with piezoelectric plates bonded to the beam and a tip mass is proposed as the most effective configuration for capturing vibrational energy.
3) The document also examines energy harvesting circuits, noting the importance of matching the circuit design to the application to optimize power efficiency and output performance.
In modern days, the use of energy consumption increasing very rapidly. Fossil fuels are finite and environmentally costly. Sustainable, environmentally benign energy can be derived from nuclear fission or captured from ambient sources. Large-scale ambient energy (eg. solar, wind and tide), is widely available and large-scale technologies are being developed to efficiently capture it. At the other end of the scale, there are small amounts of ‘wasted’ energy that could be useful if captured. Recovering even a fraction of this energy would have a significant economic and environmental impact. This is where energy harvesting (EH) comes in.
This document discusses electrical energy generation, transmission, and usage. It covers topics such as how generators convert mechanical energy to electrical energy using various fuel sources. Transformers are described as devices that change the voltage of alternating current by varying the number of turns in primary and secondary coils. Electrical power flows from power stations through transmission networks via step-up and step-down transformers before reaching consumers. The document also discusses safety features like fuses, circuit breakers, and earth wires in home wiring systems.
The document provides information about different types of energy sources and power stations. It discusses various forms of energy including mechanical, electrical, chemical and nuclear energy. It describes different power generation methods like coal, nuclear, hydroelectric, solar, wind, biomass, geothermal and fusion energy power stations. For each power station type, it outlines the basic process and discusses advantages and disadvantages. The document also covers energy units, energy consumption in Spain and its dependence on fossil fuels for electricity production.
Energy exists in various forms including potential, kinetic, chemical, thermal, electrical, nuclear, and motion. Potential energy is stored energy due to position or composition, like energy stored in compressed springs or chemical bonds. Kinetic energy is energy in motion, like radiant, thermal, or electrical energy. Energy can be converted from one form to another, though conversions reduce overall efficiency. High-grade energy like electricity is concentrated and can do large amounts of work, while low-grade heat disperses and does less concentrated work. Electrical energy can be direct current, alternating current, measured in volts and amps, and involves concepts like resistance, power, and power factor relating to efficiency.
This document provides an introduction to electricity and electrical systems. It describes the basics of electricity, including electric charge, conductivity, electric potential, electric fields, static electricity, current, potential difference, resistance, and electric circuits. It then discusses different power generation systems, including public utilities, plant generation systems, stand-by generators, emergency power sources, and cogeneration systems. The goal is to help operators better understand the characteristics of electricity and components of electric circuits to feel more comfortable working with electrical equipment.
Analysis of Voltage and Current Variations in Hybrid Power SystemIJRST Journal
In this paper, a detailed dynamic model and simulation of a solar cell/wind turbine/fuel cell hybrid power system is Developed using a novel topology to complement each other and to alleviate the effects of environmental variations. Comparing with the nuclear energy and thermal power, the renewable energy is inexhaustible and has non-pollution Characteristics. Here Ultra-capacitors are used in power applications requiring short duration peak power. The voltage variation at the output is found to be within the acceptable range. The output fluctuations of the wind turbine varying with wind speed and the solar cell varying with both environmental temperature and sun radiation are reduced using a fuel cell. Therefore, this system can tolerate the rapid changes in load and environmental conditions, and suppress the effects of these fluctuations on the equipment side voltage. The proposed system can be used for off-grid power generation in non interconnected areas or remote isolated communities. Modeling and simulations are conducted using MATLAB/Simulink software packages to verify the effectiveness of the proposed system. The results show that the proposed hybrid power system can tolerate the rapid changes in natural conditions and suppress the effects of these fluctuations on the voltage within the acceptable range.
This document discusses different types of energy, including renewable and non-renewable energy sources. It describes how electricity is a secondary energy source produced from primary sources. It also explains key components of an electric power system, including Ohm's Law which relates current, voltage and resistance in a circuit. Power-law relationships are also covered, along with how power can be calculated using current and voltage based on the power rule.
Report on energy harvesting through mechanical vibrationEr Shambhu Chauhan
This document discusses energy harvesting through mechanical vibration. It begins with an introduction to energy harvesting, noting its importance for powering wireless sensors and recharging batteries. Mechanical vibration is identified as a source of energy that can be harvested. Common techniques for harvesting vibration energy are then described, including electromagnetic, electrostatic, piezoelectric, and magnetostrictive methods. Two specific examples are provided: a mechanical motion rectifier that converts oscillating vibration to rotation, and a triboelectric nanogenerator that uses a triple-cantilever design. The document concludes with discussing future work in energy harvesting.
1. The document describes an experiment to generate electricity using magnets and a brushless fan. The fan coil is connected to an LED via a breadboard to test electricity generation.
2. Testing showed that reducing the number of blades and magnets increased fan speed, and thus increased voltage output. Using two magnets with opposite poles produced more stable rotation and higher voltage than a single magnet.
3. The experiment demonstrates that a brushless fan can act as a generator through magnetic repulsion on its blades, producing enough voltage to light an LED. Adding more magnets or reducing mass improved rotational speed and electricity generation.
This document provides information about a technology unit on electricity for 14-year-old students. The unit aims to introduce students to electricity, its effects, and environmental impact. Over the course of a term, students will learn about electric circuits and components, build basic circuits in workshops and simulations, and understand electrical safety and sustainability. Assessment will be built into exercises and practices throughout the unit.
A New Simulation Approach of 3-Φ Transformer-less Grid Connected PV Inverter ...IRJET Journal
1) The document describes a simulation of a 3-phase grid-connected photovoltaic inverter system using hysteresis current control.
2) It uses a two-stage conversion process with a boost converter to maximize solar panel output and regulate the DC bus voltage, followed by an inverter with hysteresis current control to generate AC power for the grid.
3) Simulation results show the inverter is able to generate sinusoidal voltage and current waveforms that are synchronized to the grid, with total harmonic distortion below 5% using hysteresis current control.
This document describes an elective on energy harvesting that will discuss harnessing renewable energy from the environment, including an overview of energy harvesting, applications, and a hands-on activity where students will characterize solar panels and use the energy to power loads like LEDs, motors, and buzzers. Students will also design a scenario to power a 3 room apartment using solar energy under constraints set by the owner.
This document discusses analyzing electrical energy and power. It defines electrical energy as the energy released when electric charges flow through any two points in an electric circuit. Electric power is defined as the rate at which electrical energy is released. Formulas are provided for calculating electrical energy, power, current, and resistance in various circuits. Examples problems are given and solved for finding current, energy usage, and cost based on power ratings and time. The concepts of power rating, energy consumption, and energy efficiency are compared for different electrical appliances. Ways to increase energy efficiency such as using efficient lighting and appliances and eliminating wasted energy are described.
This document describes the simulation of an induction melting furnace power supply using MATLAB. It begins with an introduction to induction furnaces and their components. It then describes the proposed control method to provide constant output power using a controlled three-phase rectifier and IGBT switches in place of thyristors. The document outlines the simulation of the power supply circuits including the source, rectifier, booster circuit, inverter, and induction heating load. It presents the specification of an actual induction furnace and calculations for the furnace parameters. Waveforms are simulated and compared to the actual system. The conclusion states that the IGBT-based control panel for induction melting furnace was designed and simulated in MATLAB.
1. Generators produce electrical energy from mechanical energy. Thermal generators use steam from burning fossil fuels to rotate turbines, which turn generators. Hydroelectric generators use water flowing through dams to rotate turbines connected to generators.
