Thursday, December 27, 2012

DnD Characters

These are links to character sheets for the campaign
  1. Dan the Dragon Adept
  2. Andy
  3. Nick
  4. Natasha

Sunday, December 23, 2012

DnD Forgotten Realms description

The following is a map and description of regions in the Forgotten Realms.

Political Maps

Trade Map

  • Anauroch
    • A desert wasteland currently occupied by two main peoples
      • Bedine
        • group of nomadic barbarians
      • Shadovar
        • The last remaining Netherese
        • Citizens of the floating city of Shade

    • History
      • This is the location of the ancient civilization Netheril. During this time the power of human mages was at its highest, and the display of their might was characterized by their floating cities. The 

DND Campaign

Towers Campaign a campaign hosted on roll 20 listed here: campaign

The following is a collection of materials related to a forgotten realms dnd campaign, to be run sometime in the future
  1. Premise
  2. Maps/Setting
  3. Character Sheets

DND Campaign Intro

Campaign Backstory

Once again a time of troubles has hit the land of Faerun, though perhaps not The Time of Troubles where the gods fell from their place in the heavens. In Evereska, the last home of the elves on the mainland, the elf Galaeron and his tomb wardens encountered a group of human crypt breakers in the tombs of their Vyshanti elders. The humans were from Vaasa, nobles of the granite tower, wielders of the darkblades and servant to Telamont Tanthul, a netherese arcanist from the city of shade. Although these humans were breaking into the ancient elven crypts, they were not after the jewels and riches hidden in the tombs. They brought along a beholder, and were using its disintegration rays to dig deeper into the walls of one of the ancient tombs, to reveal the Sharn Wall.

The Sharn Wall is an ancient work of magic erected by the Netherese, along with the help of the Sharn, a relatively unknown race of sorcerers. The Netherese are citizens of Netheril, the greatest and most powerful civilization of human wizards. They were famous for using their magic to create floating cities by severing the top of mountains and inverting them to build their floating cities. Near the end of Netheril's reign, they fought against an enemy called the Phaerimm, a race of floating wormlike creatures armed with powerful magic, the ability to eat magic, and the ability to spawn their young by implanting their eggs within their victims. They came from the outer planes, and are one of the most deadly invaders Faerun had to face in its entire history.

The most powerful mage of the time Karsus wanted to end the war between the Phaerimm and Netherese as neither side could gain a definitive advantage over the other, and as time went on, the Phaerimm were draining the life out of the earth where Netheril stood. Karsus in his hubris could not bear this blemish on the land that he owned, and decided to gain control over all magic in the world to use to eradicate all Phaerimm simultaneously. Due to his power he actually succeeded and wrested control of the weave of magic from Mystryl the goddess of magic at the time. However, he could not handle the influx of information and did not have the control necessary to direct his new powers, resulting in the fall of the Netherese cities. The Phaerimm now held an advantage but with the help of the Sharn and the new goddess of magic Mystra, the remaining Netherese were able to lock the phaerimm behind the Sharn Wall, in the Plane of Shadow. However, this was where the last functioning city of Netheril fled to. Shade, the city of shadow arcanists, fled to the plane of shadow right before Karsus caused the fall of Netheril. However, they were also locked behind the Sharn Wall with the Phaerimm in the plane of shadow, destined to fight for against its denizens for all eternity.

Through what is thought to be a misunderstanding, a magic missile from Galaeron and a bolt of shadow magic from Telamont, mixed together which caused a breach in the Sharn wall. This allowed a few phaerimm to escape, and the pride of the elves caused them to underestimate what was necessary to push them back. Soon more Phaerimm escaped, and Evereska is now in a full scale war. All active Chosen of Mystra have been called to help deal with this threat, with only a few exceptions. Elminster Aumar is now missing, due to an accident involving the princes of the city of Shade, Elminster was forced to fix a rift to hell caused by yet another blending of shadow and pure arcane magic. He was unable to seal the rift from Faerun, and is now lost in Avernus the first of the 9 hells. The Simbul Witch Queen of Algarond is likewise missing, as she searches for her consort Elminster. Sylune, the witch of Shadowdale, remains dead. Qilue, servant to Elistraee goddess of the the good aligned Dark elves, as well as Chosen of Mystra is busy protecting her temple in Undermountain, as the disappearance of Halaster Blackcloak, archmage and creator of Undermountain, caused a lack of stability in the region. All other chosen, from the Seven sisters, as well as Khelben Arunsun are now dealing with the threat of the Phaerimm in Evereska.

Campaign Introduction

Without the help of the most powerful mages, the harpers are lacking the resources necessary to keep track of events in Faerun. One such harper is the archmage of the seelie courts, Torden Kane. Kane noticed that there appears to be some coordinated events that could have disastrous results to the future of Faerun. To deal with this, he has created a chamber in his castle that utilizes an inverted version of planar binding to summon powerful beings of the material plane in Faerun to his own demiplane, which he then binds to his service using a powerful geas. This allows him to investigate these events without using his time as he is also aiding in the defense of Evereska.

This chamber currently has 5 summoning circles that are active at any given time. The current summoning has hooked a bard/priest, a dragonfire adept, a disciple of dispater, and a knight with his squire. An image of Kane appears in front of them, and commands them using a geas.
"Heroes and villains head my command, I order you to investigate the city of Darmshall in Vassa. On an outlying farm, a well now appears to be a spring of healing. One day there was barely enough water to distribute among the folk, the next clear water gushed from the spring, and those who drank from it were healed of aches and pains. Upon hearing of this, the necromancer Persephone, has launched an undead assault on the citizens of this village. Assess and deal with the situation as best you can and you'll be free from my geas."

"The enemies we face acts together in concert. Regardless of your differences, you must work together to overcome them and preserve the future of Faerun as the threat behind this events and others like it threaten everyone, from the Knights of Tyr to the servants of Asmodeus. To increase your coordination, my attendant will lead you to a room where you will test yourselves against my apprentices. Should you succeed in defeating them you will be transported to the outskirts of Darmshall to begin your mission."

You are standing in a large room made entirely out of ice. The circles that summoned and bound you lie at your feet. Immediately to your left is an icy wall marked with 5 glyphs which all appear to have activated, followed by a series of doors to some small rooms. To your right are windows that show a curious environment. You appear to be in a valley about 2 miles wide that is half covered in ice and darkness, that is separated from the other half by a river. Across the river lies an extremely bright area covered in trees. In front of you about 50 feet down is a large door, behind you is a stone wall. A hound sits idly by appearing to wait for your instructions.

Saturday, December 8, 2012

Textbook Notes ToC

The following are links to my notes on a variety of textbooks.

Sustainability Ethics Tanenbaum
The above are notes on an ethical approach to sustainability. The above are notes I've written on Tanenbaum's Computer Networks.
Wind Turbine Technology Farlow
The above are notes on Farlow's PDE for Scientist and Engineers The above are notes on an introduction to Wind Turbines
Intro to Smart Grid Cloud Applications and Architecture
The above are notes for a class on an introduction to the Smart Grid The above are notes for a book on cloud applications and architecture
Introduction to Cryptography with Coding Theory
The above are notes for Cryptography

Trivia - A Google a Day LXV

Where does the general of the Venetian army smother his wife in Shakespeare's tragedy "Othello"?
In Their Bed

What treaty ended the war that had been incited by the assassination of Archduke Franz Ferdinand?
Treaty of Versailles

What bird, whose name has come to be synonymous with "stupid", was made extinct in less than 100 years by virtue of the destruction of its habitat?

What implement does Ms. Williams use to stab herself and frame her friend with in Arthur Miller's allegorical play about hysteria in America?
A Needle

What is the only bird that is able to swim but unable to fly?

