info@truenorthpower.com
A Publication of the FREE Wind Press - May be re-printed for personal use only
Copyright (C) 2007 TRUE-NORTH Power Systems
For commercial or non-profit publication contact TRUE-NORTH Power Systems
Lion's Head ON N0H 1W0 - (519) 793-3290
A Publication of the FREE Wind Press - May be re-printed for personal use only
Copyright (C) 2007 TRUE-NORTH Power Systems
For commercial or non-profit publication contact TRUE-NORTH Power Systems
Lion's Head ON N0H 1W0 - (519) 793-3290
Issue 1:2 Headlines: February 2003
- What Happened to Chinook?
- Wind Turbines - The Bird Myth.
- Lakota Turbine, Feature Display in the National Home Show 4-13 April 03.
- Cost of Ontario Energy - Jan-Feb 03
- Why aren't 10 blades better than 2?
- The Noise - Problem or Not?
Chinook Reverts to it's Original Name
TRUE-NORTH Power Systems originally chose the name "Chinook" for introduction of an advanced small wind turbine for the Canadian market. This was because Chinook, meaning "Warm winter wind", was to be a recognizable and distinctly Canadian name for the Lakota product line. Lakota turbine and tower components are manufactured by the AEROMAX Corporation of Prescott Valley Arizona and final assembly is done here in Canada.
Unfortunately, we have become aware that there is a potential for confusion with another Canadian wind turbine from called the "Chinook 2000", a 250kW vertical-axis turbine produced by Sustainable Energy Technologies of Calgary Alberta. To avoid this confusion it was decided, in Feb 2003, to retain the Lakota product name but continue to use the "S" (standard) and "SC" (Severe Climate) designations on the Canadian product line.
The SC models are sealed with a linear polyurethane, titanium-dioxide aircraft coating that is particularly tough and protects the turbine and blades from rain, ice, snow, sand, dust corrosion and ocean salt spray.
Lakota: - The Lakota people belong to the larger group Oceti Sakowin (meaning "the seven places of fire"), called the Sioux by the white man after the Chippewa (Ojibwa) word for their enemies "nadouessioux," meaning "little snakes." Legend tells that long ago at a sacred lake, Sun (Wi), who appears as fire on earth, revealed the tribal organization to the Sioux people. Thus began the tradition of the seven council fires, the Lakota among them.
An important part of Lakota culture focuses on the larger community of their people, as represented by the council fires. For this community of the Great Plains, the buffalo was not only key to Lakota survival, it also held great spiritual significance.
In the tradition of their ancestors, the Lakota family extends beyond the parents and their children: younger generations learn from their elders, who hold the wisdom of the tribe. The Lakota way places an emphasis on home, and spirituality plays a role in every action.
Lakota is one of the three similar languages spoken by the Sioux; the others are Dakota and Nakota. The Lakota are made up of seven bands: Oglala ("dust scatterers"), Sicanju (or Brulé, "burnt thighs"), Hunkpapa ("end of the circle"), Miniconjous ("planters beside the stream"), Sihasapa (or Blackfeet, different from the Blackfeet tribe), Itazipacola (or Sans Arc, "without bows") and Oohenupa ("two kettles").
TRUE-NORTH Power Systems originally chose the name "Chinook" for introduction of an advanced small wind turbine for the Canadian market. This was because Chinook, meaning "Warm winter wind", was to be a recognizable and distinctly Canadian name for the Lakota product line. Lakota turbine and tower components are manufactured by the AEROMAX Corporation of Prescott Valley Arizona and final assembly is done here in Canada.
Unfortunately, we have become aware that there is a potential for confusion with another Canadian wind turbine from called the "Chinook 2000", a 250kW vertical-axis turbine produced by Sustainable Energy Technologies of Calgary Alberta. To avoid this confusion it was decided, in Feb 2003, to retain the Lakota product name but continue to use the "S" (standard) and "SC" (Severe Climate) designations on the Canadian product line.
The SC models are sealed with a linear polyurethane, titanium-dioxide aircraft coating that is particularly tough and protects the turbine and blades from rain, ice, snow, sand, dust corrosion and ocean salt spray.