2. Transformers are used to change the voltage of alternating current for transmission and distribution of electrical power. Step-up transformers increase voltage for transmission, while step-down transformers reduce voltage for distribution and use.
3. Electrical power is transmitted through a national grid network via high voltage circuits connecting power stations. It is then distributed to consumers through a system of transformer stations, switch zones, main substations, and branch substations.
Performance Investigation of Grid Connected Photovoltaic System Modelling Bas...IJECEIAES
Photovoltaic (PV) systems are normally modeled by employing accurate equations dealing with a behavior the PV system. This model has Characteristic of PV array cells, which are influenced by both irradiation and temperature variations. Grid-connected PV system is considered as electricity generated solar cell system which is connected to the grid utilities. This paper characterizes an exhibiting and simulating of PV system that executed with MATLAB /Simulink. The impact of solar irradiances as well as ambient temperature performances of PV models is investigated and noted that a lower temperature provides maximum power higher so that the open circuit voltage is larger. Furthermore, if the temperature is low, then a considerably short circuit current is low too.
1) The document discusses measuring electrical power, energy, and cost. Power (P) is measured in Watts and can be calculated using P=VI, P=I2R, or P=V2/R. Energy (E) is measured in Joules and can be calculated using E=VIt, E=I2Rt, or E=V2t/R.
2) Electrical energy consumed by homes is measured in kilowatt-hours (kWh). As an example, a 1.5kW heater used for 2 hours would consume 3kWh or 1.08x108Joules of energy.
3) The document also discusses safety features like circuit
The document discusses different forms of energy including kinetic energy, potential energy, nuclear energy, electrical energy, chemical energy, gravitational energy, sound energy, mechanical energy, thermal energy, and energy transformation. Kinetic energy is the energy of motion, potential energy is stored energy, nuclear energy comes from splitting atoms, electrical energy comes from the motion and position of electrical charges, and chemical energy is stored in molecular arrangements. Gravitational energy comes from mass and its position in a gravitational field, sound energy comes from vibrations, and mechanical energy is the sum of potential and kinetic energy. Thermal energy comes from molecular motion and temperature, and energy transformation is the change between different forms of energy.
Vibration Energy Harvesting in Action: Real World Case StudiesKarim El-Rayes
This is the slides for my talk at Sensors Expo & Conference 2018 in San Jose, California, on commercial and research applications of vibrations energy harvesting in the fields of medical implants, wearables, structural health monitoring, green buildings and many other. #Sensors18
This document provides an overview of different forms of energy including kinetic energy, potential energy, and thermal energy. It discusses key concepts like the principle of conservation of energy and how energy is converted from one form to another but cannot be created or destroyed. Examples are given of energy conversions that occur during activities like throwing a ball, shooting an arrow, and lighting a light bulb. The document also defines power as the rate of energy transfer and provides the formula for calculating power given the energy and the time taken. An example calculation of power is shown.
1) The document discusses micro-vibrational energy harvesting using piezoelectric transducers. It notes that piezoelectric transducers have the potential to power wireless electronics by harvesting ambient vibrational energy.
2) A cantilever beam design with piezoelectric plates bonded to the beam and a tip mass is proposed as the most effective configuration for capturing vibrational energy.
3) The document also examines energy harvesting circuits, noting the importance of matching the circuit design to the application to optimize power efficiency and output performance.
In modern days, the use of energy consumption increasing very rapidly. Fossil fuels are finite and environmentally costly. Sustainable, environmentally benign energy can be derived from nuclear fission or captured from ambient sources. Large-scale ambient energy (eg. solar, wind and tide), is widely available and large-scale technologies are being developed to efficiently capture it. At the other end of the scale, there are small amounts of ‘wasted’ energy that could be useful if captured. Recovering even a fraction of this energy would have a significant economic and environmental impact. This is where energy harvesting (EH) comes in.
This document discusses electrical energy generation, transmission, and usage. It covers topics such as how generators convert mechanical energy to electrical energy using various fuel sources. Transformers are described as devices that change the voltage of alternating current by varying the number of turns in primary and secondary coils. Electrical power flows from power stations through transmission networks via step-up and step-down transformers before reaching consumers. The document also discusses safety features like fuses, circuit breakers, and earth wires in home wiring systems.
The document provides information about different types of energy sources and power stations. It discusses various forms of energy including mechanical, electrical, chemical and nuclear energy. It describes different power generation methods like coal, nuclear, hydroelectric, solar, wind, biomass, geothermal and fusion energy power stations. For each power station type, it outlines the basic process and discusses advantages and disadvantages. The document also covers energy units, energy consumption in Spain and its dependence on fossil fuels for electricity production.
Energy exists in various forms including potential, kinetic, chemical, thermal, electrical, nuclear, and motion. Potential energy is stored energy due to position or composition, like energy stored in compressed springs or chemical bonds. Kinetic energy is energy in motion, like radiant, thermal, or electrical energy. Energy can be converted from one form to another, though conversions reduce overall efficiency. High-grade energy like electricity is concentrated and can do large amounts of work, while low-grade heat disperses and does less concentrated work. Electrical energy can be direct current, alternating current, measured in volts and amps, and involves concepts like resistance, power, and power factor relating to efficiency.
This document provides an introduction to electricity and electrical systems. It describes the basics of electricity, including electric charge, conductivity, electric potential, electric fields, static electricity, current, potential difference, resistance, and electric circuits. It then discusses different power generation systems, including public utilities, plant generation systems, stand-by generators, emergency power sources, and cogeneration systems. The goal is to help operators better understand the characteristics of electricity and components of electric circuits to feel more comfortable working with electrical equipment.
POWER SYSTEM INTRODUCTION priyank pulkit rads praveerPRIYANK JAIN
The document provides an overview of the electricity sector in India. It discusses how electricity has become essential to modern life and the Indian economy. It then summarizes the history and development of the electricity sector in India, including key milestones like the 1991 reforms that opened the sector to private investment and the 2003 Electricity Act. The document also provides explanations of basic electricity concepts like voltage, current, power, frequency, as well as different components of the power system like generation, transmission, distribution and utilization.
The document discusses various topics related to energy and physics, including different forms of energy, energy transfer and conservation, energy resources, and generating electricity. It provides examples of energy efficiency calculations and discusses advantages and disadvantages of different energy sources. Key terms like kinetic energy, heat, electricity, and renewable vs non-renewable resources are explained.
This document discusses electricity generation and distribution systems. It begins by explaining how electricity is generated through various energy sources like coal, natural gas, and renewable sources that spin turbines connected to generators. It then describes how electricity is transmitted at high voltages for long distances and distributed at lower voltages for local use through step-up and step-down transformers. Finally, it provides an overview of the electrical supply system process from generation to transmission to distribution.
Electricity is a natural phenomenon that occurs throughout nature and takes many different forms. It can be produced from primary energy sources like coal, natural gas, nuclear energy, solar energy, and wind energy. Electricity is then converted into an energy carrier that can power homes and electronic devices through transmission lines and power grids. It involves the flow of electric charge through conductors like copper wires.
This document discusses thermodynamics and various forms of energy. It covers:
1) The first and second laws of thermodynamics - the first law concerns conservation of total energy in a closed system, while the second law concerns the direction of energy flow from hot to cold and limits conversion efficiency to less than 100%.
2) Common forms of energy - including mechanical, electrical, chemical, nuclear, and hydro energy. Electrical energy is widely used due to its versatility.
3) Energy resources - which are classified as primary sources available in nature, intermediate forms after processing primary sources, and secondary usable forms. Efforts seek to develop energy chains with few conversion steps and high efficiency.
