The document discusses wind energy and wind turbines. It begins by explaining how wind is formed from pressure gradients and the Coriolis effect. It then discusses different types of winds and how wind speed and patterns vary over time. Methods for measuring wind are presented, including wind atlases. The basics of how wind power is captured by wind turbines are covered, including swept area, power output formulas, and optimal turbine spacing in wind farms. Environmental impacts and public acceptance issues are also summarized.
Math cad effective radiation heat transfer coefficient.xmcdJulio Banks
This file demonstrates the use of radiation heat transfer coefficient, the calculation of the heat flux and subsequent heat transfer. The recommendation of estimating the relevance of using radiation heat transfer by comparing the radiation heat transfer coefficient to those of free or forced heat transfer coefficient.
Impact of Electrification on Asset Life Degradation and Mitigation with DERPower System Operation
Distribution networks are currently faced with a plethora of changes in resources, equipment technology, structure, and loading. First, Distributed Energy Resources (DERs) have been increasingly penetrating distribution grids worldwide. DERs have been recognized as a Non-Wires Alternative (NWA) in certain use cases including peak shaving, renewable integration etc). The second imminent change in distribution networks is the electrification of loads, especially in the transportation and space heating sectors, driven at least in part by clean-air and sustainability goals. Electrification is expected to result in higher peak load levels as well as flatter daily and annual load shapes, due to the fact that it is primarily composed of off-peak and by storage-like loads like those of EVs, storage, and electric heating. Their valley-filling behavior results in distribution network apparatus being consistently loaded to high utilization levels.
As a result of these changes in load curve shape, distribution equipment may be subjected to increased operational stress compared to what it endured in the past, even if not loaded to higher net peak loads. For example, in the United States, the majority of distribution substation transformers typically warm up during the morning and afternoon as they approach demand peaks and then cool down afterwards as loading falls. Cumulative loss of life from this repetitive daily cycle is slow, so that expected service life of a typical unit is on the order of fifty years or more, even allowing for periods of intense overload during very rare contingencies. This has been the norm for the US electric utility industry in the last seventy years, but may no longer be the case in environments where electrification is more prevalent.
Math cad effective radiation heat transfer coefficient.xmcdJulio Banks
This file demonstrates the use of radiation heat transfer coefficient, the calculation of the heat flux and subsequent heat transfer. The recommendation of estimating the relevance of using radiation heat transfer by comparing the radiation heat transfer coefficient to those of free or forced heat transfer coefficient.
Impact of Electrification on Asset Life Degradation and Mitigation with DERPower System Operation
Distribution networks are currently faced with a plethora of changes in resources, equipment technology, structure, and loading. First, Distributed Energy Resources (DERs) have been increasingly penetrating distribution grids worldwide. DERs have been recognized as a Non-Wires Alternative (NWA) in certain use cases including peak shaving, renewable integration etc). The second imminent change in distribution networks is the electrification of loads, especially in the transportation and space heating sectors, driven at least in part by clean-air and sustainability goals. Electrification is expected to result in higher peak load levels as well as flatter daily and annual load shapes, due to the fact that it is primarily composed of off-peak and by storage-like loads like those of EVs, storage, and electric heating. Their valley-filling behavior results in distribution network apparatus being consistently loaded to high utilization levels.
As a result of these changes in load curve shape, distribution equipment may be subjected to increased operational stress compared to what it endured in the past, even if not loaded to higher net peak loads. For example, in the United States, the majority of distribution substation transformers typically warm up during the morning and afternoon as they approach demand peaks and then cool down afterwards as loading falls. Cumulative loss of life from this repetitive daily cycle is slow, so that expected service life of a typical unit is on the order of fifty years or more, even allowing for periods of intense overload during very rare contingencies. This has been the norm for the US electric utility industry in the last seventy years, but may no longer be the case in environments where electrification is more prevalent.
Boiling and Condensation heat transfer -- EES Functions and Procedurestmuliya
This file contains notes on Engineering Equation Solver (EES) Functions and Procedures for Boiling and Condensation heat transfer. Some problems are also included.