In what county is the lowest point in the United States?

What was the relationship of the winner of the 2009 Oscar for Best Director to the nominee for "Avatar" in the same category?

Which former NBA player legally changed his first name on the first anniversary of John Lennon's death?
World B. Free

Which former MLB big hitter was born on the exact same day as the professional wrestler known as "Disco Inferno"?
Sammy Sosa

Which former Commissioner of Baseball had a son who has been nominated for an Academy Award?
A. Bartlett Giamatti

Friday, December 7, 2012

Trivia - A Google a Day LXIV

What is it called when a solid becomes a gas without first passing through the liquid phase of matter?

The name of the capital of what country likely comes from the name of the son of Ptolemy, who rebuilt the city in the 3rd century B.C.?

Which of the Beatles' album covers was designed and created by the band's longtime friend, Klaus Voormann?

Greg Maddux won four consecutive Cy Young Awards in the 1990's playing for the Atlanta Braves and which other team?
Chicago Cubs

Whom did George Lucas pick for the role of Indiana Jones, though a TV contract forced the actor to bow out?
Tom Selleck

What popular science author wrote a bestselling book in 1980 with thirteen illustrated chapters that later became thirteen episodes of a popular TV show about the cosmic world?
Carl Sagan

Who is the president of the entire star system according to Douglas Adams' 1979 novel?
Zaphod Beeblebrox

What appears over the body of each dead sailor and animates the bodies on the mariner's ship described in Coleridge's addition to "Lyrical Ballads"?

Which former NHL player and now head coach shares his name with an Eisner Award-winning graphic novelist?
Joe Sacco

When J.K. Rowling vetoed Chris Columbus' non-British pick for the lead in "Harry Potter and the Sorcerer's Stone", what movie did the young actor then star in?
Lemony Snicket's A Series Of Unfortunate Events

Practice Schedule 1

Practice Schedule

Sunday Monday Tuesday Wednesday Thursday Friday Saturday
# of Arrows Shot N/A N/A N/A N/A 0 90 126
Indoor round score N/A N/A N/A N/A 0 N/A
Miles Ran N/A N/A N/A N/A 0 1/4 1/2
Push Ups N/A N/A N/A N/A 0 20 20
Crunches N/A N/A N/A N/A 0 40 40
SC Ladder Games N/A N/A N/A N/A 2 3 1
LoL Matches N/A N/A N/A N/A 0 0

Thursday, December 6, 2012

Paper - Sustainability Agenda

Sustainability Agenda

        What is the most important thing engineers can do to help realize a sustainable energy future? The most important role is for engineers to provide their services in different areas and professions. They should spread their influence through the sectors of politics and management in order to help companies and the rest of the nation realize what sustainability entails. Although spreading information allows for people to make informed rational decisions, what is more effective is when someone who already has that information is put in a position that can promote a sustainability agenda.

        First we must address the concept of rationality. Rational decisions involve complete knowledge of the situation and making a choice based on the most benefits and least disadvantages. One of the most common obstacles to this is simply that the general population on average isn’t informed about topics and issues, in this case sustainability. There are multiple ways to approach this. The first way is best handled by educators, which is to teach the subject. This is the most direct way to address the problem which is to directly tell people about it and help them learn about the subject. This is a huge role and vital to the sustainability cause however, it is not the primary role of the engineer. They’re not put in a position where they can influence change by teaching the next generation, but they can educate their coworkers and other members in the workplace.

        Currently there are restrictions built into the social structure of the workplace. In general, most engineers do not get to make high level decisions. Level refers to the level of design that the engineer is operating at. Low level design is where the majority of engineers work, which is on a small component of the overall project, for example managing tcp/ip or udp connections in computer networking. An upper level design for the same project would be something like working on the application skype and detailing how it groups multiple people into one phone call. This would be an upper level design specification or project. More computer engineers are required for the low level design and maintenance of the program, and fewer are needed for the upper level decisions. Those high level decisions are generally reserved for the more experienced employees in the field.

        However, since sustainability is a recent concern, the experienced employee’s in the workplace don’t have the same focus in their education on these kind of ethical and long term concerns. Thats why it’s important for newcomers to all fields of engineers to be more vocal about sustainability. In the workplace, there are often forums and associations where engineers can talk and share concerns about a project. Normally this involves meeting tight constraints on time to market, or on fulfilling design specifications. However, it’s important for sustainability to become worked into the main components in the design process rather than as an afterthought. New engineers must have the courage to try and promote sustainability to management and higher level engineers who can influence policy on those levels.

        The other way is simply to be in those positions with a modern engineering background. Engineers who have been trained to think in terms of sustainability have to take an active role to control those upper level decisions that are usually reserved for senior members and management. This is simply a matter of time as engineers progresses in their career, they are able to gain more influence over projects as well as climb up the corporate ladder. The reason this is a necessary step beyond simply trying to inform upper management is because of an issue pointed out in The Ethics of Sustainable Resources by Donald Scherer. The current management is already set in their ways. They are already in a high position and often wealthy, so they are buffered from economic shocks and will be among the last people to feel the effects of the sustainable energy crisis because they can buy their way out of issues. This means that the main way to make your voice heard, is to put yourself in a position of power. This allows for the company to head in a sustainable direction because you have the training and access to information to make good rational decisions about the subject of sustainability.

        Another area where engineers need to make their voice heard is in the political sphere. Most politicians aren’t qualified to speak on scientific and mathematical matters because their background did not include that training, since they mostly consist of political science or law majors. Engineers on the other hand have the training and judgement to analyze scientific and mathematical data which is necessary to properly discuss sustainability issues.

        Luegehnbiehl in his article on Ethical Principles for Engineers in a Global Environment lays out foundational principles of engineering ethics which give us reasons why it is necessary for engineers to put themselves on the political field. The principle of engineering competence say that engineers should strive to carry out work that they are capable of. In this case it is dangerous to let those with a pretense of knowledge rather than formal training make decisions about a subject they aren’t qualified to debate about. This means that we need some engineers to extend themselves beyond their own fields in order to exert their influence on different sectors in society to properly promote a sustainability agenda.

Paper - Ethical Motivation for Sustainability

Ethical Motivation for Sustainability

        The engineering profession holds a large amount of responsibility to promote sustainability because of both the knowledge and skills engineers have. Engineering transforms our raw materials into usable products, which means that it’s responsible for consuming the vast majority of our resources. Engineers are some of the few people aware of what goes on in the process of manufacturing, and their possible consequences. Therefore that knowledge binds them by duty to be responsible for both the direct and indirect consequences of their actions.

        Why should engineers care about sustainability? Here we have to establish the ideas of justice and distribution. If we care only about the present, there isn’t really any reason for engineers to concern themselves about sustainability since there are enough resources right now to be distributed among humanity to support enterprise and construction. However, this will not always be the case. Sustainability means that the rate at which we use resources is less than the rate that resource replenishes itself. Since we are using resources in an unsustainable way through the use of fossil fuels, we are facing a crisis where our civilization will eventually run out of usable resources. Estimates show that this will be sooner rather than later. This means that we have to worry about distribution of resources in a temporal way in order to preserve intergenerational justice.

        Intergenerational justice is the idea that we have an obligation to preserve the livelihood of future generations, which is an extension of the golden rule. The golden rule of ethics is the idea that we should treat others the same way that we would want to be treated ourselves, and it is found in every society on earth in one form or another. Intergenerational justice applies this not only to the people who live right now but the people who will live. If our generation uses up so many resources that it impinges on the ability for future generations to survive it would be unethical and a violation of the golden rule. A journal article Sustainability and Intergenerational Justice by Brian Barry goes over the specifics of intergenerational justice. Intergenerational justice assumes that we want progress for humanity as a whole. If we reverted to living like cavemen, sure we would solve the sustainability crisis, but it would not be just. Justice involves ensuring that quality of life of future generations is either equal or better than it is now. This is why we have to examine the engineering profession that create products and services since those items often increase quality of life.