Various sources are used to provide electricity to power homes and devices. Hydroelectric power plants use the kinetic energy of falling water to turn turbines which rotate generators, producing electrical current. Other power sources like fossil fuels, nuclear reactions, wind and tides also use generators, converting the energy of motion into electrical energy. Generators have electromagnets surrounded by coils of wire, and their rotation produces the flow of electrons that becomes electricity. Electricity travels through power lines to homes where it powers various appliances and devices. The amount of electrical energy used can be calculated using the power rating and running time of devices.
Energy can exist in many forms including thermal, light, electrical, sound, kinetic, chemical, nuclear, and potential energy. Energy is conserved and can change form but cannot be created or destroyed. Devices transfer energy from one form to another, with some energy being useful output and some lost as wasted heat. Efficiency measures the proportion of useful versus total input energy. Sankey diagrams illustrate energy transfers and efficiency using the width of arrows.
The document discusses photocells and how they work to convert sunlight directly into electrical energy by using silicon crystals. When light energy is absorbed by the silicon, electrons are knocked loose, creating an electric current. The power output increases with greater surface area or light intensity. Photocells have advantages like being renewable and producing no pollution or needing fuel, but cannot generate power at night or in bad weather. Solar panels and passive solar heating are also discussed as methods of collecting solar energy and converting it to heat.
This document provides an overview of basic electricity concepts including:
1) The different states of matter and sources of electricity such as photoelectricity, thermoelectricity, and piezoelectricity. Batteries and generators are mentioned as examples.
2) Key electrical concepts such as voltage, current, power, and resistance are discussed.
3) Electrical circuits are defined as closed loops that allow electricity to flow. Circuit diagrams use symbols to represent components and how they are connected.
4) Common circuit types and components such as resistors and generators are also introduced. Examples of calculating voltage, resistance and power in circuits are provided.
This document provides an overview of electrical generators and related concepts. It begins with the four laws of electromagnetism and then covers topics like electrical machines, energy conversion, hydropower generators, electrical laws and principles, generator construction, and AC vs DC systems. Diagrams are included to illustrate hydroelectric power generation systems, turbine types, generator components, and electrical waveforms. Key terms are defined throughout relating to electromagnetism, energy sources, electrical machines, and generator operation.
WHY ELECRICITY IS IMPORTANT ?
Electricity is an essential part of modern life. People use electricity for lighting, heating, cooling, and refrigeration and for operating appliances, computers, electronics, machinery, and public transportation systems.
Electrical energy is one of the most commonly used forms of energy in the world. It can be easily converted into any other energy form and can be safely and efficiently transported over long distances. As a result, it is used in our daily lives more than any other energy source.
Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Electric power is usually produced by electric generators, but can also be supplied by sources such as electric batteries. http://bit.ly/2PIOIQM
Hydroelectric Power Generation. Hydroelectric Power Generation. Hydroelectric...Alana Cartwright
This document provides an overview of hydroelectric power generation. It discusses how hydroelectric power works by converting the kinetic energy of moving water into electrical energy. Dams are used to store water which is then released to spin turbines connected to generators. The electricity is stepped up in voltage and transmitted via power lines. Hydroelectric power provides flexibility to meet peak energy demands and can be paired with other renewable sources like wind and solar to increase reliability of supply.
PPE at a gls class lecture presentation .pptxAlAMINaj
The document discusses energy sources and power generation. It describes primary energy sources as those directly extracted from nature, divided into renewable and non-renewable sources. Primary energy is converted into secondary energy sources like electricity and steam. Power generation methods are also outlined, along with power transmission and distribution systems. The document provides an overview of power plant types and Bangladesh's current power sector structure and statistics.
This document discusses electrical energy and its generation. It begins by defining electric current as the movement of electric charge carriers like electrons or ions. It then lists various natural and renewable sources that can be used to generate electrical energy, such as natural gas, coal, nuclear power, hydropower, wind, biomass, and solar. The process of electrical energy generation is then summarized as using these sources to boil water, produce steam, turn turbines, and generate electricity that is increased in voltage via transformers for transmission and distribution. The document also discusses how electricity is distributed at lower voltages for household use and some costs associated with electricity consumption and renewable energy commercialization. It concludes that electricity has become an essential part of modern life and our economy
The document introduces electrical machines and defines them as electromagnetic systems that convert energy from one form to another using electromagnetic induction. Electrical machines include generators, which convert mechanical energy to electricity, and motors, which perform the reverse conversion. Transformers and rotary converters are also considered special types of electrical machines. While electrostatic machines can also convert energy, electromagnetic machines are more commonly used due to superior size, weight and cost advantages.
Electricity is the flow of electric charge. It is created by an imbalance of electric charges between objects. There are three main properties of electricity: current, which is the flow of electrons; voltage, which is the difference in electric potential; and resistance, which prevents the flow of electrons. Ohm's law states that voltage equals current times resistance. Electricity is generated by moving a coil of wire through a magnetic field or vice versa, inducing a current. It is transmitted at high voltages to reduce energy loss, then transformed to lower voltages for consumer use.
Reverse osmosis Process with Modified V-SEP technologySagar Joshi
DESIGN & ANALYSIS OF INDUSTRIAL
REVERSE OSMOSIS (RO) PLANT”.
Membrane
Pressure vessel
RO uses a high-pressure which is larger than osmosis pressure on the high
concentration side. So, the carrier is preferentially permeated, while the retentate contains
the rejected solute (contaminant). Thus, the membrane divides the water from the
contaminants. The main aim is to purify water and not dilute the contaminants.‖
Classification, Advantages and applications, Commercially viable
waste heat recovery devices, Saving potential.
Waste heat is heat, which is generated in a process by way of fuel combustion or chemical
reaction, and then “dumped” into the environment even though it could still be reused for some
useful and economic purpose. The essential quality of heat is not the amount but rather its
“value”. The strategy of how to recover this heat depends in part on the temperature of the waste
heat gases and the economics involved.
Vapor compression refrigeration cycle, Refrigerants,
Coefficient of performance, Capacity, Factors affecting Refrigeration and Air conditioning
system performance and savings opportunities.
Vapor absorption refrigeration system: Working principle, Types and comparison with
vapor compression system, Saving potential
Pumps come in a variety of sizes for a wide range of applications. They can be classified
according to their basic operating principle as dynamic or displacement pumps. Dynamic
pumps can be sub-classified as centrifugal and special effect pumps. Displacement pumps can
be sub-classified as rotary or reciprocating pumps.
Light source, Choice of lighting, Luminance requirements, and Energy
conservation avenues
Lighting is an essential service in all the industries. The power consumption by the industrial
lighting varies between 2 to 10% of the total power depending on the type of industry.
Innovation and continuous improvement in the field of lighting, has given rise to tremendous
energy saving opportunities in this area.
Lighting is an area, which provides a major
Types of air compressors, Compressor efficiency, Efficient compressor
operation, Compressed air system components, Capacity assessment, Leakage test,
Factors affecting the performance and efficiency
Types, Combustion in boilers, Performances evaluation, Analysis of losses, Feed
water treatment, Blow down, Energy conservation opportunities.
Types, Combustion in boilers, Performances evaluation, Analysis of losses, Feed
water treatment, Blow down, Energy conservation opportunities.
Defining monitoring & targeting, Elements of monitoring & targeting, Data and information-analysis, Techniques -energy consumption,Production, Cumulative sum of differences (CUSUM).