These notes were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
Contents: Summary of formulas used -
EES Functions/Procedures for boiling: Nucleate boiling heat flux for any geometry - critical heat flux for large horizontal surface, horizontal cylinder and sphere - Film boiling for horizontal cylinder, sphere and horizontal surface – Problems.
EES Functions/Procedures for condensation of: steam on vertical surface – any fluid on a vertical surface – steam on vertical cylinder – any fluid on vertical cylinder – steam on horizontal cylinder – any fluid on horizontal cylinder – steam on a horizontal tube bank – any fluid on horizontal tube bank – any fluid on a sphere – any fluid inside a horizontal cylinder - Problems.
It is hoped that these notes will be useful to teachers, students, researchers and professionals working in this field.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Boiling and Condensation heat transfer -- EES Functions and Procedurestmuliya
This file contains notes on Engineering Equation Solver (EES) Functions and Procedures for Boiling and Condensation heat transfer. Some problems are also included.
These notes were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
Contents: Summary of formulas used -
EES Functions/Procedures for boiling: Nucleate boiling heat flux for any geometry - critical heat flux for large horizontal surface, horizontal cylinder and sphere - Film boiling for horizontal cylinder, sphere and horizontal surface – Problems.
EES Functions/Procedures for condensation of: steam on vertical surface – any fluid on a vertical surface – steam on vertical cylinder – any fluid on vertical cylinder – steam on horizontal cylinder – any fluid on horizontal cylinder – steam on a horizontal tube bank – any fluid on horizontal tube bank – any fluid on a sphere – any fluid inside a horizontal cylinder - Problems.
It is hoped that these notes will be useful to teachers, students, researchers and professionals working in this field.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
In this presentation, we discuss ambitious solutions for fighting climate change and present the first results of the Katabata project. The goal of this project was to install weather stations in very windy parts of Greenland, as a first step to harvest wind energy there.
Download a power point version of this presentation with higher quality images at the following address: https://orbi.uliege.be/handle/2268/251827
In this presentation, we discuss several major engineering projects that should be put in place for fighting climate change at a cheap cost. Among others: a global electrical grid, carbon capture technologies, power-to-gas devices.
Betz's law indicates the maximum power that can be extracted from the wind, independent of the design of a wind turbine in open flow. It was published in 1919, by the German physicist Albert Betz.[1] The law is derived from the principles of conservation of mass and momentum of the air stream flowing through an idealized "actuator disk" that extracts energy from the wind stream. According to Betz's law, no turbine can capture more than 16/27 (59.3%) of the kinetic energy in wind. The factor 16/27 (0.593) is known as Betz's coefficient. Practical utility-scale wind turbines achieve at peak 75% to 80% of the Betz limit.[2][3]
The Betz limit is based on an open disk actuator. If a diffuser is used to collect additional wind flow and direct it through the turbine, more energy can be extracted, but the limit still applies to the cross-section of the entire structure.A wind turbine is a device that converts kinetic energy from the wind into electrical power. The term appears to have migrated from parallel hydroelectric technology (rotary propeller). The technical description for this type of machine is an aerofoil-powered generator.
The result of over a millennium of windmill development and modern engineering, today's wind turbines are manufactured in a wide range of vertical and horizontal axis types. The smallest turbines are used for applications such as battery charging for auxiliary power for boats or caravans or to power traffic warning signs. Slightly larger turbines can be used for making contributions to a domestic power supply while selling unused power back to the utility supplier via the electrical grid. Arrays of large turbines, known as wind farms, are becoming an increasingly important source of renewable energy and are used by many countries as part of a strategy to reduce their reliance on fossil fuels.