        What role does the engineer serve in society? Alastair Gunn in his Integrity and the Ethical Responsibilities of Engineers notes that engineering is a unique profession with its own specialized concerns. Engineering projects are expected to be 100% successful, something that is not generally expected from a profession. For example, we expect that once a bridge is built it will stand and not fail. Engineers are unique in that they deal with the concerns of a large body of users, rather than singular interactions. An example of this is that a doctor visibly meets with their patients and interacts with them. On the other hand an engineer who works on a project is usually only in charge of a small aspect of it, and interacts with the user indirectly after the product has been assembled, purchased, and then used. This means that there are many layers of separation between the engineer and his end customer, which makes it difficult to see what responsibilities engineers have to society and their customers. However, the engineer must be able to live up to the expectation of 100% success with their projects, as it can often lead to disaster such as in the example case of a faulty bridge.

        So even though a single engineer can only control a particular aspect of a project, it is their role in society to make sure that projects are as successful as possible. Success in this case must adhere to the ideas of intergenerational justice in order to remain ethical because of the impact engineering has on future generations. Thus in order to live up to the role in society that is expected of them engineers must promote sustainable policies and practices.

Paper - Obstacles of Sustainability

Obstacles of Sustainability

The greatest obstacle to obtaining a sustainable energy future lies in the the organizational structure of our society in both a social and economic sense. It is currently difficult to promote new thought into our societal systems because large companies have become so established on a global scale. The central issues in design and development involve design constraints and time to market. Companies rarely take into account the long term environmental effects of their actions, which needs to become part of the normal operations of more companies. In addition, sustainability is an investment into the future, which contrasts with the in the present mindset of a market economy.

The first obstacle we need to address is the inflexibility of a market economy. In theory the free market allows for everyone to compete without governmental restrictions. This allows for products and services to freely compete letting the best service win out.  Although this seems like a system that gives everyone a fair chance at success, this isn’t always the case. The market economy is fair when a technology is in development, however it becomes inflexible once technologies have been established. Once a company becomes established, it becomes very difficult for newcomers to break into that market. 

The issues stems from capital. Older companies have more money and resources to do further research and development for their product. This means that their product will likely be better suited for its end result than a new company which limits change. Another benefit of having extra capital is that it gives the company the option to buy up smaller companies in order to reduce competition. Examples of companies that were able to achieve this kind of domination in a market are the companies Microsoft and Bell, both of which used to hold an almost complete monopoly in their respective markets. Although now this dominance has been somewhat broken, it took the intervention of the government to reduce the power of Bell Labs, and drastically different design goals to allow companies like Apple, or heavy utilization of open source products like Linux to compete with Microsoft.

This concept comes from the Theory of Innovation which states that a social system is made up of five different kinds of people: the innovators, the early adopters, the early majority, the late majority, and the laggards. In the field of sustainable energy sources for energy generation already exist with  the coal and petroleum industries, which puts us in a social system where people are mostly made of the late majority. The late majority are people who are comfortable and accustomed with existing products. Because they are already comfortable with the situation, they are resistant to change, and this includes not only the fossil fuel companies, but also their customers which includes the vast majority of the entire population. Most people already use electricity and gas in order to live in their homes and drive around for work or leisure. This means that sustainable energy, is in that difficult stage where the market is normally unfriendly towards it as well as having to deal with competition from large already established industries.

In order to make sustainable energy viable in the market, there has to be some kind of incentive socially and economically. The social motivation is thankfully already there, and simply needs time and effort to grow. Forms of media ranging from presentations by presidents, to books such as the post carbon reader series serve to inform the public that we are in an energy crisis and that there is a need for alternative sustainable energy sources. Heinberg’s article What is Sustainability in the post carbon reader gives us a set of axioms explaining why sustainability is necessary. His first axiom is that “Any society that continues to use critical resources unsustainably will collapse.” This points out the fact that unsustainable practices, even if you are for some reason skeptical of the effects of global warming, will still result in the loss of resources, and the potential for societal collapse because of our limited resources.

More scientific articles such as Smil’s Science, Energy, Ethics and Civilization show us the immediacy of these issues. We are already hitting the point where our consumption of resources is hitting Eath’s natural limit and can only last for about 1 or 2 more generations without change. So we know that social motivation for sustainability exists. However, why hasn’t this been effective in motivating action? The answer is twofold.

First we also need to worry about the economic aspect because in order for technologies to be implemented, someone must be able to make a profit from that technology. The issue is that since alternative energy restructures existing technology, and is still in development, the initial cost of most sustainable energy generation is much higher than conventional fossil fuel generation. A good example is electrical wind generation. Wind power has historically been so cost inefficient that generators have only been built during the years where the government gives out huge tax/rebate incentives. Whenever those incentives run out, construction immediately halts as it is no longer profitable. Although this is a more extreme case, sustainable energy has trouble becoming profitable.

Secondly, sustainability is a long term concern. In general people are concerned with their day to day activities, not what will occur 20+ years in the future, and even when we are, the scope of our concerns are usually limited to our immediate family, such as our children. Sustainability concerns the survival of humans as a race, rather than concerning the individual or their families. This means that the sheer scope of sustainability hinders most people from taking action because they are all too willing to place responsibility for that on someone else, and keep their concerns focused on their day to day lives. This is why even though there are some efforts already in place to address the social and economic problems inherent to sustainability  they still remain as the biggest challenge for the sustainability movement to overcome.

Sunday, December 2, 2012

Notes - Glossary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.

