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 4:2 Headlines: February 2006
Will a Small Turbine Run my House?
Many people who are learning about renewable energy wonder if they can use a small wind turbine or some solar panels to replace the utility power. This is a common goal because utility power is getting more and more expensive and sometimes unreliable . . . more importantly we all want more control over the price and availability of the power we use. I use only 400-450kW hours each month in an energy efficient home with new electrical appliance fridge, stove, washer, dryer, dishwasher etc. The cost shown on my bill is about $20 (at 5 Cents/kWhr) and yet my whole Utility bill is over $65 . . . so the real cost is more like 14.4 cents per kW and the note in my bill this month said they've applied to raise the delivery price another 6% starting in May 06. It seems logical to anyone, that if there is freely available power in the wind and sun on my property every day, why not use that instead of expensive and rising utility power.
Quite simply the answer is YES and NO . . . the qualifier is "your house". Since every house is different every family's energy demands are different the answer is "it depends". Yes a 1-2kw small wind turbine with maybe a few hundred watts of solar will do the trick, if you own a very energy efficient home and appliances like most Europeans have. . . and most importantly you do not heat your home or your hot water with electricity. To do that you need a 7-10kW machine that is grid-tied . . and now you're talking $35-$50,000 Cdn just for the turbine installation. Most Europeans use 300-400kWhrs per month on average. But the answer is NO if you have a 3500 square foot Canadian home with a hot tub and electric base board heaters. Bear with me for a paragraph of technical stuff and you'll begin to see the essence of the small turbine sizing in a new light.
One of the most inefficient things you can do is turn electrons directly into heat and so any appliance that does that, like a water heater or stove or dryer is going to take a lot of electricity. Well, you would think then that all you need is a larger turbine . . yes? . . . YES that's true with a big enough turbine you can do it all . . but how big? Wind and solar are both "low density" energies. That means you need a large collector to capture a large amount of energy. There is a simple formula for calculating the wind power available in Watts.
It's P (watts) = 1/2 X Air Density X Area X Velocity (cubed) X the efficiency of the system (Cpe).
If you produce say 1000 watts continuously for a full hour then you have produced one kilowatt hour of Energy. Power is work in Watts. Energy is work done over a period of time (1 hour) Kilowatt hours. The density of the air is a minor variant so a number like 1.2 would be pretty close most of the time. Area is the cross sectional area of the turbine blades (the collector and the only thing you can control). What REALLY MATTERS is the density of the power available in the wind . . . that's what mass of air is passing through our turbine blades each hour. Think of it as a continuous column of air that we can weigh some section of . . (an "hours worth" of air for example). The bigger the mass in an hour the more energy we can extract from it in an hour. That mass can be slowed and therefore it can "give up energy" to the blades that are changing the direction of that mass of air particles by creating lift using an airfoil. As we redirect or change the direction slightly we transfer kinetic energy in the wind into lift and rotational energy in the turbine. But a German fellow named Betz back in the 1800s figured out that you can only extract 16/27ths (~59%) of that energy before the wind sees your turbine as a solid obstacle and simply goes around it. So about 59% is the most you can extract even if your turbine is 100% efficient.
Most small wind turbine systems have an overall efficiency of about 25%. some achieve 30-35%. . . so to start with, you can expect to get only 30% of 59% of the total energy available. If there was 1kW of power in the size column of air your turbine is collecting from then you can only expect to actually collect 177 watts (30% of 59% of 1000w). There are only so many "watts per square meter" cross section of wind. Let's say you have need 5 kw of power and the energy density is only 55 watts per square meter (12mph) then you need a turbine with almost 9 meter blades (that's over 18 meters across 250SqM cross section . . HUGE!) and it needs to be operating at near 45% efficiency.
What really increases the power available dramatically is the speed (velocity) of the wind. That's a cubed function . . meaning each time the wind speed increases only 2-3 mph you have double the power available to capture. What you get at 20mph (32.2km/hr) is 8 times more than you have available at 10mph (16km/hr) . . That cube function is 2 X 2 X 2 or 8 times the power.... so you can actually get 5kw from a turbine with 1 meter blades (2 meters across) and about 3.5 sq Meter cross section . . but . . the velocity of the wind has to be over 45mph (~75km/hr). The wind at 45mph has a power density of nearly 2800watts per square meter. Can you imagine what it is during a hurricane like Katrina packing winds of over 120mph . . well I'll tell you . . it's over 50,000 watts per square meter. Let's look at a typical personal wind system cross section of 3.5 Sq Meter and see how the energy equation works.
Many people who are learning about renewable energy wonder if they can use a small wind turbine or some solar panels to replace the utility power. This is a common goal because utility power is getting more and more expensive and sometimes unreliable . . . more importantly we all want more control over the price and availability of the power we use. I use only 400-450kW hours each month in an energy efficient home with new electrical appliance fridge, stove, washer, dryer, dishwasher etc. The cost shown on my bill is about $20 (at 5 Cents/kWhr) and yet my whole Utility bill is over $65 . . . so the real cost is more like 14.4 cents per kW and the note in my bill this month said they've applied to raise the delivery price another 6% starting in May 06. It seems logical to anyone, that if there is freely available power in the wind and sun on my property every day, why not use that instead of expensive and rising utility power.