Analytic Model of Wind Disturbance Torque on Servo Tracking AntennaIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
The second law of thermodynamics is explored in this lecture. Topics covered include:
Introduction to the second law
Thermal energy reservoirs
Heat engines
Thermal efficiency
The 2nd law: Kelvin-Planck statement
Refrigerators and heat pumps
Coefficient of performance (COP)
The 2nd law: Clasius statement
Perpetual motion machines
Reversible and irreversible processes
Irreversibility's, Internal and externally reversible processes
The Carnot cycle
The reversed Carnot cycle
The Carnot principles
The thermodynamic temperature scale
The Carnot heat engine
The quality of energy
The Carnot refrigerator and heat pump
Mass flow and energy analysis of control systems is the focus of this lecture
Conservation of mass
Mass and volume flow rates
Mass balance for a steady flow process
Mass balance for incompressible flow
Flow work and the energy of a flowing fluid
his lecture examines both work and energy in closed systems and categorises the different types of closed systems that will be encountered.
Moving boundary work
Boundary work for an isothermal process
Boundary work for a constant-pressure process
Boundary work for a polytropic process
Energy balance for closed systems
Energy balance for a constant-pressure expansion or compression process
Specific heats
Constant-pressure specific heat, cp
Constant-volume specific heat, cv
Internal energy, enthalpy and specific heats of ideal gases
Energy balance for a constant-pressure expansion or compression process
Internal energy, enthalpy and specific heats of incompressible substances (Solids and liquids)
Identifying the correct properties of a substance is of vital importance. Many of these properties are distilled from property tables. This lecture addresses how to identify these properties.
Pure substance
Phases of a pure substance
Phase change processes of pure substances
Compressed liquid, Saturated liquid, Saturated vapor, Superheated vapor Saturated temperature and Satuated pressure
Property diagrams for phase change processes
The T-v diagram, The P-v diagram, The P-T diagram, The P-v-T diagram
Property tables
Enthalpy
Saturated liquid, Saturated vapor, Saturated liquid vapor mixture, Superheated vapor, compressed liquid
Reference state and Reference values
The ideal gas equation of state
Is water vapor an ideal gas?
Lecture covering the basic concepts required for the module:
Systems and control volumes
Properties of a system
Density and specific gravity
State and equilibrium
The state postulate
Processes and cycles
The state-flow process
Temperature and the zeroth law of thermodynamics
Temperature scales
Pressure
Variation of pressure with depths
7. Source: Figure 7.5 in The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001
8.
9. Source: Figure 7.6 in The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001
10. Idealized winds generated by pressure Actual wind patterns owing to land mass
gradient and Coriolis Force. distribution..
11. Idealized winds generated by pressure Actual wind patterns owing to land mass
gradient and Coriolis Force. distribution..
Source: Figure 7.8 in The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001
12.
13. Source: Figure 7.9 in The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001
14. Source: Figure 7.9 in The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001
15.
16.
17. Types of Wind
• Geostrophic wind/
Prevailing wind
• Storms
• Local winds/Sea
breezes
• Mountain wind/Valley
wind Sea and Land Breeze
23. Power in the wind
Lesson Number 1. in an Oklahoma Wind Power Tutorial Series
By Tim Hughes, Environmental Verification and Analysis Center, The University of Oklahoma
Calculation of Wind Energy and Power
Calculating the energy (and later power) available in the wind relies on knowledge of basic
geometry and the physics behind kinetic energy. The kinetic energy (KE) of an object (or
collection of objects) with total mass M and velocity V is given by the expression:
KE = ! * M * V2
(1)
1
P = ρ Av 3
Air parcel
Now, for purposes of finding the kinetic energy of
2 moving air molecules (i.e.:wind), let's say one has
a large air parcel with the shape of a huge hockey puck:
ρ = Air density that is, it has the geometry of a collection of air molecules
passing though the plane of a wind turbine's blades (which
A = Swept area of rotor out a cross-sectional area A), with thickness (D)
sweep
passing through the plane over a given time. A Air flow
v = wind speed
The volume (Vol) of this parcel is determined
by the parcel's area multiplied by its thickness:
Therefore, Power availableVol = A * D
is
Proportional to the air density letter 'rho') represent the density
Let ! (the greek
Proportional to the square ofand is expressed as:diameter
the rotor
of the air in this parcel. Note that density is mass
per volume
D
Proportional to the cube of the wind speed
! = M / Vol
and a little algebra gives: M = ! * Vol
Now let's consider how the velocity (V) of our air parcel can be expressed. If a time T is
required for this parcel (of thickness D) to move through the plane of the wind turbine blades,
then the parcel's velocity can be expressed as V = D / T, and a little algebra gives D = V * T.