  • Abrasion - Wear in machinery between components grinding against each other
  • Active yaw - Having controlled yaw motion rather than forced motion through wind
  • Aerodynamic Force - Force exerted by moving air or gas
  • Airfoil - Profile of the outline of an airplane wing, usually having large lift coefficient and a small drag coefficient
  • Alignment - Having the axes in a straight line
  • AC - Alternating Current, type of electricity with continuously alternating direction
  • Alternator - machine generating AC electricity
  • Amplitude - instantaneous value of cyclic variable
  • Anemometer - windspeed measuring device
  • Angular speed - rotational speed of an object in radians/sec or degrees/sec
  • ANSI - American National Standards Institute
  • Arc Flash - flow of electricity outside a conductor caused by a short circuit, generates high pressure and temperature in the air
  • Arm - Part of a planetary gear that holds the planet gears together
  • Armature - Rotating part in a motor, composed of one or more windings
  • ASME - American Society of Mechanical Engineers
  • Asynchronous Generator - aka induction generator
  • Autotransformer - transformer where primary and secondary windings are part of the same winding, not isolated
  • AWEA - American Wind Energy Association
  • Backlash - free motion between two meshing gears due to noncontact free space between teeth
  • Balanced Load - When three loads in a three-phase electrical system have equal values
  • Bedplate - A main structure in a nacelle where all the components are mounted or attached
  • Betz Limit - Maximum value of a wind turbine's power coefficient. 16/27 or 0.59
  • Bevel Gear - Gears with perpendicular axes
  • Blade Pitch Control - The capability of turning a turbine blade about its axis with respect to its hub
  • Blade Root - attachement of blade to hub
  • Blade Tip - free end tip of blade
  • Bridge Rectifier - full rectifier where two sets of diodes alternatively conduct, converts AC to DC
  • Brush - part of carbon in an electric machine that slides on a conductor to allow for electricity transfer between moving components to stationary components
  • Cable Grip - Metallic device for turbine climbing
  • Capacitive Reactance - Apparent resistance due to a capacitor
  • Carabiner - Metallic device allowing connection of two rings in climbing equipment
  • Carrier - Part of a planetary gear holding gears together called arm
  • Cavitation - An interaction between metallic rotating piece and a liquid in a gearbox or pump causing erosion
  • Centrifugal force - Outward force due to rotating reference frame
  • Characteristic Curve - Curve exhibiting the main features of a device machine or equipment based on a major parameter
  • Characteristic Diagram - aka Characteristic Curve
  • Chord - Distance between leading and trailing edge of airfoil
  • Chord Line - line connecting leading and trailing edge of an airfoil
  • Collector - Point where turbine outputs in a windfarm are connected before being sent to grid
  • Compound Interest - Periodically increased interest
  • Cone Angle - angle that blades of a wind turbine make with plane perpendicular to axis of rotation
  • Corrective Maintenance - fix components after it breaks rather than preventative
  • Cost of Capital - Money spend to generate capital for investment
  • Crowbar - Set of resistors that come into operation when generator disconnects and load vanishes, prevents overspeed
  • Current - Intensity of flow of electrons in Amperes
  • Line Current - Current in supply lines of three-phase electrical system
  • Current Direction - Direction of electrons in a current
  • Cut-in Speed - minimum speed for a turbine to generate power
  • Cut-out Speed - maximum speed for a turbine to generate power
  • Darrieus Turbine - Vertical axis wind turbine looks like eggbeater
  • Delta Connection - Connects three wires of three phase electricity to a load in a triangular formation
  • DFIG - Doubly fed induction generator where the rotor is made of windings and requires slip rings to connect to electricity
  • Diode - Semiconductor with two terminals, allows one way curent
  • DC - Direct Current type of electricity that flows in one direction
  • Direct Drive Mode - Connecting a turbine and generator without a gearbox
  • Discout Rate - economic term implies rate for borrowing money
  • Dispatch System - communication system where all participants are informed
  • Distribute Generation System - Electrical system with more than one generator, typically referring to many small sets of generators as opposed to centralized larger ones
  • Downwind Turbine - Turbine where wind hits tower before blades
  • Drive Gear - transfers energy to mating gear
  • Drag - component of aerodynamic force parallel to wind that slows down movement
  • Drag Coefficient - ratio of drag force to aerodynamic force causing it
  • Drag-Type Turbine - turbine based on drag forces
  • Drive Train - set of gears to obtain desired gear ratio
  • Dynamo - Direct Current Generator
  • Efficiency - Ratio of output energy to input energy
  • Electric Circuit - setup of electrical components powered by a source
  • Electric Load - consumer of electricity
    • resistive - load that has only resistance
    • capacitive - load consists of capacitors
    • inductive - contains windings
  • Electric Source - battery or generator providing power to a system
  • Electromagnet - magnet made of coil and ferromagnetic core, requires electric power for magnetism
  • Electromechanical System - Device with both moving and electric parts
  • Energy - Potential to do work, or force applied over a distance
  • Epicyclic Gear - Planetary Gear
  • EWEA - European Wind Energy Association
  • Fall Arrest - Stopping a fall from a height
  • Fatigue - repeated tension/compression stress
  • Fatigue Failure - failure of component due to fatigue
  • Feathered - Position of wind turbine blades with smalles lift and largest drag
  • Ferrous - Iron family of metals
  • Fixed Speed Mode - Turbine speed constant operation
  • Flashing - repeated reflection of sunshine on a turbine blade
  • Flicker - Short time voltage variation in power line due to disconnect of large load
  • Flickering - Shadowing effect of rotating blade
  • Flutter - Vibration of wind turbine blade about its own axis
  • Foundation - Massive block of concrete anchoring a tower
  • Free Wheel - Standby state of wind turbine where there is insufficient wind to turn turbine
  • Frequency - Number of repetitions in one second of cyclic phenomenon
  • Frequency Converter - Device that changes frequency of AC
  • Full-Wave Rectifier - 2 rectifier diodes that converts the entire cycle of AC to DC
  • Fuse - Protection device in electrical circuit that melts to open a circuit in the case of overheat
  • Future Value - value of money at future time
  • Gearbox - mechanical device in an enclosure, converts rotational speed
  • Gear - single part of gear system, gearbox component
    • Arm - part of planetary gear that holds the planetary gears together
    • Bevel - perpendicular axes connected gear
    • Driven Gear - receives energy from mating gear
    • Driving Gear - gives energy to mating Gear
    • Epicyclic Gear - Planetary Gear
    • Helical Gear - teeth are angled with respect to shaft axis to reduce backlash
    • Idler Gear - gear that stands in between two main gears to change direction of rotation
    • Internal Gear - gear in the form of ring with teeth on the inside
    • Planetary Gear - set of gears arranged in form consisting of sun gear in the middle, usually 3 planetary gears engaging with sun gear and outer ring gear with internal teeth, can accept two input speeds, mounted on bracket that can turn independently
    • Ring Gear - outermost gear with internal teeth in planetary gear
    • Spur Gear - gear with teeth parallel to axis of rotation
    • Sun Gear - innermost planetary gear
    • Worm gear - gear with high ratio to reduce speed, axes set at 90 degrees
  • Gear Ratio - ratio between output and input speeds in a set of gears
  • Gear train - set of gears arranged to obtain a specific gear ratio
  • Generator - machine that produces electricity, mechanical to electrical
    • Armature - windings on the rotating part in a generator or motor, current carrying windings on a moving part
    • Brush - electrical connector made of carbon or carbon composite, when electrical connection between rotating and stationary parts needed, slides on metallic rotating ring
    • Rotor - rotating part of generator
    • Stator - stationary part
  • Grid - Electric Network
  • Half-wave Rectifier - Simplest type of AC to DC rectifier one diode only accounts for half the wave transferred into DC
  • Harmonics - frequencies that are multiples of the fundamental frequency
  • Harness -  part of the protective equipment or catching the wind energy by a turbine
  • HAWT - Horizontal Axis Wind Turbine
  • Hertz - frequency unit
  • High-Speed Shaft - Output shaft in a wind turbine linked to generator shaft