Lakota: - The Lakota people belong to the larger group Oceti Sakowin (meaning "the seven places of fire"), called the Sioux by the white man after the Chippewa (Ojibwa) word for their enemies "nadouessioux," meaning "little snakes." Legend tells that long ago at a sacred lake, Sun (Wi), who appears as fire on earth, revealed the tribal organization to the Sioux people. Thus began the tradition of the seven council fires, the Lakota among them.
An important part of Lakota culture focuses on the larger community of their people, as represented by the council fires. For this community of the Great Plains, the buffalo was not only key to Lakota survival, it also held great spiritual significance.
In the tradition of their ancestors, the Lakota family extends beyond the parents and their children: younger generations learn from their elders, who hold the wisdom of the tribe. The Lakota way places an emphasis on home, and spirituality plays a role in every action.
Lakota is one of the three similar languages spoken by the Sioux; the others are Dakota and Nakota. The Lakota are made up of seven bands: Oglala ("dust scatterers"), Sicanju (or Brulé, "burnt thighs"), Hunkpapa ("end of the circle"), Miniconjous ("planters beside the stream"), Sihasapa (or Blackfeet, different from the Blackfeet tribe), Itazipacola (or Sans Arc, "without bows") and Oohenupa ("two kettles").
Wind Turbines - The Bird Myth.
It's common knowledge that wind turbines kill birds, right? That's true, but often common knowledge is wrong or at best misleading. Years of experience with wind turbines has shown that birds have been known to fly into the path of the blades and be killed or injured especially at night or in bad weather. The same is true for cars. In fact a lot more birds are killed every day by cars and cats than turbines, but even that's not the whole story.
This is from ROCKWOOD, Ontario, CA, 2003-01-29, Read the whole story at [Refocus Weekly]
An average wind turbine kills less than two birds per year, it notes, "similar to a car and less than many housecats," but the document says that a turbine's reduction on bird mortality must be considered in addition to the issue over direct bird deaths due to interaction with turbines.
At least 200 million birds reside in or pass through Ontario every year. "Since birds spend all of their time outdoors, and since their metabolism rate is higher than human metabolism, it is reasonable to assume that the impact on birds is similar or greater than the impact on humans," it argues. If death rates of birds are similar to humans, more than 34,200 bird die each year from NOx emissions and, since 15% of NOx emissions come from power generation, 5,130 bird deaths each year could be avoided by replacing coal-fired power plants with wind turbines.
It's common knowledge that wind turbines kill birds, right? That's true, but often common knowledge is wrong or at best misleading. Years of experience with wind turbines has shown that birds have been known to fly into the path of the blades and be killed or injured especially at night or in bad weather. The same is true for cars. In fact a lot more birds are killed every day by cars and cats than turbines, but even that's not the whole story.
This is from ROCKWOOD, Ontario, CA, 2003-01-29, Read the whole story at [Refocus Weekly]
An average wind turbine kills less than two birds per year, it notes, "similar to a car and less than many housecats," but the document says that a turbine's reduction on bird mortality must be considered in addition to the issue over direct bird deaths due to interaction with turbines.
At least 200 million birds reside in or pass through Ontario every year. "Since birds spend all of their time outdoors, and since their metabolism rate is higher than human metabolism, it is reasonable to assume that the impact on birds is similar or greater than the impact on humans," it argues. If death rates of birds are similar to humans, more than 34,200 bird die each year from NOx emissions and, since 15% of NOx emissions come from power generation, 5,130 bird deaths each year could be avoided by replacing coal-fired power plants with wind turbines.
Lakota To Be Seen on the Featured Environmental Home Display
National Home Show 4-13 April 03
Toronto - Exhibition Place
TRUE-NORTH Power Systems and the Lakota SC wind turbine will be part of the Featured display called Home Alive! The House that Thinks, Drinks and Breathes will be fully constructed as a Feature Model at the 2003 National Home Show in Toronto, from April 4th to 13th, 2003. Read all about Home Alive!
This is a first for sustainable home ideas. Over 300,000 visitors over 10 days will have the opportunity to learn about the many unique Home Alive! features. This innovative modular straw bale home will be fully constructed inside the conference centre at the CNE grounds in Toronto and contain hundreds of environmental and energy saving products and building techniques.
After the National Home Show, Home Alive! will be disassembled, then rebuilt at the non-profit Everdale Environmental Learning Centre, one hour north-west of Toronto. By fall of 2003, Home Alive! will accept its first live-in tenants and re-open its doors for monthly tours and real-time internet virtual tours, providing the public with on-going opportunities to learn about the most current and appropriate living ideas in Canada.