Let's make some substitutions in expression no. 1 ( KE = ! * M * V2 )
Substitute for M ( = ! * Vol ) to obtain: KE = ! * (! * Vol) * V2
!
24. Swept area
If you double the diameter
of a rotor, the swept area
is increased by a factor of
4
A 2.5 MW turbine has a
rotor diameter of
approximately 80 m
2
Swept area A = π r
28. POWER OUTPUT OF A
WIND TURBINE
The power in the wind, Pw at a given site
}
1 1 3
Pw = ρ Au = ρ A ∫ {u ( z )} p ( u )du
3
2 2
where:
u(z) =
wind speed at hub height
p(u) =
wind frequency distribution
The average output power Po of a turbine
1 3
Po = η ρ A ∫ CP ( λ ) {u ( z )} p ( u )du
2
32. WIND FARM’s
Accurate wind data for a period of time is essential
}
Mountainous regions and coasts are ideal as well as exposed
plains
33. WIND FARM’s
Accurate wind data for a period of time is essential
}
Mountainous regions and coasts are ideal as well as exposed
plains
34. WIND FARM’s
Accurate wind data for a period of time is essential
}
Mountainous regions and coasts are ideal as well as exposed
plains
Wind turbine spacing should be of the order 5D → 10D
35. WIND FARM’s
Accurate wind data for a period of time is essential
}
Mountainous regions and coasts are ideal as well as exposed
plains
Wind turbine spacing should be of the order 5D → 10D
36. WIND FARM’s
Accurate wind data for a period of time is essential
}
Mountainous regions and coasts are ideal as well as exposed
plains
Wind turbine spacing should be of the order 5D → 10D
Wind farms will experience array loss, i.e. an array of
turbines will not produce as much power as if they potentially
could
37. WIND FARM’s
Accurate wind data for a period of time is essential
}
Mountainous regions and coasts are ideal as well as exposed
plains
Wind turbine spacing should be of the order 5D → 10D
Wind farms will experience array loss, i.e. an array of
turbines will not produce as much power as if they potentially
could
38. WIND FARM’s
Accurate wind data for a period of time is essential
}
Mountainous regions and coasts are ideal as well as exposed
plains
Wind turbine spacing should be of the order 5D → 10D
Wind farms will experience array loss, i.e. an array of
turbines will not produce as much power as if they potentially
could
Low wind shear reduces the differential loading on turbine
blades, i.e. fatigue loading
40. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
41. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
42. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
Electromagnetic interference and noise
43. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
Electromagnetic interference and noise
44. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
Electromagnetic interference and noise
End of Service Life - recyclability
45. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
Electromagnetic interference and noise
End of Service Life - recyclability
46. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
Electromagnetic interference and noise
End of Service Life - recyclability
Embodied energy
47. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
Electromagnetic interference and noise
End of Service Life - recyclability
Embodied energy
48. ENVIRONMENTAL IMPACT
& PUBLIC ACCEPTANCE
}
Natural scenery and preservation of wildlife particularly
avian
Electromagnetic interference and noise
End of Service Life - recyclability
Embodied energy
Remote regions - access and grid connections
49. Advantages Disadvantages
Prime fuel is free Risk of blade failure (total destruction of
installation)
Infinitely renewable Suitable small generators not readily
available
Non-polluting unsuitable for urban areas
In Ireland the seasonal variation matches Cost of storage battery or mains
electricity demands converter system
Big generators can be located on remote Acoustic noise of gearbox and rotor
sites including offshore blades
Saves conventional fuels Construction costs of the supporting
tower and access roads
Saves the building of conventional Electromagnetic interference due to
generation blade rotation
Diversity in the methods of electricity Environmental objections
generation
Editor's Notes
\n
\n
\n
\n
Simple, single cell atmospheric convection in a non-rotating Earth.  "Single cell" being either a single cell north or south of the equator.\nTo begin, imagine the earth as a non-rotating sphere with uniform smooth surface characteristics. Assume that the sun heats the equatorial regions much more than the polar regions. In response to this, two huge convection cells develop. An intermediate model: We now allow the earth to rotate.  As expected, air traveling southward from the north pole will be deflected to the right. Air traveling northward from the south pole will be deflected to the left.\nHowever, by looking at the actual winds, even after averaging them over a long period of time, we find that we do not observe this type of motion.  In the 1920’s a new conceptual model was devised that had three cells instead of the single Hadley cell.  These three cells better represent the typical wind flow around the globe.\nRefer to source for this slide and following 3 - http://www.ux1.eiu.edu/~cfjps/1400/circulation.html\n
