Navin Kohli - Academia.edu (original) (raw)
Papers by Navin Kohli
Substantial scientific evidence indicates that an increase in the global average temperature of m... more Substantial scientific evidence indicates that an increase in the global average temperature of more than 2° C above pre-industrial levels poses severe risks to natural systems & human health. Sustained warming of this magnitude could, for example, result in the extinction of many species & extensive melting of the Greenland and West Antarctic ice sheets causing global sea level to rise between 12 and 40 feet. Australia’s residents have modern and energy reliant lifestyles leading to a very high value of carbon footprint of around 18.4 tonnes of CO 2/ capita/year. Australia is one of the top 20 polluting countries in the world and produces more carbon pollution per person than any other developed country in the world. Australia's emissions are projected to increase by 24 per cent between 2000 and 2020. Recognising the importance of responding to the climate change challenge, countries all over the world are acting to reduce their emissions. Australia needs to reduce its carbon p...
The primary application of wind turbines is to extract energy from the wind. Thus, the aerodynami... more The primary application of wind turbines is to extract energy from the wind. Thus, the aerodynamics is a very important aspect of wind turbines and aerodynamics of one wind turbine to the other can be very different. There performance varies from turbine characteristics. The traditional method of measuring wind turbine performance under laboratory conditions in ideal circumstances always tend to be optimistic & hardly reflect how the turbine actually behaves in actual. Real performance affected by local wind conditions, nearby obstructions, power demand profiles and a range of other factors. The wind turbine characteristics are Rotor diameter, Mean wind speed, Cut in speed, Cut out speed, Turbine efficiency and Weibull shape parameter. There is deterioration in performance with time due to wear and tear. What is important is how the turbine reacts and actually delivers power on site. Without proper data this can be very subjective and a matter of personal opinion. These characterist...
Inventi, 2012
Abstracts: Electricity plays a central role in improving the quality of life in India. Even those... more Abstracts: Electricity plays a central role in improving the quality of life in India. Even those with access to electricity in India do not always have a reliable supply. Currently protecting electricity consumer’s interest is another challenge in India. Good quality electrical service is linked to effective end use. The performance measures of state owned power utilities (SOPUs) are very important aspect of consumer services in distribution reform. This performance benchmarking process can reveal potential areas where a particular power utilities performance is lacking and point to directions for further detailed examination to identify any underlying contributing causes or mitigating factors to the performance gap. Performance evaluation of SOPU is vital quality of electricity service throughout the world. While the forms of performance benchmarking vary in the United States, Europe, Japan, and other developed countries. The standard of performance is the necessary feature for developing country like India. Utilities use quantitative measures to compare operational performance among their distribution units to assure that they provide a uniform quality of service, anticipate problems, guide capital expenditures, and increasingly to monitor their competitiveness towards customer services. Regulators rely on cross-utility studies of service quality and cost of service for a wide variety of functions every time they consider a utility’s application to increase consumer tariffs. The paper endeavored to develop a set of matrices and evaluation methods for measuring performance efficiency of SOPUs with respect to their peer group. Best and efficient SOPUs are counted and helped for further improvement for less efficient SOPUs.
Substantial scientific evidence indicates that an increase in the global average temperature of m... more Substantial scientific evidence indicates that an increase in the global average temperature of more than 2° C above pre-industrial levels poses severe risks to natural systems & human health. Sustained warming of this magnitude could, for example, result in the extinction of many species & extensive melting of the Greenland and West Antarctic ice sheets causing global sea level to rise between 12 and 40 feet. Australia's residents have modern and energy reliant lifestyles leading to a very high value of carbon footprint of around 18.4 tonnes of CO 2 / capita/year. Australia is one of the top 20 polluting countries in the world and produces more carbon pollution per person than any other developed country in the world. Australia's emissions are projected to increase by 24 per cent between 2000 and 2020. Recognising the importance of responding to the climate change challenge, countries all over the world are acting to reduce their emissions. Australia needs to reduce its carbon pollution and its action plan. The paper here discusses ways of emission reductions using application of conservation & energy efficiency strategies in energy inefficient Australians' households. This paper elaborates various reasons why carbon footprints of different households within the country differ. Various technologies and strategies have been proposed to mitigate. A detailed assessment made indicating conservation and energy efficient strategies applied to reduce emissions to subject household. The mitigation strategies present & quantitative measure of their impact defining the factors contributes towards reduction of emissions.
—The primary application of wind turbines is to extract energy from the wind. Thus, the aerodynam... more —The primary application of wind turbines is to extract energy from the wind. Thus, the aerodynamics is a very important aspect of wind turbines and aerodynamics of one wind turbine to the other can be very different. There performance varies from turbine characteristics. The traditional method of measuring wind turbine performance under laboratory conditions in ideal circumstances always tend to be optimistic & hardly reflect how the turbine actually behaves in actual. Real performance affected by local wind conditions, nearby obstructions, power demand profiles and a range of other factors. The wind turbine characteristics are Rotor diameter, Mean wind speed, Cut in speed, Cut out speed, Turbine efficiency and Weibull shape parameter. There is deterioration in performance with time due to wear and tear. What is important is how the turbine reacts and actually delivers power on site. Without proper data this can be very subjective and a matter of personal opinion. These characteristics are discussed in reference to performance of wind turbine in this paper.