  • HVDC - High Voltage Direct Current transmit electricity around 300 kV DC
  • Hub - part of propeller type wind turbine to connect blades
  • Ideal Transformer - Assumed transformer with zero loss
  • IEEE - Institute of Electrical and Electronics Engineers
  • Induction Generator - AC generator where rotor current is generated by induction than connection to electricity as in the synchronous generator
  • Inductive Reactance - Apparent resistance due to an inductor
  • Inertial Force - force required for acceleration or deceleration
  • Infrasound - sound with frequency below human hearing sometimes generated by wind turbines
  • Initial Cost - startup costs of a project
  • Inverter - converts DC to AC electricity
  • Islanding - isolation of a part of AC Network from rest resulting in frequency and voltage drift
  • ISO - International Standards Organization
  • Isolation Transformer - Transformer used to separate a circuit from the main device 
  • Kilowatt - a thousand watts
  • Kilowatt-hour - measures energy consumption
  • Kinetic energy - energy associated with motion
  • Lagging - current waveform behind the voltage waveform
  • Lanyard - part of safety equipment hooked to a safe point for fall arrest, contains spring piece
  • Lattice Tower - tower made from small pieces welded together into a truss
  • Leading - current waveform in front of voltage waveform
  • Lift - perpendicular aerodynamic force to direction of wind caused by pressure differential over an object
  • Lift Coefficient - ratio of lift force to aerodynamic force causing it
  • Lift-Type Turbine - turbine based on lift instead of drag
  • Lockout - locking a dangerous device from normal use
  • Lorentz Force - Force exerted on wire carrying a current inside Magnetic Field
  • Main Shaft - low speed shaft in gearbox connected to rotor
  • Maintenance - keeping a machine in operation
    • corrective - repair after failures occur
    • preventative - systematic repair regardless of state of machine
    • scheduled maintenance - regular planned repair
  • Met Tower - Meteorological Tower
  • Motor - converts electrical energy to mechanical
  • Nacelle - A room at the top of a turbine tower that houses gearbox, generator and other equipment
  • Natural Frequency - frequency inherent to object that can resonate
  • Net Present Value - economic term represents current revenues minus the total cost over lifetime of project
  • Offshore - on a lake or sea
  • Onshore - on land
  • Operating Costs - continuous expenses necessary to run endeavor, such as rent, purchase of raw materials, maintenance
  • Operating Speed - speed at which machine normally works
  • OSHA - Occupational Safety and Health Agency
  • Output - Product or result of a machine
  • Overspeed - Speed above entire capacity potentially dangerous to machine
  • Pad Mount - transformer mounted on flat surface
  • Peak Hours - Electricity consumption peak hours
  • Permanent Magnet - Magnet that is continuous without electrical input
  • PPE - Personal Protective Equipment
  • Phase Angle - angle between voltage and current waveform, time delay
  • Phase Current - Current passing through a load between each of two lines in 3 phase system
  • Phase voltage - voltage across each individual load in 3 phase system
  • Pinion - smaller gear in a pair of gears or the output gear in drive train
  • Pitch Angle - angle blade forms in reference to rotation about its axis, alters angle of attack
  • Pitch Circle - represent gears size
  • Pitch Control - action of controlling pitch angle of blades
  • Pole Mount - transformer mounted at top of electricity distribution post
  • Power - Work done in 1 second
    • Active - Power converted to heat or work
    • Reactive - power due to capacitor or inductor storage in one part of cycle given back in next part of cycle
    • Apparent - power generator supplies for consumption
    • Coefficient - in wind turbine must be less than Betz Limit ratio of electrical generation to what is in the wind
    • Curve - Operational expected power curve
    • Factor - ratio of active power to apparent power, smaller than 1
    • Factor Correction - improving the power factor of AC currents using capacitors
    • Plant - industrial unit for generation
    • quality - degree of agreement to expected stability requirement, 50 or 60 Hz
  • PPE - Personal Protection Equipment
  • Present Value of Money - value of money expressed for a future time in today's money
  • Prevailing Wind - Most common wind direction for an area
  • Prime Mover - Source of mechanical power turns a generator
  • Propeller Turbine - Turbine with blades similar to propeller, most common type of wind turbine
  • Rectifier - converts AC to DC
  • Renewable Energy - Energy from natural sources that is recoverable
  • Reluctance Force - Force by an electromagnet trying to shorten path of magnetic field
  • Ripple - Rapid fluctuations of voltage about nominal value in DC
  • Root of a Blade - end of blade attaching to hub
  • Rotating Magnetic Field - Magnetic field rotates about an axis, exists inside the stator of AC motors, basis of their operation
  • Savonious Rotor - drag type turbine that consists of two half cylinders
  • Scuffing - transfer of metal particles by tearing and adhesion from one tooth in a gear to another by welding
  • Shadow Flicker - Moving shadow cast by rotating blade
  • Shear Stress - stress due to a cutting force
  • Sine Wave - Sinusoidal wave function
  • Single - Phase - simplest AC electricity transmitted by 2 wires
  • Skew Wind - Wind whose direction is very far off from horizontal
  • Slip - act of not rotating at synchronous speed in induction motors and generators
  • Slip Ring - metallic ring on rotor of certain types of AC machines to transfer electric current
  • Slip Speed - difference between actual rotating speed and synchronous speed
  • Smart Grid - grid equipped with automated self correcting devices
  • Solidity - percentage of solid area traced in a circular rotor motion, blade area to total area
  • Spar Platform - platform in the form of a vertical cylinder top for wind turbine
  • Squirrel-Cage Motor - induction motor without windings, consists of bars connected by two rings, cage like structure
  • Stall - decrease in lift force until drag takes over
    • Control - use of stall to regulate motion of turbine
  • Star connection - connect wires in a y shape as opposed to a triangular shape
  • Step-down - lowering voltage
  • Step-up - increasing voltage
  • Substation - electrical utility to regulate electricity before sending to grid
  • Synchronous Generator - AC generator with one or more magnets, electricity generated in stator when rotor rotates at a fixed frequency
  • Synchronous Motor - AC motor where one or more magnets is within a rotating magnetic field causing rotor to follow the field, runs at multiples of synchronous speed
  • Synchronous Speed - constant speed of electrical machine dependent on frequency of supply
  • Tagout - put note on device or location as safety precaution
  • Tension Leg Platform - floating platform kept in place by cables attached to seabed under tension
  • Three-Phase System - requires 3 wires at least, each with fixed delay between them in voltage
  • Thyristor - control transistor used in rectifiers and inverters
  • Tip Speed - speed of tip of blade
    • Ratio - ratio of tip speed to wind speed
  • Torque - turning effort about a point perpendicular to rotational motion
  • Tower - support rotor and nacelle
    • Lattice - welded small structure support
    • Tubular - singular tube or conic shape support
  • Turns Ratio - ratio between number of turns in primary and secondary windings
  • Universal Motor - Type of motor that can work with both DC and single phase AC
  • Upwind Turbine - Wind turbine where blades are in front of tower and wind reaches blades before tower
  • Variable Slip Mode - Way of operation where wound rotor induction generator used with some power extracted
  • Variable Speed Mode - Synchronous generator that can operate at different instead of singular speed
  • VAWT - Vertical Axis Wind Turbine not sensitive to wind direction changes
  • Vector - quantity with both magnitude and direction
  • Volt - Electrical potential
  • Volt-Ampere - unit of measurement used to express apparent power, when voltage and current out of phase
    • VAR - Volt Ampere Reactive - measures reactive power
  • Watt - 1 Joule per second
  • Wind Data - Statistical information gathered about wind in a region
  • Wind Farm - region of multiple wind generators also called wind park
  • Wind Vane - measures wind direction
  • Work - used energy
  • Worm gear - high gear ratio used to reduce speed, driven gear cannot force drive gear to rotate
  • WRIM - Wound rotor induction machine whose rotor contains winding instead of squirrel cage
  • Wye Connection - also called star connection
  • Yaw - action of orienting a wind turbine into direction of wind
  • Yaw Gear - gear system to rotate turbine for yaw motion
  • Yaw System - Entire gears and motors involved in Yaw motion of turbine