Investment-need, Appraisal and criteria, Financial analysis techniques-Simple pay back period, Return on investment, Net present value, Internal rate of return, Cash flows, Risk and sensitivity analysis; Financing options, Energy performance contracts and role of ESCOs.
The judicious and effective use of energy to maximize profits (minimize
costs) and enhance competitive positions”
The strategy of adjusting and optimizing energy, using systems and procedures so as to reduce energy requirements per unit of output while holding constant or reducing total costs of producing the output from these systems”
The frame is an integral structural part of an automobile.
It supports power plant , transmission system, wheels and tyres etc.
The body is also fitted on it.
Attachment of all these parts and systems may be rigid or flexible.
The front and rear wheels are connected with the frame by means of spring shackles.
Frames are supported by a suspension system which is attached to the wheels.
This is done for comfortable driving.
Clutch is a mechanism which enables the rotary motion of one shaft to be transmitted, when desired, to a second shaft the axis of which is coincident with that of first.
Clutch is used to engage or disengage the engine to the transmission or gear box.
Lathe is one of the most important machine tools in the metal working industry. A lathe operates on the principle of a rotating work-piece and a fixed cutting tool.
Lathe machine also called “Engine Lathe” because the first type of lathe was driven by a steam engine
Plasma-arc machining (PAM) employs a high-velocity jet of high-temperature gas to melt and displace material in its path. Called PAM, this is a method of cutting metal with a plasma-arc, or tungsten inert-gas-arc, torch.
Plasma-arc machining (PAM) employs a high-velocity jet of high-temperature gas to melt and displace material in its path. Called PAM, this is a method of cutting metal with a plasma-arc, or tungsten inert-gas-arc, torch.
In this process gases are heated and charged to plasma state.
Plasma state is the super heated and electrically ionized gases at approximately
5000° C.
IDP AND UDP PROJECT OF GTU . DETAIL INFORMATIONSagar Joshi
I.D.P. Orientation Program by G.T.U.
Udisha Club
Structure of GTU Innovation Council
IDP/UDP
Review of Techniques & Skill Needed
As it say user defined projects are those projects which are selected by students or are given by faculty but which has a close social resemblances; the work is to be carried out the same way of I.D.P.
Remote Sensing (Look-Look, No Touch) is a much wider field than we will discuss in this lecture series. We will concentrate on that part of RS dealing with
EARTH LAND RESOURCES
REMOTE SENSING includes all methods and techniques used to gain qualitative and quantitative information about distant objects without coming into direct contact with these objects.
Remote Sensing (Look-Look, No Touch) is a much wider field than we will discuss in this lecture series. We will concentrate on that part of RS dealing with
EARTH LAND RESOURCES
INDIAN SPACE RESEARCH ORGANIZATION INSAT FAMILY ,
Asteroid / Comet flyby mission: Possible time frame- 2015
Mission to Mars :Timeframe- 2019
Human Mission : Timeframe 2020
Missions to other planets (Venus, Mercury…Vision beyond 2020)
Asteroid / Comet flyby mission: Possible time frame- 2015
Mission to Mars :Timeframe- 2019
Human Mission : Timeframe 2020
Missions to other planets (Venus, Mercury…Vision beyond 2020)
Asteroid / Comet flyby mission: Possible time frame- 2015
Mission to Mars :Timeframe- 2019
Human Mission : Timeframe 2020
Missions to other planets (Venus, Mercury…Vision beyond 2020)
Television Broadcasting
Direct To Home (DTH)
TV & Radio Networking
This document provides an overview of data acquisition concepts including transducers, signals, signal conditioning, and DAQ hardware. It discusses how transducers convert physical phenomena into measurable signals, the differences between analog and digital signals, and common signal conditioning techniques like amplification. It also describes common components of DAQ devices, and considerations for configuring devices like resolution, range, gain, and code width to optimize measurement precision.
Software Engineering and Project Management - Introduction, Modeling Concepts...Prakhyath Rai
Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
as Design technique: Modeling, abstraction, The Three models. Class Modeling: Object and Class Concept, Link and associations concepts, Generalization and Inheritance, A sample class model, Navigation of class models, and UML diagrams
Building the Analysis Models: Requirement Analysis, Analysis Model Approaches, Data modeling Concepts, Object Oriented Analysis, Scenario-Based Modeling, Flow-Oriented Modeling, class Based Modeling, Creating a Behavioral Model.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
1. 36Bureau of Energy Efficiency
2. BASICS OF ENERGY AND ITS VARIOUS FORMS
Syllabus
Basics of Energy and its various forms: Electricity basics - DC & AC currents,
Electricity tariff, Load management and Maximum demand control, Power factor.
Thermal basics -Fuels, Thermal energy contents of fuel, Temperature & Pressure, Heat
capacity, Sensible and Latent heat, Evaporation, Condensation, Steam, Moist air and
Humidity & Heat transfer, Units and conversion.
2.1 Definition
Energy is the ability to do work and work is the transfer of energy from one form to another. In
practical terms, energy is what we use to manipulate the world around us, whether by exciting
our muscles, by using electricity, or by using mechanical devices such as automobiles. Energy
comes in different forms - heat (thermal), light (radiant), mechanical, electrical, chemical, and
nuclear energy.
2.2 Various Forms of Energy
There are two types of energy - stored (potential) energy and working (kinetic) energy. For
example, the food we eat contains chemical energy, and our body stores this energy until we
release it when we work or play.
2.2.1 Potential Energy
Potential energy is stored energy and the energy of position (gravitational). It exists in various
forms.
Chemical Energy
Chemical energy is the energy stored in the bonds of atoms and molecules. Biomass, petrole-
um, natural gas, propane and coal are examples of stored chemical energy.
Nuclear Energy
Nuclear energy is the energy stored in the nucleus of an atom - the energy that holds the nucle-
us together. The nucleus of a uranium atom is an example of nuclear energy.
Stored Mechanical Energy
Stored mechanical energy is energy stored in objects by the application of a force. Compressed
springs and stretched rubber bands are examples of stored mechanical energy.
2. 2. Basics of Energy and its Various Forms
37Bureau of Energy Efficiency
Gravitational Energy
Gravitational energy is the energy of place or position. Water in a reservoir behind a hydropow-
er dam is an example of gravitational energy. When the water is released to spin the turbines, it
becomes motion energy.
2.2.2 Kinetic Energy
Kinetic energy is energy in motion- the motion of waves, electrons, atoms, molecules and sub-
stances. It exists in various forms.
Radiant Energy
Radiant energy is electromagnetic energy that travels in transverse waves. Radiant energy
includes visible light, x-rays, gamma rays and radio waves. Solar energy is an example of radi-
ant energy.
Thermal Energy
Thermal energy (or heat) is the internal energy in substances- the vibration and movement of
atoms and molecules within substances. Geothermal energy is an example of thermal energy.
Motion
The movement of objects or substances from one place to another is motion. Wind and
hydropower are examples of motion.
Sound
Sound is the movement of energy through substances in longitudinal (compression/rarefaction)
waves.
Electrical Energy
Electrical energy is the movement of electrons. Lightning and electricity are examples of elec-
trical energy.
2.2.3 Energy Conversion
Energy is defined as "the ability to do work." In this sense, examples of work include moving
something, lifting something, warming something, or lighting something. The following is an
example of the transformation of different types of energy into heat and power.
It is difficult to imagine spending an entire day without using energy. We use energy to light our
cities and homes, to power machinery in factories, cook our food, play music, and operate our
TV.