In this World, wind energy is renewable resource and free. No matter if excess is used, even thou... more In this World, wind energy is renewable resource and free. No matter if excess is used, even though there shall be supply available in abandoned in future. Wind energy is also a source of clean, non-polluting, electricity. Wind power plants emit no air pollutants or greenhouse gases like other conventional plants do. The power available from wind is become very important now. The only way the power production can be optimized at any specific wind velocity is through maximizing the power coefficient, Cp, of the wind turbine. In this regard, winglets can be used, since these can improve the power production without increasing the projected rotor area. Winglets are wing tip devices commonly used in the aeronautical industry to reduce drag. Few investigations show that winglets can be used in wind turbine blades for maximizing the maximum power produced and accordingly the paper endeavored. The present paper discusses and projected hypothetical work based on earlier study done as it explores the possibility of increasing the efficiency of the large capacity HAWT wind turbine rotor by adding winglets at the tip of the blade. The effects of changing the winglet configuration with the blade on the power performance of large wind turbine based on small rotor models that were studied. The maximum power coefficient with an effective winglet configuration is about 0.50 in place of earlier achievement of 0.52. In the study at present Vestas V80, Vestas V112 and model E126 were studied and improved power performance has been envisaged. The maximum power achieved on theoretical study was from around 3 MW to 9 MW.
It is imperative that wind turbine is a modern concept in our country for using free natural reso... more It is imperative that wind turbine is a modern concept in our country for using free natural resources. Many earlier studies have been conducted on aerodynamic performance and geometric characteristics of large capacity Horizontal Axis Wind Turbine (HAWT) rotors between 3 MW to around 10 MW. The present study have been performed varying the key performance characteristic parameters like rated wind speed, blade tip speed, coefficient of performance, tip speed ratio and using winglet at the tip. The basic objective of the study is efficient performance wind turbine with a highest possible annual usable energy pattern factor and least possible dimension, getting the maximum wind energy (kWh) and producing the maximum power in MW. The impact of these performance parameters on the HAWT rotor geometry has been investigated. The variation patterns of aerodynamic and geometric parameters are obtained, analyzed and discussed. The same then compared with each other and with the existing large capacity HAWT machines of reputed manufacturers. This study analysis and its results can be a basis for evaluating aerodynamic performance of large capacity HAWT wind turbine. The current study provides a detail configuration of wind turbine blade design that indicates dominance of modern HAWT which is for use of horizontal axis rotors.
Substantial scientific evidence indicates that an increase in the global average temperature of m... more Substantial scientific evidence indicates that an increase in the global average temperature of more than 2° C above pre-industrial levels poses severe risks to natural systems & human health. Sustained warming of this magnitude could, for example, result in the extinction of many species & extensive melting of the Greenland and West Antarctic ice sheets causing global sea level to rise between 12 and 40 feet. Australia’s residents have modern and energy reliant lifestyles leading to a very high value of carbon footprint of around 18.4 tonnes of CO 2/ capita/year. Australia is one of the top 20 polluting countries in the world and produces more carbon pollution per person than any other developed country in the world. Australia's emissions are projected to increase by 24 per cent between 2000 and 2020. Recognising the importance of responding to the climate change challenge, countries all over the world are acting to reduce their emissions. Australia needs to reduce its carbon p...
The primary application of wind turbines is to extract energy from the wind. Thus, the aerodynami... more The primary application of wind turbines is to extract energy from the wind. Thus, the aerodynamics is a very important aspect of wind turbines and aerodynamics of one wind turbine to the other can be very different. There performance varies from turbine characteristics. The traditional method of measuring wind turbine performance under laboratory conditions in ideal circumstances always tend to be optimistic & hardly reflect how the turbine actually behaves in actual. Real performance affected by local wind conditions, nearby obstructions, power demand profiles and a range of other factors. The wind turbine characteristics are Rotor diameter, Mean wind speed, Cut in speed, Cut out speed, Turbine efficiency and Weibull shape parameter. There is deterioration in performance with time due to wear and tear. What is important is how the turbine reacts and actually delivers power on site. Without proper data this can be very subjective and a matter of personal opinion. These characterist...
Inventi, 2012
Abstracts: Electricity plays a central role in improving the quality of life in India. Even those... more Abstracts: Electricity plays a central role in improving the quality of life in India. Even those with access to electricity in India do not always have a reliable supply. Currently protecting electricity consumer’s interest is another challenge in India. Good quality electrical service is linked to effective end use. The performance measures of state owned power utilities (SOPUs) are very important aspect of consumer services in distribution reform. This performance benchmarking process can reveal potential areas where a particular power utilities performance is lacking and point to directions for further detailed examination to identify any underlying contributing causes or mitigating factors to the performance gap. Performance evaluation of SOPU is vital quality of electricity service throughout the world. While the forms of performance benchmarking vary in the United States, Europe, Japan, and other developed countries. The standard of performance is the necessary feature for developing country like India. Utilities use quantitative measures to compare operational performance among their distribution units to assure that they provide a uniform quality of service, anticipate problems, guide capital expenditures, and increasingly to monitor their competitiveness towards customer services. Regulators rely on cross-utility studies of service quality and cost of service for a wide variety of functions every time they consider a utility’s application to increase consumer tariffs. The paper endeavored to develop a set of matrices and evaluation methods for measuring performance efficiency of SOPUs with respect to their peer group. Best and efficient SOPUs are counted and helped for further improvement for less efficient SOPUs.