Global winds shape the Earth's climate, determining - in broad strokes - which areas are tropical, desert, or temperate. Here's a simplified overview of how it works.\n\nThe Sun heats the Earth most intensely in the tropical zone around the equator. The heated air rises, cools, and then dumps its moisture as rain. That's why there are rain forests in the tropics.\n\nThe now drier air is forced by the continuously rising equatorial air to move towards the temperate latitudes on either side of the equator. At roughly 30° N and S - called the "horse latitudes" - it can move no further due to the Earth’s rotation, and settles to the surface. \n\nAs the air sinks, it compresses and warms, creating hot, rain-free conditions. \nThis circulation pattern, called a Hadley cell, is why the deserts of the world are located just poleward of the tropics, to the north and south.\n\nSource - http://blogs.edf.org/climate411/2008/01/14/global_winds/\nHorse Latitudes Around 30°N we see a region of subsiding (sinking) air.  Sinking air is typically dry and free of substantial precipitation. Many of the major desert regions of the northern hemisphere are found near 30° latitude.  E.g., Sahara, Middle East, SW United States.\nDoldrums Located near the equator, the doldrums are where the trade winds meet and where the pressure gradient decreases creating very little winds.  That's why sailors find it difficult to cross the equator and why weather systems in the one hemisphere rarely cross into the other hemisphere.  The doldrums are also called the intertropical convergence zone (ITCZ).\n
These give rise to and westerlies. Trade winds occur between 0 and 30 degrees latitude, westerlies lie between 30 and 60 degrees - where Ireland lines. \n\nThe trade winds are so named as they carried the Spanish and Portuguese conquerors west to the Americas and they then returned using the westerlies to bring them back east with their heavily laden ships.\n\nCoriolis Force - Once air has been set in motion by the pressure gradient force, it undergoes an apparent deflection from its path, as seen by an observer on the earth. This apparent deflection is called the "Coriolis force" and is a result of the earth's rotation. http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/crls.rxml\n\n
Owing to the tilt of the Earth's axis in orbit, the ITCZ will shift north and south.  It will shift to the south in January and north in July.\nThis shift in the wind directions owing to a northward or southward shift in the ITCZ results in the monsoons.  Monsoons are wind systems that exhibit a pronounced seasonal reversal in direction.  The best known monsoon is found in India and southeast Asia.\nWinter -- Flow is predominantly off the continent keeping the continent dry.\nSummer -- Flow is predominantly off the oceans keeping the continent wet.\nMonsoons happen not only in southeast Asia and India, but also in North America.  They are responsible for the increased rainfall in the southwest US during the summer months and the very dry conditions during the winter months.\n\n
Owing to the tilt of the Earth's axis in orbit, the ITCZ will shift north and south.  It will shift to the south in January and north in July.\nThis shift in the wind directions owing to a northward or southward shift in the ITCZ results in the monsoons.  Monsoons are wind systems that exhibit a pronounced seasonal reversal in direction.  The best known monsoon is found in India and southeast Asia.\nWinter -- Flow is predominantly off the continent keeping the continent dry.\nSummer -- Flow is predominantly off the oceans keeping the continent wet.\nMonsoons happen not only in southeast Asia and India, but also in North America.  They are responsible for the increased rainfall in the southwest US during the summer months and the very dry conditions during the winter months.\n\n
Owing to the tilt of the Earth's axis in orbit, the ITCZ will shift north and south.  It will shift to the south in January and north in July.\nThis shift in the wind directions owing to a northward or southward shift in the ITCZ results in the monsoons.  Monsoons are wind systems that exhibit a pronounced seasonal reversal in direction.  The best known monsoon is found in India and southeast Asia.\nWinter -- Flow is predominantly off the continent keeping the continent dry.\nSummer -- Flow is predominantly off the oceans keeping the continent wet.\nMonsoons happen not only in southeast Asia and India, but also in North America.  They are responsible for the increased rainfall in the southwest US during the summer months and the very dry conditions during the winter months.\n\n