Saturday, December 1, 2012

Notes - Chapter 17 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Hazards
    • height
      • most serious threat, fatalities in 2008 due to falls was 700 in US
    • confined environment
    • electrical equipment
    • turbine motion
  • Accidents usually due to lack of knowledge and ignoring safety rules
    • training for safety should be provided
    • responsibility of the employer to provide safe environment
  • Safety Regulations set and monitored by authorities in each country
    • (OSHA) Occupational Safety and Health Administration
  • Safety number one
    • (PPE) Personal Protection Equipment used to reduce risk of accidents
      • must be checked periodically, i.e. yearly inspection
      • climbing gear
        • simplest includes harness to wear, cable grip, locking carabiner
      • hard hat
      • fall arrest equipment
        • lanyard with a hook to secure to a point
    • Tagout and lockout practice
      • tagout is a note to notify about dangers
      • lockout place equipment to be confiscated
    • Receive training for self rescue
    • worker learns how to rescue colleagues
  • Long sleeve shirts and pants, no unnecessary accessories

Notes - Chapter 16 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Turbine must operate in a safe state
    • clean dirt, oil and leftovers of any kind
    • account for effects in temperature
      • first components affected are gearbox and lubrication oil
    • Account for formation of ice on the blades
      • brings up hazards when the ice melts and flies off blades
      • greater during startup or shutdown
  • Subject to getting struck by lightning
    • can cause severe structural damage
    • equipped with lightning rod from tip to root
    • embed in blade structure from tip to root, connect to hub and nacelle and down tower
  • Wind turbines have the potential to be used in urban areas
    • not propeller turbines, vertical axis ones more likely
    • safe, quiet, and non obstructive, likely on the top of buildings
    • economically viable and worth endeavor

Notes - Chapter 15 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • It is important to know the possible effects on the environment
  • main reason for offshore wind farms are environmental concerns
  • Turbines
    • causes sound pollution, characterized by frequency
    • Infrasound is low frequency, not audible by humans
    • turbine is far enough that we cannot hear it, it does not have adverse sound effects
  • Obstructs View
  • Modern Turbines also constructed for aesthetics to eliminate view complaints
  • Flashing is the cyclic reflection of sunshine on turbine blades
  • Flickering is the cyclic moving shadow cast by turbine blades
  • Birds and Bats can be slain by turbine
    • less than deaths caused by house cats so not often complained
  • A wind farm must not be developed where the ecosystem of natural habitants can be disrupted
  • Wind Farms can also interfere with communications depends on the location of turbines and transmitters
  • Offshore wind turbines about 30-40 miles out to sea
    • Electricity distribution requires cables to be installed under the seabed
    • HVDC High Voltage Direct Current preferable for offshore wind farms but more expensive
    • shallow water can be fixed to seabed, deep water must be floating

Notes - Chapter 14 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Value of money is not constant due to inflation and other factors
  • In order to evaluate, net income must be calculated based on full life of the project
    • reflect all income, cost, and investment
    • Future value of money dependent on interest rate and inflation
  • Profitability important for development
  • Cost of developing wind farm has high initial and operating costs
    • initial costs are the expenses that must be paid up front
      • high in comparison to other generation sources
    • operating costs paid throughout lifetime
      • annual expenses generation and delivery operations
      • smaller in comparison to other generation, no fuel
        • proper maintenance can also reduce this price
        • preventative maintenance helps ensure more evenly distributed costs

Notes - Chapter 13 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • The wind loads on all parts of a turbine ultimately transferred to the ground
  • Each component must be strong enough to withstand their loads
    • dependent on turbine rpm, and wind
    • do not diminish when turbine is at rest, only changed
    • Aerodynamic forces are top heavy, so the blades and rotors are subject to periodic forces
    • Frequency of these forces is 3 times the speed of rotation
  • Natural frequency is an intrinsic property of any mechanical component with flexibility
    • each blade, hub structure, main shaft, tower are principle components that contribute to natural frequency
    • natural frequencies must not be able to excite one another
    • blade in particular and any other turbine components under cyclic loads are subject to fatigue
    • vibration is undesirable, causes early failure in components

Notes - Chapter 12 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Transformer is a necessary electrical device for any wind turbine
    • steps up the voltage from generator to the collector for the grid
    • Transformers either step up or step down voltage and are called as such
  • If transformer is not used to change voltage, it is used to protect a device and is called an isolation transformer
  • Ideal transformer is used for calculations, assumes no losses so output power equals input power
  • turns ratio
    • ratio of windings between winding 1 and winding 2
  • Autotransformer has only one winding for input and output, tapped for electricity at variable location
  • pad-mount transformer is mounted on flat surfaces, pole mount on poles
  • Rectifiers convert AC to DC
    • bridge rectifier, single phase or three phase
    • low power uses diodes
  • Ripples in DC is the fluctuation of voltage about a nominal value instead of being constant
  • Inverters provide AC voltage from DC source
  • Thyristor is a component used in rectifiers and inverters used for switching

Notes - Chapter 11 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Direct Current generators only used in small isolated turbines
    • Electricity can be stored in batteries
    • Direct drive is when a generator is directly connected to turbine without gearbox
  • Motor and Generator have the same structure
  • Industrial Turbines always use three-phase alternating current generators
    • Synchronous Generators
      • must operate at the synchronous speed
      • fixed speed mode and variable speed mode
    • Asynchronous Generators
      • also called an induction generator
      • squirrel cage generators, run in only one mode of operation
      • wound-rotor induction generators
        • connect to outside circuit with slip rings and brushes
        • run in variable slip mode
        • turbines with doubly fed induction generators
      • don't run at synchronous speed
        • generators must run at slightly higher speed
        • motors run at a slightly lower speed

Friday, November 30, 2012

Notes - Chapter 10 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Turbine Controller
    • Wind turbine cannot work properly without accurate controls
    • monitors safe operation of turbine
    • takes action to correct faults, change electrical loads, and manage startup and shutdown
  • Mechanical and Electrical parameters much match for the balance of power in turbine
    • Mechanical
      • rotor speed
      • torque on rotor
      • power
      • blade pitch control/pitch angle
    • Electrical Parameters
      • Voltage
      • Frequency
      • generator speed
  • Can be designed for upwind or downwind configuration
    • downwind turbines have self-alignment passive yawing
  • Modern turbines have active yawing
    • rotate nacelle with respect to the tower
    • operating characteristic curve determines the power output at each wind speed
    • look-up table in the turbine control system
  • Wind Speed measured by anemometer
  • smaller wind turbines work based on stall control
    • power capacity lowers as wind speed increases beyond certain value
  • Park position using turbine brakes

Notes - Chapter 9 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Gears are used to change the speed and torque between two shafts
    • driving shaft is the input 
    • driven shaft is the output
    • usually used as speed reducers, torque on output shaft larger than input torque
  • In wind turbines gears increase the speed of rotor to match higher speed of electric generators
  • Configurations for a pair of gears
    • Spur Gears the shaft are parallel
    • bevel gears shafts are perpendicular
    • worm gears shafts are perpendicular
  • Gears can be categorized based on the angle of the teeth with the body of the gears
    • helical gears have teeth cut an angle
  • Backlash is the free play between a pair of gears
    • optimally want to minimize
  • Planetary Gears

    • sets of gears with a particular arrangement
    • Sun Gear
      • output
    • Ring Gear
      • often stationary and doesn't rotate
    • Planet Gear
    • Arm
      • input
  • Gears can be combined in a gearbox, planetary gear combined with other gears
  • Lubrication is vital reduces friction, cooling, moves dirt and debris away
  • Alignment is also crucial
  • Damage leads to permanent failure
    • types of damage are fracture, bending, wear, fatigue, cracks, and scuffing

Notes - Chapter 8 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • P = IV
  • Loads
    • Resistive load is a load due to resistors and not dependent on frequency
    • Capacitors and Inductors exhibit frequency dependent resistance called reactance
      • Capacitive and Inductive loads act in opposite directions in phasor diagram can cancel each other's effect
      • cause phase difference between voltage and current
        • preferred value for the phase angle should be as close to zero as possible
        • power factor is the value of the cosine of phase angle
      • electric motors put both inductive and resistive loads into circuit
      • Capacitors in parallel with motors reduce inductive load
  • Current Leading Voltage, means current waveform reaches max or min value before voltage waveform
  • Power types
    • DC power corresponds to resistive load
    • AC 
      • reactive power
        • corresponds to inductive and capacitive loads
        • power stored in each half cycle and sent back to circuit
      • active power
        • resistive loads in AC
        • real power that converts heat or work
      • apparent power
        • provided to maintain a current I in a circuit of voltage V, generator provides apparent power
  • To connect turbine to a grid
    • equal voltages
    • same frequency
    • synchronized waveforms
    • have similar phase sequences
  • Turbine must not lower the power factor of grid
  • The output from all turbines in a wind farm goes to collector substation
    • raises voltage from turbines to grid
  • Power quality
    • perfect sinusoid in AC circuit
    • no fluctuations in voltage and frequency
    • variations, flickers and spikes all indicate lack of quality
  • Harmonics are low-voltage signals that are multiples of the frequency
  • Islanding when a wind farm becomes isolated from the rest of the network which can lead to a drift and voltage and frequency
  • Control actions
    • control voltage
    • control frequency
    • control available current due to power from wind