More the number of
conversion stages, lesser
the overall energy
efficiency
Oil burns to generate heat -->
Heat boils water -->
Water turns to steam -->
Steam pressure turns a turbine -->
Turbine turns an electric generator -->
Generator produces electricity -->
Electricity powers light bulbs -->
Light bulbs give off light and heat
3. 2. Basics of Energy and its Various Forms
38Bureau of Energy Efficiency
2.2.4 Grades of Energy
High-Grade Energy
Electrical and chemical energy are high-grade energy, because the energy is concentrated in a
small space. Even a small amount of electrical and chemical energy can do a great amount of
work. The molecules or particles that store these forms of energy are highly ordered and com-
pact and thus considered as high grade energy. High-grade energy like electricity is better used
for high grade applications like melting of metals rather than simply heating of water.
Low-Grade Energy
Heat is low-grade energy. Heat can still be used to do work (example of a heater boiling water),
but it rapidly dissipates. The molecules, in which this kind of energy is stored (air and water
molecules), are more randomly distributed than the molecules of carbon in a coal. This disor-
dered state of the molecules and the dissipated energy are classified as low-grade energy.
2.3 Electrical Energy Basics
Electric current is divided into two types: Directional Current (DC) and Alternating Current
(AC).
Directional (Direct) Current
A non-varying, unidirectional electric current (Example: Current produced by batteries)
Characteristics:
• Direction of the flow of positive and negative charges does not change with time
• Direction of current (direction of flow for positive charges) is constant with time
• Potential difference (voltage) between two points of the circuit does not change polarity
with time
Alternating Current
A current which reverses in regularly recurring intervals of time and which has alternately pos-
itive and negative values, and occurring a specified number of times per second. (Example:
Household electricity produced by generators, Electricity supplied by utilities.)
Characteristics:
· Direction of the current reverses periodically with time
· Voltage (tension) between two points of the circuit changes polarity with time.
· In 50 cycle AC, current reverses direction 100 times a second (two times during onecycle)
Ampere (A)
Current is the rate of flow of charge. The ampere is the basic unit of electric current. It is that
current which produces a specified force between two parallel wires, which are 1 metre apart
in a vacuum.
Voltage (V)
The volt is the International System of Units (SI) measure of electric potential or electromo-
4. 2. Basics of Energy and its Various Forms
39Bureau of Energy Efficiency
kVAr (Reactive Power)
kVAr is the reactive power. Reactive power is the portion of apparent power that does no work.
This type of power must be supplied to all types of magnetic equipment, such as motors, trans-
formers etc. Larger the magnetizing requirement, larger the kVAr.
Kilowatt (kW) (Active Power)
kW is the active power or the work-producing part of apparent power.
tive force. A potential of one volt appears across a resistance of one ohm when a current of one
ampere flows through that resistance.
1000 V = 1 kiloVolts (kV)
Resistance
Voltage
Resistance =
_______
Current
The unit of resistance is ohm (Ω)
Ohm' Law
Ohm's law states that the current through a conductor is directly proportional to the potential
difference across it, provided the temperature and other external conditions remain constant.
Frequency
The supply frequency tells us the cycles at which alternating current changes. The unit of fre-
quency is hertz (Hz :cycles per second).
Kilovolt Ampere (kVA)
It is the product of kilovolts and amperes. This measures the electrical load on a circuit or sys-
tem. It is also called the apparent power.
1000
AmperesxVoltage
(kVA)powerApparent,circuitelectricalphasesingleaFor =
1000
)(,sin
factorPowerxAmperesxVoltage
kWPowerphasegleFor =
1000
732.1
)(,
factorPowerxAmperesxVoltagex
kWPowerphaseThreeFor =
1000
AmperesxVoltagex3
(kVA)powerApparent,circuitelectricalphasethreeaFor =
5. 2. Basics of Energy and its Various Forms
40Bureau of Energy Efficiency
Power Factor
Power Factor (PF) is the ratio between the active power (kW) and apparent power (kVA).
When current lags the voltage like in inductive loads, it is called lagging power factor and when
current leads the voltage like in capacitive loads, it is called leading power factor.
Inductive loads such as induction motors, transformers, discharge lamp, etc. absorb com-
paratively more lagging reactive power (kVAr) and hence, their power factor is poor. Lower the
power factor; electrical network is loaded with more current. It would be advisable to have
highest power factor (close to 1) so that network carries only active power which does real
work. PF improvement is done by installing capacitors near the load centers, which improve
power factor from the point of installation back to the generating station.
Kilowatt-hour (kWh)
Kilowatt-hour is the energy consumed by 1000 Watts in one hour. If 1kW (1000 watts) of a elec-
trical equipment is operated for 1 hour, it would consume 1 kWh of energy (1 unit of electrici-
ty).
For a company, it is the amount of electrical units in kWh recorded in the plant over a month
for billing purpose. The company is charged / billed based on kWh consumption.
Electricity Tariff
Calculation of electric bill for a company
Electrical utility or power supplying companies charge industrial customers not only based on
the amount of energy used (kWh) but also on the peak demand (kVA) for each month.
Contract Demand
Contract demand is the amount of electric power that a customer demands from utility in a spec-
ified interval. Unit used is kVA or kW. It is the amount of electric power that the consumer
agreed upon with the utility. This would mean that utility has to plan for the specified capacity.
Maximum demand
Maximum demand is the highest average kVA recorded during any one-demand interval with-
in the month. The demand interval is normally 30 minutes, but may vary from utility to utility
from 15 minutes to 60 minutes. The demand is measured using a tri-vector meter / digital ener-
gy meter.
6. 2. Basics of Energy and its Various Forms
41Bureau of Energy Efficiency
Prediction of Load
While considering the methods of load prediction, some of the terms used in connection with
power supply must be appreciated.
Connected Load - is the nameplate rating (in kW or kVA) of the apparatus installed on a con-
sumer's premises.
Demand Factor - is the ratio of maximum demand to the connected load.
Load Factor - The ratio of average load to maximum load.
The load factor can also be defined as the ratio of the energy consumed during a given period
to the energy, which would have been used if the maximum load had been maintained through-
out that period. For example, load factor for a day (24 hours) will be given by:
PF Measurement
A power analyzer can measure PF directly, or alternately kWh, kVAh or kVArh readings are
recorded from the billing meter installed at the incoming point of supply. The relation kWh /
kVAh gives the power factor.
Time of Day (TOD) Tariff
Many electrical utilities
like to have flat
demand curve to
achieve high plant effi-
ciency. They encourage
user to draw more
power during off-peak
hours (say during night
time) and less power
during peak hours. As
per their plan, they
offer TOD Tariff,
which may be incen-
tives or disincentives.
Energy meter will
record peak and non-
peak consumption sep-
arately by timer con-
trol. TOD tariff gives
opportunity for the user to reduce their billing, as off peak hour tariff charged are quite low in
comparison to peak hour tariff.
LoadMaximum
LoadAverage
FactorLoad =
HoursxrecordedloadMaximum
hoursduringconsumedEnergy
FactorLoad
24
24
=
7. 2. Basics of Energy and its Various Forms
42Bureau of Energy Efficiency
Three phase AC power measurement
Most of the motive drives such as pumps, compressors, machines etc. operate with 3 phase AC
Induction motor. Power consumption can be determined by using the relation.
Power = √3 x V x I x CosΦ
Portable power analysers /instruments are available for measuring all electrical parameters.
Example:
A 3-phase AC induction motor (20 kW capacity) is used for pumping operation. Electrical
parameter such as current, volt and power factor were measured with power analyzer. Find
energy consumption of motor in one hour? (line volts. = 440 V, line current = 25 amps and PF
= 0.90).