Designed and built by Ben Polley of Harvest Homes together with landscape architecture by Brad Peterson. The Home Alive! project will incorporate numerous planet-friendly building, product and living systems ideas. One of the few places you'll be able to see these ideas, all in one place and working together.
Come see the new Lakota SC turbine . . up close.
[missing image]
National Home Show 4-13 April 03
Toronto - Exhibition Place
TRUE-NORTH Power Systems and the Lakota SC wind turbine will be part of the Featured display called Home Alive! The House that Thinks, Drinks and Breathes will be fully constructed as a Feature Model at the 2003 National Home Show in Toronto, from April 4th to 13th, 2003. Read all about Home Alive!
This is a first for sustainable home ideas. Over 300,000 visitors over 10 days will have the opportunity to learn about the many unique Home Alive! features. This innovative modular straw bale home will be fully constructed inside the conference centre at the CNE grounds in Toronto and contain hundreds of environmental and energy saving products and building techniques.
After the National Home Show, Home Alive! will be disassembled, then rebuilt at the non-profit Everdale Environmental Learning Centre, one hour north-west of Toronto. By fall of 2003, Home Alive! will accept its first live-in tenants and re-open its doors for monthly tours and real-time internet virtual tours, providing the public with on-going opportunities to learn about the most current and appropriate living ideas in Canada.
Designed and built by Ben Polley of Harvest Homes together with landscape architecture by Brad Peterson. The Home Alive! project will incorporate numerous planet-friendly building, product and living systems ideas. One of the few places you'll be able to see these ideas, all in one place and working together.
Come see the new Lakota SC turbine . . up close.
[missing image]
Why aren't 10 blades better than 2?
A common thought that many people have wondered about . . .
Why do modern wind turbines use only 2 or 3 narrow blades? To a logical way of thinking, similar to a sailing ship, wouldn't a larger surface area harness more energy? Wouldn't a wind turbine with many blades covering a large surface area produce higher torque and have more power? Combined with the right gears, that would get the generator's rpm up and allow it to run a very high speed output? Those narrow "spindly" blades seem to be missing 70% of the available wind.
A windmill or wind generator captures its energy by deflecting the wind through the blades. If you think about it though, a solid disk would not capture any energy because the wind would just have to go around it. But, you've probably seen many farm windmills with multiple blades doing just great. This actually points out the difference between "Windmills" and "Wind Turbines". Multi-bladed farm windmills are usually used for pumping water in low speed wind because the mulitple blades provide higher torque at low wind speed. Wind Turbines, on the other hand, are designed to produce electricity but they work better when they turn at high speed. They get that high speed thrust at higher wind speeds, where the energy density is higher; ie. there is more energy per square foot than at low speed. In fact the energy of the wind varies with the cube of the wind speed. If the wind speed is twice as high, say 20 mph vs 10 mph, then it contains 2 x 2 x 2 = 8, or eight times as much energy.
Actually the most aerodynamically efficient blade configuration, believe it or not is 1 . . yes ONE Blade . . . with a counter weight, but unfortunately it has many other balance and fatigue drawbacks, and although aerodynamically very efficient, the design is not well suited for high wind conditions either. A two bladed system works well if aerodynamically designed properly but there is a "see-saw" pivot problem that develops counter-productive gyroscopic forces and puts more fatigue forces on the blades and hub. Three blades is a good compromise for all of the above problems and for a number of other aerodynamic reasons. More than three blades and you get into more expensive, heavier and more complex hub design as well as speed control issues.
Multi-blade discs do capture more wind and have better torque at the low wind speed . . very good for pumping water, but . . . the energy available from low speed wind is also much lower than what can be extracted from wind just a few mph faster. Remember it's 8 times more energy from doubling the speed. So to design for 15-30mph and especially the 30mph wind regime, you need fewer blades to extract the most energy and still keep the systems light and uncomplicated mechanically.
Turns out three is a very good compromise for medium to high wind and that's where the energy is. Betz' law says that "You can only convert a theoretical maximum of 16/27ths (or 59%) of the kinetic energy in the wind to mechanical energy using a wind turbine". That's 59% of the energy in a horizontal column of air passing through the rotor disk. And that's the THEORETICAL Max. Most small wind turbines are doing well if they achieve 22-25%. Betz' law was first formulated by the German Physicist Albert Betz in 1919.