Owing to the tilt of the Earth's axis in orbit, the ITCZ will shift north and south.  It will shift to the south in January and north in July.\nThis shift in the wind directions owing to a northward or southward shift in the ITCZ results in the monsoons.  Monsoons are wind systems that exhibit a pronounced seasonal reversal in direction.  The best known monsoon is found in India and southeast Asia.\nWinter -- Flow is predominantly off the continent keeping the continent dry.\nSummer -- Flow is predominantly off the oceans keeping the continent wet.\nMonsoons happen not only in southeast Asia and India, but also in North America.  They are responsible for the increased rainfall in the southwest US during the summer months and the very dry conditions during the winter months.\n\n
\n
\n
The geostrophic winds are largely driven by temperature differences, and thus pressure differences, and are not very much influenced by the surface of the earth. The geostrophic wind is found at altitudes above 1000 metres (3300 ft.) above ground level. \n\nThe geostrophic wind speed may be measured using weather balloons. \n\nLand masses are heated by the sun more quickly than the sea in the daytime. The air rises, flows out to the sea, and creates a low pressure at ground level which attracts the cool air from the sea. This is called a sea breeze. At nightfall there is often a period of calm when land and sea temperatures are equal. At night the wind blows in the opposite direction. The land breeze at night generally has lower wind speeds, because the temperature difference between land and sea is smaller at night. \n\nOne example is the valley wind which originates on south-facing slopes (north-facing in the southern hemisphere). When the slopes and the neighbouring air are heated the density of the air decreases, and the air ascends towards the top following the surface of the slope. At night the wind direction is reversed, and turns into a downslope wind.\n \nIf the valley floor is sloped, the air may move down or up the valley, as a canyon wind. \n\nIf the valley is constricted this can further increase the wind speed.\n\nWinds flowing down the leeward sides of mountains can be quite powerful: Examples are the Foehn in the Alps in Europe, the Chinook in the Rocky Mountains, and the Zonda in the Andes. \nExamples of other local wind systems are the Mistral flowing down the Rhone valley into the Mediterranean Sea, the Scirocco, a southerly wind from Sahara blowing into the Mediterranean sea. \n
Interannual –longer than 1 year variations - can have a large effect on the overall performance of a wind farm during its lifetime. Meteorologists reckon it takes 30 years of data to determine long term values and 5 years data is needed to arrive at a reliable wind speed for a site. However 1 years data is sufficient to predict long term seasonal mean wind speeds within 10% and 90% confidence.\nUp to 25% variation can occur in inter annual wind speeds\n\nAnnual Significant variation in seasonal or monthly averaged wind speeds are common thro out the world “march – in like a lion and out like a lamb”... In Ireland the winter is much windier than the summer\n\nDiurnal – daily time scale - sea breezes and valley winds are an example of these . Generally the diurnal variation is much greater in the summer than in the winter – due to solar radiation.\n\nShort term variations include turbulence and gusts, any wind speeds that have a period between less than one second to 10 minutes and have a stochastic nature are considered to be turbulent. A gust is a discrete event within a turbulent air flow, and has measureable characteristics such as amplitude, rise time, max gust variation and lapse time\n
Interannual –longer than 1 year variations - can have a large effect on the overall performance of a wind farm during its lifetime. Meteorologists reckon it takes 30 years of data to determine long term values and 5 years data is needed to arrive at a reliable wind speed for a site. However 1 years data is sufficient to predict long term seasonal mean wind speeds within 10% and 90% confidence.\nUp to 25% variation can occur in inter annual wind speeds\n\nAnnual Significant variation in seasonal or monthly averaged wind speeds are common thro out the world “march – in like a lion and out like a lamb”... In Ireland the winter is much windier than the summer\n\nDiurnal – daily time scale - sea breezes and valley winds are an example of these . Generally the diurnal variation is much greater in the summer than in the winter – due to solar radiation.\n\nShort term variations include turbulence and gusts, any wind speeds that have a period between less than one second to 10 minutes and have a stochastic nature are considered to be turbulent. A gust is a discrete event within a turbulent air flow, and has measureable characteristics such as amplitude, rise time, max gust variation and lapse time\n