Energy consumption = √ 3 x 0.440 (kV) x 25(A) x 0.90(PF) x 1(hour) = 17.15 kWh
Motor loading calculation
The nameplate details of motor, kW or HP indicate the output parameters of the motor at full
load. The voltage, amps and PF refer to the rated input parameters at full load.
Example:
A three phase,10 kW motor has the name plate details as 415 V, 18.2 amps and 0.9 PF. Actual
input measurement shows 415 V, 12 amps and 0.7 PF which was measured with power analyz-
er during motor running.
Rated output at full load = 10 kW
Rated input at full load = 1.732 x 0.415 x 18.2 x 0.9 = 11.8 kW
The rated efficiency of motor at full load = (10 x 100) / 11.8 = 85%
Measured (Actual) input power = 1.732x 0.415 x 12x 0.7 = 6.0 kW
Which applications use single-phase power in an industry?
Single-phase power is mostly used for lighting, fractional HP motors and electric heater appli-
cations.
Example :
A 400 Watt mercury vapor lamp was switched on for 10 hours per day. The supply volt is 230
V. Find the power consumption per day? (Volt = 230 V, Current = 2 amps, PF = 0.8)
Electricity consumption (kWh) = V x I x Cos x No of Hours
= 0.230 x 2 x 0.8 x 10 = 3.7 kWh or Units
%2.51100
8.11
0.6
100% === xx
kWRated
kWMeasured
loadingMotor
8. Example :
An electric heater of 230 V, 5 kW rating is used for hot water generation in an industry. Find
electricity consumption per hour (a) at the rated voltage (b) at 200 V
(a) Electricity consumption (kWh) at rated voltage = 5 kW x 1 hour = 5 kWh.
(b) Electricity consumption at 200 V (kWh) = (200 / 230)2
x 5 kW x 1 hour = 3.78 kWh.
2.4 Thermal Energy Basics
Temperature and Pressure
Temperature and pressure are measures of the physical state of a substance. They are closely
related to the energy contained in the substance. As a result, measurements of temperature and
pressure provide a means of determining energy content.
Temperature
It is the degree of hotness or coldness measured on a definite scale. Heat is a form of energy;
temperature is a measure of its thermal effects. In other words, temperature is a means of deter-
mining sensible heat content of the substance
In the Celsius scale the freezing point of water is 0°C and the boiling point of water is 100°C
at atmospheric pressure.
To change temperature given in Fahrenheit (°F) to Celsius (°C)
Start with (°F); subtract 32; multiply by 5; divide by 9; the answer is (°C)
To change temperature given in Celsius (°C) to Fahrenheit (°F)
Start with (°C); multiply by 9; divide by 5; add on 32; the answer is (°F)
Pressure
It is the force per unit area applied to outside of a body. When we heat a gas in a confined space,
we create more force; a pressure increase. For example, heating the air inside a balloon will
cause the balloon to stretch as the pressure increases.
Pressure, therefore, is also indicative of stored energy. Steam at high pressures contains
much more energy than at low pressures.
Heat
Heat is a form of energy, a distinct and measurable property of all matter. The quantity of heat
depends on the quantity and type of substance involved.
Unit of Heat
Calorie is the unit for measuring the quantity of heat. It is the quantity of heat, which can raise
the temperature of 1 g of water by 1°C.
Calorie is too small a unit for many purposes. Therefore, a bigger unit Kilocalorie (1 Kilocalorie
2. Basics of Energy and its Various Forms
43Bureau of Energy Efficiency
°C = (°F - 32) x 5/9
9. 2. Basics of Energy and its Various Forms
44Bureau of Energy Efficiency
= 1000 calories) is used to measure heat. 1 kilocalorie can raise the temperature of 1000g (i.e.
1kg) of water by 1°C.
However, nowadays generally joule as the unit of heat energy is used. It is the internation-
ally accepted unit. Its relationship with calorie is as follows:
1 Calorie = 4.187 J
Specific Heat
If the same amount of heat energy is supplied to equal quantities of water and milk, their tem-
perature goes up by different amounts. This property is called the specific heat of a substance
and is defined as the quantity of heat required to raise the temperature of 1kg of a substance
through 1°C.
The specific heat of water is very high as compared to other common substances; it takes a
lot of heat to raise the temperature of water. Also, when water is cooled, it gives out a large
quantity of heat.
Sensible heat
It is that heat which when added or subtracted results in a change of temperature.
Quantity of Heat
The quantity of heat, Q, supplied to a substance to increase its temperature by t°C depends on
– mass of the substance (m)
– increase in temperature (∆t)
– specific heat of the substance (Cp)
TABLE 2.1 SPECIFIC HEAT OF SOME COMMON
SUBSTANCES
Substance Specific Heat (Joules / kg °
C)
Lead 130
Mercury 140
Brass 380
Copper 390
Iron 470
Glass 670
Aluminium 910
Rubber 1890
Ice 2100
Alcohol 2400
Water 4200
10. The quantity of heat is given by:
Q = mass x specific heat x increase in temperature
Q = m x Cp x ∆t
Phase Change
The change of state from the solid state to a liquid state is called fusion. The fixed temperature
at which a solid changes into a liquid is called its melting point.
The change of a state from a liquid state to a gas is called vaporization.
Latent heat of fusion
The latent heat of fusion of a substance is the quantity of heat required to convert 1kg solid to
liquid state without change of temperature. It is represented by the symbol L. Its unit is Joule
per kilogram (J/Kg)
Thus, L (ice) = 336000 J/kg,
Latent Heat of Vaporization
The latent heat of vaporization of a substance is the quantity of heat required to change 1kg of
the substance from liquid to vapour state without change of temperature. It is also denoted by
the symbol L and its unit is also J/kg. The latent heat of vaporization of water is 22,60,000 J/kg.
When 1 kg of steam at 100°C condenses to form water at 100°C, it gives out 2260 kJ (540
kCals) of heat. Steam gives out more heat than an equal amount of boiling water because of its
latent heat.
Latent heat
It is the change in heat content of a substance, when its physical state is changed without a
change in temperature.
Super Heat
The heating of vapour, particularly saturated steam to a temperature much higher than the boil-
ing point at the existing pressure. This is done in power plants to improve efficiency and to
avoid condensation in the turbine.
Humidity
The moisture content of air is referred to as humidity and may be expressed in two ways: spe-
cific humidity and relative humidity.
Specific Humidity
It is the actual weight of water vapour mixed in a kg of dry air.
Humidity Factor
Humidity factor = kg of water per kg of dry air (kg/kg).
2. Basics of Energy and its Various Forms
45Bureau of Energy Efficiency
11. Relative Humidity (RH)
It is the measure of degree of saturation of the air at any dry-bulb (DB) temperature. Relative
humidity given as a percentage is the actual water content of the air divided by the moisture
content of fully saturated air at the existing temperature.
Dew Point
It is the temperature at which condensation of water vapour from the air begins as the temper-
ature of the air-water vapour mixture falls.
Dry bulb Temperature
It is an indication of the sensible heat content of air-water vapour mixtures.
Wet bulb Temperature
It is a measure of total heat content or enthalpy. It is the temperature approached by the dry bulb
and the dew point as saturation occurs.
Dew Point Temperature
It is a measure of the latent heat content of air-water vapour mixtures and since latent heat is a
function of moisture content, the dew point temperature is determined by the moisture content.
Fuel Density
Density is the ratio of the mass of the fuel to the volume of the fuel at a stated temperature.