Notes - Chapter 7 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Power is proportional to force required to move it and how fast the object moves
    • can be proportional to torque and angular speed for rotational objects
  • Power grasp from wind of a turbine is affected by how fast the turbine rotates and the pitch angle of blades
    • relationship between power grasp and angular speed is not linear
  • TSR is Tip speed ratio, ratio of tip of blade speed to wind speed
    • depends on wind speed and turbine angular speed
  • Power grasp depends on power coefficient not constant for turbine
  • Turbine must operate at a speed where the power coefficient is around maximum value
  • Daily production of turbine
    • based on pattern of wind over 24 hr
    • power multiplied by time for various values of turbine power
  • Annual production is daily production multiplied by operating days while accounting for effect on density and temperature based on season

Notes - Chapter 6 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Electrical Machines
    • Generator converts mechanical energy to electrical energy
      • works based on Lorentz Force, wire moves inside magnetic field generating voltage
    • Motor converts electrical energy to mechanical energy
      • works based on Lorentz Force, current carrying wire inside magnetic field has a force exerted on it
  • AC and DC machines cannot operate interchangeably
    • DC generator connections must have same voltage
    • AC Generator connections must have same frequency, and synchronized
  • Fluid Analogy
    • Electrical voltage is a measure of the level of electricity
    • Current is a measure of the flow of electricity
    • Loads consume electricity, slow the flow, and or reduce the level
    • Source provides electricity or provides movement/flow
  • AC frequency is measured in Hz
    • North America power is provided at 60 Hz
    • European countries power is provided at 50 Hz
  • Voltages of loads and sources must match
    • Power capacity of source must be greater than the power of loads
    • Frequency of load to source must be the same
    • important for attaining required rpm for motors
  • (PM) Permanent Magnets are not often used, usually electromagnets
  • right hand rule
  • DC motor can have any acceptable rpm, AC motor can have speeds at synchronous or close to synchronous speed, dependent on frequency of electricity provided
  • generators can be connected together
  • Wind Turbines don't generate power when wind speed is below cut-in speed, and does not generate electricity over cut-out speed
    • during strong winds wind turbine can be taken out of service, stopped and brakes applied
Back to ToC

Notes - Chapter 5 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • main components of a wind turbine are
    • tower
      • newer are cylindrical, sometimes with a taper
      • older are lattice towers
    • nacelle
      • housing on the top of tower
      • provides room for gearbox, generator, and other misc components
    • rotor
      • moving part, consists of blade and hub
    • foundation
      • heavy concrete foundation to endure wind
  • Each wind turbine has a transformer to usually increase the voltage of electricity produced by generator
    • pad-mount transformer
  • All turbines have anemometer that measures direction and speed of wind
    • sometimes wind direction is detected with a separate device

Notes - Chapter 4 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Wind Turbine Types
    • Horizontal Axis
      • HAWT
      • must be yawed into the wind for max wind capture, follow wind direction
      • most common wind turbine is propeller wind turbine, works based on lift force
    • Vertical Axis
      • VAWT
      • not sensitive to wind direction
      • easier accessibility to most of the components
      • Darrieus Machine
        • weak starting torques
        • good power coefficients

      • H-Rotor
        • weak starting torques
        • good power coefficients

    • Savonius Rotor
      • drag-type turbine can be installed as either VAWT or HAWT
      • drag-type turbines have smaller power coefficients

Notes - Chapter 3 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Any object in the wind stream subject to a force from wind
    • Force an object depends on the form and size of the object
    • Force can result in torque
  • Force can be measured in pounds
    • Torque in foot-pounds
  • Forces are represented with vectors
    • force on a plate from wind depends on angle between plate and wind direction called angle of attack
    • aerodynamic forces include
      • drag
        • drag coefficient is ratio of drag force to aerodynamic force
      • lift
        • ratio of lift force to aerodynamic force
  • airfoil is a long thin object with a large lift coefficient but a small drag coefficient
    • leading edge confronts air
    • trailing edge leaves air
    • chord the width between the leading edge and trailing edge that is larger than the average thickness
    • chord line is the straight line between leading and trailing edge
    • gradual curves round leading edge, sharp trailing edge
    • low thickness to chord ratio

Notes - Chapter 2 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Energy is the potential to do work
    • any moving object has some kinetic energy
    • energy depends on mass and velocity squared
  • Flowing Fluids also contain kinetic energy
    • based on density
    • cross-sectional area
    • speed cubed
  • If in a pipe cross section restricts area, if in free moving air we define a cross section
  • Power is more meaningful than energy
    • Energy in 1sec
    • Energy is Power multiplied by time
  • Power Absorption depends on power in the wind and the power coefficient of the turbine
    • Maximum value is called the Betz Limit
    • 16/27 or 0.59
  • Wind speed is not constant
    • varies from hour to hour season to season
    • varies with height
    • wind pattern needs to be investigated
      • represented by graph
    • changes with terrain
      • top of a hill has greater wind speed than in a valley

Notes - Chapter 1 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Wind has been a source of energy since ancient times
    • Persian Windmill Vertical Axis, 1000 years old
    • Dutch Windmill Horizontal Axis, built in 12th century
  • Early wind turbines much smaller than modern turbines
    • 4 MW
  • Earth has limited resources that must be balanced
  • Sufficient wind energy in the world to power everything but has difficult to use energy load
    • wind turbines have small production capability
    • requires smart grid to allow electric network to compensate for any additional loads or additional production
  • Electric Energy measured in KW hours
    • CO2 generated .712 kg per kw-hr
  • Wind development requires good wind profiling
    • wind speed increases with height

Notes - New and Future Technologies

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • energy must be able to transmitted
  • dispatch system
    • communication by radio fax to all participants
    • inform nodes about levels of production
  • peak hours
    • highest consumption hours
    • schedule production based on consumption patterns
  • distributed generation systems
    • many smaller power plants rather than singular large power plants
    • smart grid
      • controlling load and production efficiently through managing distributed systems
      • automated controls and supervising

Notes - Wind Turbine Siting

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • siting is the evaluation of a site for wind turbines and development
    • wind resource map not enough quality of wind
    • quality of wind depends also on topography and altitude
  • class of wind
    • also have to worry about frequency of wind storms or hurricanes

wind class wind speed(m/sec) wind speed(mph)
Marginal 5.6-6.4 12.4-14.3
Fair 6.4-7.0 14.3-15.7
Good 7.0-7.5 15.7-16.8
Excellent 7.5-8.0 16.8-17.9
Outstanding 8.0-8.8 17.9-19.7
Superb 8.8-11.1 19.7-24.8

Notes - Wind Farm Development

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • wind farm sometimes called wind park
    • equivalent of power plant
    • area with large number of turbines
  • have to scope area collect wind data
    • metrological data
      • met tower to collect data, vary in height form 10-70m
      • studies roughly around 3 years unless historical data can be drawn
    • verify transmission line
    • coordinate with local authorities
    • perform soil studies to ensure foundation engineering
  • due to cost of studies often built with tax breaks