Substantial scientific evidence indicates that an increase in the global average temperature of m... more Substantial scientific evidence indicates that an increase in the global average temperature of more than 2° C above pre-industrial levels poses severe risks to natural systems & human health. Sustained warming of this magnitude could, for example, result in the extinction of many species & extensive melting of the Greenland and West Antarctic ice sheets causing global sea level to rise between 12 and 40 feet. Australia's residents have modern and energy reliant lifestyles leading to a very high value of carbon footprint of around 18.4 tonnes of CO 2 / capita/year. Australia is one of the top 20 polluting countries in the world and produces more carbon pollution per person than any other developed country in the world. Australia's emissions are projected to increase by 24 per cent between 2000 and 2020. Recognising the importance of responding to the climate change challenge, countries all over the world are acting to reduce their emissions. Australia needs to reduce its carbon pollution and its action plan. The paper here discusses ways of emission reductions using application of conservation & energy efficiency strategies in energy inefficient Australians' households. This paper elaborates various reasons why carbon footprints of different households within the country differ. Various technologies and strategies have been proposed to mitigate. A detailed assessment made indicating conservation and energy efficient strategies applied to reduce emissions to subject household. The mitigation strategies present & quantitative measure of their impact defining the factors contributes towards reduction of emissions.
—The primary application of wind turbines is to extract energy from the wind. Thus, the aerodynam... more —The primary application of wind turbines is to extract energy from the wind. Thus, the aerodynamics is a very important aspect of wind turbines and aerodynamics of one wind turbine to the other can be very different. There performance varies from turbine characteristics. The traditional method of measuring wind turbine performance under laboratory conditions in ideal circumstances always tend to be optimistic & hardly reflect how the turbine actually behaves in actual. Real performance affected by local wind conditions, nearby obstructions, power demand profiles and a range of other factors. The wind turbine characteristics are Rotor diameter, Mean wind speed, Cut in speed, Cut out speed, Turbine efficiency and Weibull shape parameter. There is deterioration in performance with time due to wear and tear. What is important is how the turbine reacts and actually delivers power on site. Without proper data this can be very subjective and a matter of personal opinion. These characteristics are discussed in reference to performance of wind turbine in this paper.
In this World, wind energy is renewable resource and free. No matter if excess is used, even thou... more In this World, wind energy is renewable resource and free. No matter if excess is used, even though there shall be supply available in abandoned in future. Wind energy is also a source of clean, non-polluting, electricity. Wind power plants emit no air pollutants or greenhouse gases like other conventional plants do. The power available from wind is become very important now. The only way the power production can be optimized at any specific wind velocity is through maximizing the power coefficient, Cp, of the wind turbine. In this regard, winglets can be used, since these can improve the power production without increasing the projected rotor area. Winglets are wing tip devices commonly used in the aeronautical industry to reduce drag. Few investigations show that winglets can be used in wind turbine blades for maximizing the maximum power produced and accordingly the paper endeavored. The present paper discusses and projected hypothetical work based on earlier study done as it explores the possibility of increasing the efficiency of the large capacity HAWT wind turbine rotor by adding winglets at the tip of the blade. The effects of changing the winglet configuration with the blade on the power performance of large wind turbine based on small rotor models that were studied. The maximum power coefficient with an effective winglet configuration is about 0.50 in place of earlier achievement of 0.52. In the study at present Vestas V80, Vestas V112 and model E126 were studied and improved power performance has been envisaged. The maximum power achieved on theoretical study was from around 3 MW to 9 MW.
It is imperative that wind turbine is a modern concept in our country for using free natural reso... more It is imperative that wind turbine is a modern concept in our country for using free natural resources. Many earlier studies have been conducted on aerodynamic performance and geometric characteristics of large capacity Horizontal Axis Wind Turbine (HAWT) rotors between 3 MW to around 10 MW. The present study have been performed varying the key performance characteristic parameters like rated wind speed, blade tip speed, coefficient of performance, tip speed ratio and using winglet at the tip. The basic objective of the study is efficient performance wind turbine with a highest possible annual usable energy pattern factor and least possible dimension, getting the maximum wind energy (kWh) and producing the maximum power in MW. The impact of these performance parameters on the HAWT rotor geometry has been investigated. The variation patterns of aerodynamic and geometric parameters are obtained, analyzed and discussed. The same then compared with each other and with the existing large capacity HAWT machines of reputed manufacturers. This study analysis and its results can be a basis for evaluating aerodynamic performance of large capacity HAWT wind turbine. The current study provides a detail configuration of wind turbine blade design that indicates dominance of modern HAWT which is for use of horizontal axis rotors.