If you want to learn about the power density of the wind go to the Danish energy site and read up on Weibull Distribution and Betz Law at windpower.com.
A common thought that many people have wondered about . . .
Why do modern wind turbines use only 2 or 3 narrow blades? To a logical way of thinking, similar to a sailing ship, wouldn't a larger surface area harness more energy? Wouldn't a wind turbine with many blades covering a large surface area produce higher torque and have more power? Combined with the right gears, that would get the generator's rpm up and allow it to run a very high speed output? Those narrow "spindly" blades seem to be missing 70% of the available wind.
A windmill or wind generator captures its energy by deflecting the wind through the blades. If you think about it though, a solid disk would not capture any energy because the wind would just have to go around it. But, you've probably seen many farm windmills with multiple blades doing just great. This actually points out the difference between "Windmills" and "Wind Turbines". Multi-bladed farm windmills are usually used for pumping water in low speed wind because the mulitple blades provide higher torque at low wind speed. Wind Turbines, on the other hand, are designed to produce electricity but they work better when they turn at high speed. They get that high speed thrust at higher wind speeds, where the energy density is higher; ie. there is more energy per square foot than at low speed. In fact the energy of the wind varies with the cube of the wind speed. If the wind speed is twice as high, say 20 mph vs 10 mph, then it contains 2 x 2 x 2 = 8, or eight times as much energy.
Actually the most aerodynamically efficient blade configuration, believe it or not is 1 . . yes ONE Blade . . . with a counter weight, but unfortunately it has many other balance and fatigue drawbacks, and although aerodynamically very efficient, the design is not well suited for high wind conditions either. A two bladed system works well if aerodynamically designed properly but there is a "see-saw" pivot problem that develops counter-productive gyroscopic forces and puts more fatigue forces on the blades and hub. Three blades is a good compromise for all of the above problems and for a number of other aerodynamic reasons. More than three blades and you get into more expensive, heavier and more complex hub design as well as speed control issues.
Multi-blade discs do capture more wind and have better torque at the low wind speed . . very good for pumping water, but . . . the energy available from low speed wind is also much lower than what can be extracted from wind just a few mph faster. Remember it's 8 times more energy from doubling the speed. So to design for 15-30mph and especially the 30mph wind regime, you need fewer blades to extract the most energy and still keep the systems light and uncomplicated mechanically.
Turns out three is a very good compromise for medium to high wind and that's where the energy is. Betz' law says that "You can only convert a theoretical maximum of 16/27ths (or 59%) of the kinetic energy in the wind to mechanical energy using a wind turbine". That's 59% of the energy in a horizontal column of air passing through the rotor disk. And that's the THEORETICAL Max. Most small wind turbines are doing well if they achieve 22-25%. Betz' law was first formulated by the German Physicist Albert Betz in 1919.
If you want to learn about the power density of the wind go to the Danish energy site and read up on Weibull Distribution and Betz Law at windpower.com.
The Real Cost of Ontario Energy - Jan-Feb 03
AS I write this, 22 Feb 03 the cost of energy in Ontario is:
Current Market Demand: 19,600 MW Current Hourly Price (HOEP): $152.19 /MWh (15.22¢/kWh) at 11:00 a.m. EST February 22
Average Price Since May 1: $54.47 /MWh (5.45¢/kWh)
Hourly Uplift Charge Estimate: $4/MWh (0.4¢/kWh) at 11:00 a.m.
The chart below is published along with all other Ontario real-time and historical data by the IMO (Independent Electricity Marketing Operator)of Ontario. They operate like an electrical energy "Stock Exchange" and buy and sell energy as supply and demand fluctuates.
They calculate it in "Cents/Megawatt" but 0.60 cents/ megawatt = 0.06 cents/Kilowatt so you can see from the chart the median price level is about 6 cents. Don't forget, this is just the SPOT price. The REAL cost is the number that comes from dividing your KwHrs used by the total amount you paid. That's the number that really counts, regardless of any "price freeze".