Specific gravity of fuel
The density of fuel, relative to water, is called specific gravity. The specific gravity of water is
defined as 1. As it is a ratio there are no units. Higher the specific gravity, higher will be the
heating values.
Viscosity
The viscosity of a fluid is a measure of its internal resistance to flow. All liquid fuels decrease
in viscosity with increasing temperature
Calorific Value
Energy content in an organic matter (Calorific Value) can be measured by burning it and mea-
suring the heat released. This is done by placing a sample of known mass in a bomb calorime-
ter, a device that is completely sealed and insulated to prevent heat loss. A thermometer is
placed inside (but it can be read from the outside) and the increase in temperature after the sam-
ple is burnt completely is measured. From this data, energy content in the organic matter can be
found out.
The heating value of fuel is the measure of the heat released during the complete combus-
tion of unit weight of fuel. It is expressed as Gross Calorific Value (GCV) or Net Calorific Value
(NCV). The difference between GCV and NCV is the heat of vaporization of the moisture and
atomic hydrogen (conversion to water vapour) in the fuel. Typical GCV and NCV for heavy fuel
oil are 10,500 kcal/kg and 9,800 kcal/kg.
2. Basics of Energy and its Various Forms
46Bureau of Energy Efficiency
12. Heat Transfer
Heat will always be transferred from higher temperature to lower temperature independent of
the mode. The energy transferred is measured in Joules (kcal or Btu). The rate of energy trans-
fer, more commonly called heat transfer, is measured in Joules/second (kcal/hr or Btu/hr).
Heat is transferred by three primary modes:
o Conduction (Energy transfer in a solid)
o Convection (Energy transfer in a fluid)
o Radiation (Does not need a material to travel through)
Conduction
The conduction of heat takes place, when two bodies are in contact with one another. If one
body is at a higher temperature than the other, the motion of the molecules in the hotter body
will vibrate the molecules at the point of contact in the cooler body and consequently result in
increase in temperature.
The amount of heat transferred by conduction depends upon the temperature difference, the
properties of the material involved, the thickness of the material, the surface contact area, and
the duration of the transfer.
Good conductors of heat are typically substances that are dense as they have molecules
close together. This allows the molecular agitation process to permeate the substance easily. So,
metals are good conductors of heat, while gaseous substance, having low densities or widely
spaced molecules, are poor conductors of heat. Poor conductors of heat are usually called insu-
lators.
The measure of the ability of a substance to insulate is its thermal resistance. This is com-
monly referred to as the R-value (RSI in metric). The R-value is generally the inverse of the
thermal conductivity, the ability to conduct heat.
Typical units of measure for conductive heat transfer are:
Per unit area (for a given thickness)
Metric (SI) : Watt per square meter (W/m2
)
Overall
Metric (SI) : Watt (W) or kilowatts (kW)
Convection
The transfer of heat by convection involves the movement of a fluid such as a gas or liquid from
the hot to the cold portion. There are two types of convection: natural and forced.
In case of natural convection, the fluid in contact with or adjacent to a high temperature
body is heated by conduction. As it is heated, it expands, becomes less dense and consequent-
ly rises. This begins a fluid motion process in which a circulating current of fluid moves past
the heated body, continuously transferring heat away from it.
In the case of forced convection, the movement of the fluid is forced by a fan, pump or other
external means. A centralized hot air heating system is a good example of forced convection.
Convection depends on the thermal properties of the fluid as well as surface conditions at
the body and other factors that affect the ability of the fluid to flow. With a low conductivity
fluid such as air, a rough surface can trap air against the surface reducing the conductive heat
2. Basics of Energy and its Various Forms
47Bureau of Energy Efficiency
13. transfer and consequently reducing the convective currents.
Units of measure for rate of convective heat transfer are:
Metric (SI) : Watt (W) or kilowatts (kW)
Thermal Radiation
Thermal radiation is a process in which energy is transferred by electromagnetic waves similar
to light waves. These waves may be both visible (light) and invisible. A very common example
of thermal radiation is a heating element on a heater. When the heater element is first switched
on, the radiation is invisible, but you can feel the warmth it radiates. As the element heats, it
will glow orange and some of the radiation is now visible. The hotter the element, the brighter
it glows and the more radiant energy it emits.
The key processes in the interaction of a substance with thermal radiation are:
Absorption the process by which radiation enters a body and
becomes heat
Transmission the process by which radiation passes through a body
Reflection the process by which radiation is neither absorbed or transmitted
through the body; rather it bounces off
Objects receive thermal radiation when they are struck by electromagnetic waves, thereby
agitating the molecules and atoms. More agitation means more energy and a higher tempera-
ture. Energy is transferred to one body from another without contact or transporting medium
such as air or water. In fact, thermal radiation heat transfer is the only form of heat transfer pos-
sible in a vacuum.
All bodies emit a certain amount of radiation. The amount depends upon the body's tem-
perature and nature of its surface. Some bodies only emit a small amount of radiant energy for
their temperature, commonly called low emissivity materials (abbreviated low-E). Low-E win-
dows are used to control the heat radiation in and out of buildings. Windows can be designed
to reflect, absorb and transmit different parts of the sun's radiant energy.
The condition of a body's surface will determine the amount of thermal radiation that is
absorbed, reflected or re-emitted. Surfaces that are black and rough, such as black iron, will
absorb and re-emit almost all the energy that strikes them. Polished and smooth surfaces will
not absorb, but reflect, a large part of the incoming radiant energy.
Typical units of measure for rate of radiant heat transfer
Metric (SI) Watt per square meter (W/m2
)
Evaporation
The change by which any substance is converted from a liquid state and carried off as vapour.
Example: People are cooled by evaporation of perspiration from the skin and refrigeration is
accomplished by evaporating the liquid refrigerant. Evaporation is a cooling process.
Condensation
The change by which any substance is converted from a gaseous state to liquid state.
2. Basics of Energy and its Various Forms
48Bureau of Energy Efficiency
14. Example: Condensation on the other hand is a heating process. As molecules of vapour con-
dense and become liquid, their latent heat of vapourisation evidences itself again as sensible
heat, indicated by a rise in temperature. This heating effect of condensation is what causes the
considerable rise in atmospheric temperature often noted as fog forms and as rain or snow
begins to fall.
Steam
Steam has been a popular mode of conveying energy, since the industrial revolution. The fol-
lowing characteristics of steam make it so popular and useful to the industry:
• High specific heat and latent heat
• High heat transfer coefficient
• Easy to control and distribute
• Cheap and inert
Steam is used for generating power and also used in process industries, such as, sugar,
paper, fertilizer, refineries, petrochemicals, chemical, food, synthetic fibre and textiles. In the
process industries, the high pressure steam produced in the boiler, is first expanded in a steam
turbine for generating power. The extraction or bleed from the turbine, which are generally at
low pressure, are used for the process. This method of producing power, by using the steam gen-
erated for process in the boiler, is called "Cogeneration."
How to read a Steam Table?
Select the pressure and temperature of the steam at which you want to find the enthalpy. Read
the intersection of pressure and temperature for enthalpy (Heat content in the steam)
First law of Thermodynamics
It states that energy may be converted from one form to another, but it is never lost from the
system.
Second Law of Thermodynamics
• In any conversion of energy from one form to another, some amount of energy will be dis
sipated as heat.
• Thus no energy conversion is 100 % efficient.
• This principle is used in energy equipment efficiency calculations.
Law of Conservation of Matter
• In any physical or chemical change, matter is neither created nor destroyed, but it may be
changed from one form to another.