The Griggs-Putnam Index of Deformity is an additional useful tool to help determine the potential of a wind site. The idea is to observe the area’s vegetation. A trees shape, especially conifers or evergreens, in often influenced by winds. \n\nStrong winds can permanently deform the trees. This deformity in trees is known as “flagging”. Flagging is usually more pronounced for single, isolated trees with some height.\n\nThe Griggs-Putnam diagram, like the Wind Resource Maps, can offer a rough estimate of the wind in your area. The more information that you can obtain from the various sources, the greater degree of accuracy you will have in determining your wind speed and your potential power output.\n\nThe Griggs Putnam index should be used with a degree of caution, don’t just depend on one tree, make sure there are several used in the survey. \n\nConifers give better indications that broadleaf trees.\nAbsence of deformation doesn’t necessarily rule a site out of contention \n
“Data from the wind monitoring site is essential for determining the viability of the project and, particularly, for assessing financial viability. Problems with the quality of wind data can lead to significant difficulties in obtaining financing. The importance of paying attention to this cannot be over-stated. It is hard to overemphasise how easy it is to acquire bad data. A significant effort is required to ensure good data.” - IWEA best practice guidelines 2008 state:\n\nThe best way of measuring wind speeds at a prospective wind turbine site is to fit an anemometer to the top of a mast which has the same height as the expected hub height of the wind turbine to be used. This way one avoids the uncertainty involved in recalculating the wind speeds to a different height. \n\nBy fitting the anemometer to the top of the mast one minimises the disturbances of airflows from the mast itself. If anemometers are placed on the side of the mast it is essential to place them in the prevailing wind direction in order to minimise the wind shade from the tower. \n\nPlanning and Development Regulations 2008 (S.I. No. 235 of 2008), state that for; The erection of a mast for mapping meteorological conditions.\n1. No such mast shall be erected for a period exceeding 15 months in any 24 month period.\n2. The total mast height shall not exceed 80 metres.\n3. The mast shall be a distance of not less than:\n(a) the total structure height plus:\n(i) 5 metres from any party boundary,\n(ii) 20 metres from any non-electrical overhead cables,\n(iii) 20 metres from any 38kV electricity distribution lines,\n(iv) 30 metres from the centreline of any electricity transmission line of 110kV or more.\n\n(b) 5 kilometres from the nearest airport oraerodrome, or any communication, navigation and surveillance facilities designated by the Irish Aviation Authority, save with the consent in writing of the Authority and compliance with any condition relating to the provision of aviation obstacle warning lighting.\n\n4. Not more than one such mast shall be erected within the site.\n5. All mast components shall have a matt, nonreflective finish and the blade shall be made of material that does not deflect telecommunications signals.\n6. No sign, advertisement or object, not required for the functioning or safety of the mast shall be attached to or exhibited on the mast.\n
This formula is a derivative of the kinetic energy formula we looked at in the first lecture, \nK.E. = ½ m v2\n\nAir at 1,500 meters (5000 ft) could be expected to be 15% less dense than normal air\nAir at 30 degrees C would be about 5% less dense than normal air\n\nAir density normally taken to be 1.225 kg/m^3 at 15 deg C and at sea level\nAir density is affected by\nAltitude - Air density decreases as altitude increases\nTemperature - Air density decreases as temperature rises\nHumidity - Air density decreases with increases slightly with increased humidity\n
Nothing tells more about a wind turbine’s potential for generating electricity than its swept area. Invariably a turbine with a large rotor will generate more electricity than one with a smaller rotor.\n\nLooking at the example in the first lecture 20 m rotor in 12m/s winds. If we doubled the swept area to 40 meters, there would be a corresponding increase of 4 times the power available from the wind.\n