[missing image]
AS I write this, 22 Feb 03 the cost of energy in Ontario is:
Current Market Demand: 19,600 MW Current Hourly Price (HOEP): $152.19 /MWh (15.22¢/kWh) at 11:00 a.m. EST February 22
Average Price Since May 1: $54.47 /MWh (5.45¢/kWh)
Hourly Uplift Charge Estimate: $4/MWh (0.4¢/kWh) at 11:00 a.m.
The chart below is published along with all other Ontario real-time and historical data by the IMO (Independent Electricity Marketing Operator)of Ontario. They operate like an electrical energy "Stock Exchange" and buy and sell energy as supply and demand fluctuates.
They calculate it in "Cents/Megawatt" but 0.60 cents/ megawatt = 0.06 cents/Kilowatt so you can see from the chart the median price level is about 6 cents. Don't forget, this is just the SPOT price. The REAL cost is the number that comes from dividing your KwHrs used by the total amount you paid. That's the number that really counts, regardless of any "price freeze".
[missing image]
The Noise - Problem or Not?
A lot has been done to study the noise associated with wind turbines, largely because the original designs were not very aerodynamically or mechanically well designed. Constant chord blades made of wood, metal or plastic tend to flex and flutter under high wind load. Some systems are designed to flex so they will shed the load and not overspeed in high winds. Larger turbines, particularly those that use heavy gear boxes or aerodynamic braking mechanisms tend to make more noise than those designed for stiffness and more controlled speed of rotation under load.
Ideally, Wind Turbine Generators (WTGs) should have stiffer blades to capture as much energy as possible from a given column of air. This stiffness leads to low blade flutter and a lower noise signature. A modern small wind turbine should make virtually no noise under normal conditions. Under high wind conditions, above 30mph, the ambient wind noise should be louder than the blade or generator noise. In the 80s and 90s some of the small turbines gained the reputation of 'Buzzing' loudly when they performed under high winds and this lead to numberous neighbourhood lawsuits in the US from people being kept awake at night by their environmentally conscious neighbours.
Fortunately, most manufacturer have corrected this problem by modifying their controllers or changing the blade designs of their turbines. Unfortunately, these modified designs tend to limit output or "hide" from the wind when it is strong, just when they should be producing peak power. Even though some of the new designs have totally eliminated this problem through proper blade design, the urban myth has persisted that wind turbines are noisy and ALL WTGs are the same.
Go and visit a small wind turbine while it's running in 15-20mph wind and you should only hear a slight swishing sound if you are directly underneath it. . . . and that's if you listen carefully. You might be able to hear the generator if you put your ear to the tower. (By the way, don't do that in a thunder storm.)
If you hear more than that, it's probably an older design blade or controller mechanism at work.
A lot has been done to study the noise associated with wind turbines, largely because the original designs were not very aerodynamically or mechanically well designed. Constant chord blades made of wood, metal or plastic tend to flex and flutter under high wind load. Some systems are designed to flex so they will shed the load and not overspeed in high winds. Larger turbines, particularly those that use heavy gear boxes or aerodynamic braking mechanisms tend to make more noise than those designed for stiffness and more controlled speed of rotation under load.
Ideally, Wind Turbine Generators (WTGs) should have stiffer blades to capture as much energy as possible from a given column of air. This stiffness leads to low blade flutter and a lower noise signature. A modern small wind turbine should make virtually no noise under normal conditions. Under high wind conditions, above 30mph, the ambient wind noise should be louder than the blade or generator noise. In the 80s and 90s some of the small turbines gained the reputation of 'Buzzing' loudly when they performed under high winds and this lead to numberous neighbourhood lawsuits in the US from people being kept awake at night by their environmentally conscious neighbours.
Fortunately, most manufacturer have corrected this problem by modifying their controllers or changing the blade designs of their turbines. Unfortunately, these modified designs tend to limit output or "hide" from the wind when it is strong, just when they should be producing peak power. Even though some of the new designs have totally eliminated this problem through proper blade design, the urban myth has persisted that wind turbines are noisy and ALL WTGs are the same.
Go and visit a small wind turbine while it's running in 15-20mph wind and you should only hear a slight swishing sound if you are directly underneath it. . . . and that's if you listen carefully. You might be able to hear the generator if you put your ear to the tower. (By the way, don't do that in a thunder storm.)
If you hear more than that, it's probably an older design blade or controller mechanism at work.