Notes - Technical Issues

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • disadvantages of wind energy
    • low level energy not high capacity
      • requires a lot of land area
      • wind power ratings are for maximum power delivery
      • expected max power only about 1/3rd of the day
    • not continuously available
    • wind cannot be the full supplier of energy for the grid in the US but is possible in other more windy countries
      • transmission line technology in many of these countries not capable of supporting variable energy flows from wind energy

Notes - Importance of Renewable Energy

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Earth has limited energy resources
  • ancient times, number of people small, pollution unnoticeable, plant growth rate renewed energy resources
  • modern times
    • forests vanishing
    • fossil fuels causing pollution
      • not enough fossil fuels, small replenishment rate
    • Its everyone's responsibility to care for the environment
  • Modern Commodities
    • heating/cooling
    • transportation
    • manufacturing
  • Energy consumption measured in
    • kilowatt hours
    • coal plant per kilowatt hour generates 1.57 lb of CO2

Notes - Historical Background

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • One of the oldest forms of energy
    • windmills
    • water mills
  • Types of windmills based on rotation axis
    • vertical axis
    • horizontal axis
  • Generation for electricity generation 1970s
    • oil crisis 1972
  • Up until 1992 commercial wind turbines generated roughly 225 kilowatts
    • 2002 generation grown by factor of 10
    • now installations include 6183 MW wind farms
  • EWEA(European Wind Energy Association)
    • 2009 wind farms built total 199 offshore 577 MW
    • Denmark provided 20% of its energy from wind

Notes - Introduction

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • wind turbines are much larger than previously used
  • difficult to control
  • understand rules of nature and behavior

Tuesday, November 27, 2012

Paper - Rational Decision Making

Rational Decision Making:
Large Hadron Collider Scenarios

    The more humans have tried to learn about nature the more they realize how little they understand. Physicist Gary Zukhov once said that, “Physicists have ‘proved,’ rationally, that our rational ideas about the world in which we live are profoundly deficient.” As an addendum we should add that the same applies to our own minds. We have to be able to make fully rational decisions when they have long lasting impacts and consequences.

    Why would do we want to make rational decisions? The reason is that it’s often the most optimal choice. A rational decision is made by listing out the characteristics and consequences of a choice, and choosing the one we think is best. The primary issue here is figuring these characteristics and consequences out in complex large scale systems and decisions. Its easy if the system is small, for example, when grocery shopping, we have can make rational decisions based on the label and our tastes without drastic consequences, making it a good choice. However when the situation is more complex, and there isn’t a label we can check things become more difficult.

    The first obstacle in dealing with rationality is simply the lack of information, or the presence of misinformation. For example, lets take the Large Hadron Collider. There was opposition raised against it by the many doomsday scenarios that it could create. Perhaps most famously the idea that the Large Hadron Collider can create black holes that would destroy the world. Now from a physics perspective, we can realize and calculate that the black holes created will be so small that it will almost immediately evaporate due to Hawking Radiation. This is the process where the spontaneous formation and destruction of particles occur along the edge of a black hole, resulting in one particle/antiparticle exiting the black hole, and one being sucked in, reduces the mass of the black hole causing it to evaporate.

    However, Hawking Radiation as a process isn’t generally known. This is a case of the absence of information in the general public. If everyone readily knew about Hawking radiation it would be clear that this threat is not an issue. Since this isn’t the case, it can cause people to over evaluate the dangers of the Large Hadron Collider leading to an irrational risk/benefit analysis.

    Another issue linked to this scenario are the problems of anchoring and overconfidence. Many people envision a black hole as an infinitely absorbing object that just gets larger and larger at a rapid rate. This has been popularized from various science fiction movies and most people believe that a black hole is a vast absorption machines that sucks in everything around it. In reality, although its impossible to escape a black hole, it doesn’t grow as actively as it is seen in the movies. We know that there are many black holes in the universe so theres no way we could exist if they were as terrible as they are depicted in the movies. For example, if the Sun turned into a black hole, although we would notice the lack of light in 8 minutes, the orbits of the planets wouldn’t change.

    This anchoring occurred because of the way in which the human mind works. Most people's first experience with a black hole is in the form of a movie. Since it was our first experience with this object, it is the most easily recalled and anchored in our memory in that way. This anchoring is due to the availability heuristic. A heuristic is an experience based method towards problem solving. The availability heuristic is when we make a decision based on the easiest event that we can recall. In this case, its much easier to recall the vivid dramatic events in a movie, over something that can be learned in a classroom, or through scholarly articles.

    The lack of information in the general public combined with misinformation caused by the availability heuristic could easily have led government officials to make an irrational decision regarding the Large Hadron Collider to shut it down. Now we actually haven’t done extensive analysis on what the risks/benefits of the LHC are worth but this is already considered an irrational decision because it was motivated by incorrect information.

    This hypothetical situation leads us to another aspect in making rational decisions, recognizing feedback loops. There are powerful information and societal feedback loops inherent to our society. Lets say the media spreads the word for the potential of world destruction due to the Large Hadron Collider. This initial spread of information could affect people in high ranking positions in a socio political group. In this example lets take the theological example of high officials in the church. If these officials change the church’s official stance on the Large Hadron Collider the media will publicize it as one of their sources. This leads to more to more reports being made on the subject, which could reinforce the stance of the church, reinforcing the stance of the media, so on and so forth. This is an example of how even an initially incorrect or false claim can grow itself into a large multi group movement.

    The above scenarios all deal with the lack of information or misinformation and how it can spread to become a threat to rational decision making. The next case deals with how we process information. When we consider a complex project like the Large Hadron Collider, we have to take into account more the risks and benefits than just discovering the Higgs boson and the potential to create black holes. We also have to consider it as an engineering project and make decisions based on a sustainability standpoint.

    We can go through a few calculations here. It took about 4.75 billion dollars to construct the LHC, the electricity costs run about $23.5 million per year, and requires an operating budget of 1 billion dollars. This is a huge economic investment. Depending on the location this could cause huge issues, for example if the LHC was built in a rural 3rd world country so that it’d be physically out of the way from first world countries, it could devastate that locations economy as its resources gets forced into one project. Likewise we also have to consider its yearly costs, taking into account that the average cost for electricity in Europe is about 17 euro cents a kilowatt, we can calculate that the collider uses up about 150 million kilowatts a year. This is enough to power about 12,000 homes. Again this could be a huge burden on the host country for this project depending on how wealthy they originally were.

    In reality, the Large Hadron Collider was built in Switzerland which has good low emission production of electricity, and so the environmental cost in greenhouse gases for the LHC is only about 700,000 kg of CO2. Now, we can weigh this in both an economic and ethical sense. Assuming we view progress as a worthy goal we can think that these costs seem to be fairly reasonable for the possibility for completing the standard model of particle physics which leads to development in every aspect of almost all sciences. On the other hand considering the costs would this money have been better spent towards alternative energy development or medical research towards curing cancer? This are the things we have to consider in order to make the decision fully rational by obtaining the correct information and processing it in all aspects socially, economically, and ethically. So as we can see there are many different obstacles when it comes to making rational decisions. The issues range from spreading correct information to recalling appropriate information, from recognizing trends in a system, to determining what is the correct choice. However, although these topics may seem disparate, we can address them all in the same way, through education. One of the aspects of education is distributing correct information in a way which is easy to recall which addresses the first two obstacles. Recognizing trends and making appropriate choices is comparable to learning appropriate problem solving techniques, which is the other aspect of education. The last aspect of our education is in our values as a person. We have to consider whether or not our decisions are ethical and work towards a social good, which again we grow through not only our official education but simply through experiencing life. When we consider and weigh all these aspects we can then make rational decisions that benefit us all.