• For example, if a sample of coal were burnt in an enclosed chamber, carbon in coal would
end up as CO2
in the air inside the chamber; In fact, for every carbon atom there would be
one carbon dioxide molecule in the combustion products (each of which has one carbon
atom). So the carbon atoms would be conserved, and so would every other atom. Thus, no
matter would be lost during this conversion of the coal into heat.
• This principle is used in energy and material balance calculations
2. Basics of Energy and its Various Forms
49Bureau of Energy Efficiency
15. 2. Basics of Energy and its Various Forms
50Bureau of Energy Efficiency
2.5 Units and Conversions
The energy units are wide and varied. The usage of units varies with country, industry sector,
systems such as FPS, CGS, MKS and SI, and also with generations of earlier period using FPS
and recent generations using MKS. Even technology/equipment suppliers adopt units that are
different from the one being used by the user of that technology/equipment. For example some
compressor manufacturers specify output in m3
/min while some specify in cubic feet/minute or
even in litres/second. All this cause confusion and hence the need for this chapter on units and
conversions.
Energy Units
1 barrel of oil = 42 U.S. gallons (gal) = 0.16 cubic meters (m3
)
1 MW 1,000 kW
1 kW 1,000 Watts
1 kWh 3,412 Btu
1 kWh 1.340 Hp hours
1,000 Btu 0.293 kWh
1 Therm 100,000 Btu (British Thermal Units)
1 Million Btu 293.1 Kilowatt hours
100,000 Btu 1 Therm
1 Watt 3.412 Btu per hour
1 Horsepower 746 Watts or 0.746 Kilo Watts
1 Horsepower hr. 2,545 Btu
1 kJ 0.239005 Kilocalories
1 Calorie 4.187 Joules
1 kcal/Kg 1.8 Btu's/lb.
1 Million Btu 252 Mega calories
1 Btu 252 Calories
1 Btu 1,055 Joules
1 Btu/lb. 2.3260 kJ/kg
1 Btu/lb. 0.5559 Kilocalories/kg
Power (Energy Rate) Equivalents
1 kilowatt (kW) 1 kilo joule /second (kJ/s)
1 kilowatt (kW) 3413 BTU/hour (Btu/hr.)
1 horsepower (hp) 746 watts (0.746 kW)
1 Ton of refrigeration 12000 Btu/hr.
Pressure:
Gauge pressure is defined relative to the prevailing atmospheric pressure (101.325 kPa at sea
level), or as absolute pressure:
Absolute Pressure = Gauge Pressure + Prevailing Atmospheric Pressure
16. Units of measure of pressure:
Metric (SI) : kilopascals (kPa)
1 pascal (Pa) = 1 Newton/m2
(N/m2
)
1 physical atmosphere (atm) = 101325 Pa = 760 mm of mercury (mm Hg)
= 14.69 lb-force/in2
(psi)
1 technical atmosphere (ata) = 1 kilogram-force/cm2
(kg/cm2
)= 9.806650 × 104
Pa
Power:
1 W = 1 J/s = 0.9478×10-3
Btu/s = 3.41214 Btu/hr
Fuel to kWh (Approximate conversion)
2. Basics of Energy and its Various Forms
51Bureau of Energy Efficiency
Natural gas M3
x 10.6 kWh
Ft3
x 0.3 kWh
therms x 29.3 kWh
LPG (propane) m3
x 25 kWh
Coal kg x 8.05 kWh
Coke kg x 10.0 kWh
Gas oil litres x 12.5 kWh
Light fuel oil litres x 12.9 kWh
Medium fuel oil litres x 13.1 kWh
Heavy fuel oil litres x 13.3 kWh
Prefixes for units in the International System
Prefix Symbol Power Example USA/Other
exa E 1018
quintillion
peta P 1015
pentagram (Pg) quadrillion/billiard
tera T 1012
terawatt (TW) trillion/billion
giga G 109
gigawatt (GW) billion/milliard
mega M 106
megawatt (MW) million
kilo k 103
kilogram (kg)
hecto h 102
hectoliter (hl)
deka da 101
dekagram (dag)
deci d 10-1
decimeter (dm)
centi c 10-2
centimeter (cm)
milli m 10-3
millimeter (mm)
micro µ 10-6
micrometer (µm)
nano n 10-9
nanosecond (ns)
pico p 10-12
picofarad (pf)
femto f 10-15
femtogram (fg)
atto a 10-18
17. 2. Basics of Energy and its Various Forms
52Bureau of Energy Efficiency
To: TJ Gcal Mtoe MBtu GWh
From: Multiply by:
TJ 1 238.8 2.388 x 10-5
947.8 0.2778
Gcal 4.1868 x 10-3
1 10-7
3.968 1.163 x 10-3
Mtoe 4.1868 x 104
107
1 3.968 x 107
11630
MBtu 1.0551 x 10-3
0.252 2.52 x 10-8
1 2.931 x 10-4
GWh 3.6 860 8.6 x 10-5
3412 1
Energy
To: kg t lt st lb
From: multiply by:
kilogram (kg) 1 0.001 9.84 x 10-4
1.102 x 10-3
2.2046
tonne (t) 1000 1 0.984 1.1023 2204.6
long ton (lt) 1016 1.016 1 1.120 2240.0
short ton (st) 907.2 0.9072 0.893 1 2000.0
pound (lb) 0.454 4.54 x 10-4
4.46 x 10-4
5.0 x 10-4
1
Mass
To: gal U.S. gal U.K. bbl ft3
l m3
From: multiply by:
U.S. gallon (gal) 1 0.8327 0.02381 0.1337 3.785 0.0038
U.K. gallon (gal) 1.201 1 0.02859 0.1605 4.546 0.0045
Barrel (bbl) 42.0 34.97 1 5.615 159.0 0.159
Cubic foot (ft3
) 7.48 6.229 0.1781 1 28.3 0.0283
Litre (l) 0.2642 0.220 0.0063 0.0353 1 0.001
Cubic metre (m3
) 264.2 220.0 6.289 35.3147 1000.0 1
Volume
18. 2. Basics of Energy and its Various Forms
53Bureau of Energy Efficiency
QUESTIONS
1. Discuss one energy conversion activity with various losses occurring stage wise.
2. The reactive power is represented by
(a) kVA (b) kW (c) kVAr (d) PF
3. A fluorescent tube light consumes 40 W for the tube and 10 W for choke. If the
lamp operates for 8 hours a day for 300 days in a year, calculate the total energy cost
per annum if the energy cost is Rs.3/- per kWh
4. Power factor is the ratio of
(a) kW / kVA (b) kVA / kW (c) kVA / kVAr (d) kVAr / kV
5. Define the term load factor.
6. What do you understand by the term calorific value?
7. What are the three modes of heat transfer? Explain with examples?
8. Explain why steam is used commonly in industries?
9. If an electric heater consumes 4 kWh, what will be the equivalent kilocalories?
10. Why a cube of ice at 0o
C is more effective in cooling a drink than the same quantity
of water at 0o
C?
11. 10 kg of steam at 100o
C with latent heat of vapourisation 2260 kJ is cooled to 50o
C.
If the specific heat of water is 4200 J/kgo
C, find the quantity of heat given out.
REFERENCES
1. Energy Dictionary, Van Nostrand Reinhold Company, New York - V Daniel Hunt.
2. Cleaner Production – Energy Efficiency Manual for GERIAP, UNEP, Bangkok prepared
by National Productivity Council
www.eia.doe.gov/kids/btudef.html
www.calculator.org/properties.html
www.katmarsoftware.com