There are additional requirements for overspeed protection, particularly when there is a reduction in the turbines electrical load during operation at high tip speed ratios in high winds. \n\nYaw control is the simplest method of achieving power control, i.e the turbine is turned out of the wind direction and its blades are orientated parallel to the wind. The wind vane located above the nacelle provides wind directional information which forms an input to the control system which in turn rotates the turbine via its yaw control mechanism if necessary. \n\nActive pitch control is more common in variable speed turbines. In this case the the turbine is run at constant speed, however the angel of attack is altered to reduce the lift, thereby altering the lift:drag ratio.\n\nImage source: http://www.popsci.com/content/next-gen-wind-turbine-examined\n
There are additional requirements for overspeed protection, particularly when there is a reduction in the turbines electrical load during operation at high tip speed ratios in high winds. \n\nYaw control is the simplest method of achieving power control, i.e the turbine is turned out of the wind direction and its blades are orientated parallel to the wind. The wind vane located above the nacelle provides wind directional information which forms an input to the control system which in turn rotates the turbine via its yaw control mechanism if necessary. \n\nActive pitch control is more common in variable speed turbines. In this case the the turbine is run at constant speed, however the angel of attack is altered to reduce the lift, thereby altering the lift:drag ratio.\n\nImage source: http://www.popsci.com/content/next-gen-wind-turbine-examined\n
There are additional requirements for overspeed protection, particularly when there is a reduction in the turbines electrical load during operation at high tip speed ratios in high winds. \n\nYaw control is the simplest method of achieving power control, i.e the turbine is turned out of the wind direction and its blades are orientated parallel to the wind. The wind vane located above the nacelle provides wind directional information which forms an input to the control system which in turn rotates the turbine via its yaw control mechanism if necessary. \n\nActive pitch control is more common in variable speed turbines. In this case the the turbine is run at constant speed, however the angel of attack is altered to reduce the lift, thereby altering the lift:drag ratio.\n\nImage source: http://www.popsci.com/content/next-gen-wind-turbine-examined\n
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Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Site selection for the wind farm requires that accurate wind data over a period of time is available. Experience has shown that an average wind speed > 6 m⋄s-1 indicates a good location. Ideally, mountainous areas (assuming that access is not an issue) and coastal regions are good candidates for locating a wind farm. However, consideration should also be given to losses that may occur in the cabling from wind farm to the electrical grid. \n\nSpacing between wind turbines is a critical issue. Typical spacing should be in the region of 5D → 10D (D being diameter) between each turbine, thereby allowing for the wind to have regained speed and avoid turbulence. Greater turblance intensity reduces the spacing but increases the fatigue loading on the turbines. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n
Wind turbines and farms can have an adverse impact on the society and the environment. They can spoil areas of natural beauty and affect wildlife. The land area required for wind farms is another concern, however, the land between each turbine can be used of grazing and other farming needs provided access is available and a small exclusion area around the base of the turbine is provided. \n\nThey also can cause electromagnetic interference which affects radar and telecommunications. Noise is another area of concern, however improvements have been made in the blade design to help reduce this. \n\nWhen a turbine has reached its end of service life, it most be disposed of. Established disposal and recycling procedures can be utilised for the metallic parts, however the disposal of the rotor blades consisting of glass reinforced polymers can pose difficulties. \n\nWind turbines reduce CO2 emissions by providing an alternative to fossil fuels. It is also important to stress however that wind turbines do produce CO2, during there manufacture and disposal. Also the construction of turbines in remote regions can affect local communities, the environment, require specialised construction equipment and most also be connected back to the Grid. \n