Quite simply the answer is YES and NO . . . the qualifier is "your house". Since every house is different every family's energy demands are different the answer is "it depends". Yes a 1-2kw small wind turbine with maybe a few hundred watts of solar will do the trick, if you own a very energy efficient home and appliances like most Europeans have. . . and most importantly you do not heat your home or your hot water with electricity. To do that you need a 7-10kW machine that is grid-tied . . and now you're talking $35-$50,000 Cdn just for the turbine installation. Most Europeans use 300-400kWhrs per month on average. But the answer is NO if you have a 3500 square foot Canadian home with a hot tub and electric base board heaters. Bear with me for a paragraph of technical stuff and you'll begin to see the essence of the small turbine sizing in a new light.
One of the most inefficient things you can do is turn electrons directly into heat and so any appliance that does that, like a water heater or stove or dryer is going to take a lot of electricity. Well, you would think then that all you need is a larger turbine . . yes? . . . YES that's true with a big enough turbine you can do it all . . but how big? Wind and solar are both "low density" energies. That means you need a large collector to capture a large amount of energy. There is a simple formula for calculating the wind power available in Watts.
It's P (watts) = 1/2 X Air Density X Area X Velocity (cubed) X the efficiency of the system (Cpe).
If you produce say 1000 watts continuously for a full hour then you have produced one kilowatt hour of Energy. Power is work in Watts. Energy is work done over a period of time (1 hour) Kilowatt hours. The density of the air is a minor variant so a number like 1.2 would be pretty close most of the time. Area is the cross sectional area of the turbine blades (the collector and the only thing you can control). What REALLY MATTERS is the density of the power available in the wind . . . that's what mass of air is passing through our turbine blades each hour. Think of it as a continuous column of air that we can weigh some section of . . (an "hours worth" of air for example). The bigger the mass in an hour the more energy we can extract from it in an hour. That mass can be slowed and therefore it can "give up energy" to the blades that are changing the direction of that mass of air particles by creating lift using an airfoil. As we redirect or change the direction slightly we transfer kinetic energy in the wind into lift and rotational energy in the turbine. But a German fellow named Betz back in the 1800s figured out that you can only extract 16/27ths (~59%) of that energy before the wind sees your turbine as a solid obstacle and simply goes around it. So about 59% is the most you can extract even if your turbine is 100% efficient.
Most small wind turbine systems have an overall efficiency of about 25%. some achieve 30-35%. . . so to start with, you can expect to get only 30% of 59% of the total energy available. If there was 1kW of power in the size column of air your turbine is collecting from then you can only expect to actually collect 177 watts (30% of 59% of 1000w). There are only so many "watts per square meter" cross section of wind. Let's say you have need 5 kw of power and the energy density is only 55 watts per square meter (12mph) then you need a turbine with almost 9 meter blades (that's over 18 meters across 250SqM cross section . . HUGE!) and it needs to be operating at near 45% efficiency.
What really increases the power available dramatically is the speed (velocity) of the wind. That's a cubed function . . meaning each time the wind speed increases only 2-3 mph you have double the power available to capture. What you get at 20mph (32.2km/hr) is 8 times more than you have available at 10mph (16km/hr) . . That cube function is 2 X 2 X 2 or 8 times the power.... so you can actually get 5kw from a turbine with 1 meter blades (2 meters across) and about 3.5 sq Meter cross section . . but . . the velocity of the wind has to be over 45mph (~75km/hr). The wind at 45mph has a power density of nearly 2800watts per square meter. Can you imagine what it is during a hurricane like Katrina packing winds of over 120mph . . well I'll tell you . . it's over 50,000 watts per square meter. Let's look at a typical personal wind system cross section of 3.5 Sq Meter and see how the energy equation works.
The upper purple part is the energy that is missed or "uncapturable" as a certain wind speed. The blue part of the column represents the potential power that can be captured by a VERY efficient machine (roughly 40% efficient) and the two stacked columns together represent the total energy in a 3.5 sq Meter cross-section of wind. Look at the first column (10mph) there is no energy there . . barely 32watts per sq meter and you can only expect to capture 30-35% of that if your 2 meter cross section system is 35% efficient overall. So don't get overly concerned about "low start-up" speeds that manufacturers quote. At a 6mph startup there is only 7 watts per square meter and the output of your small turbine can't be more than 9-10 watts total. If it's not blowing at least 10mph there's nothing there to capture unless you have a REALLY big turbine. .
So to achieve any particular power . . low wind speed - low power density - BIG turbine needed . . . . High speed wind - high power density - smaller turbine needed. Trouble is the wind velocity is changing all the time. One minute it's calm . . next day it's blowing like heck and you need a turbine that is not too big to get blown away, but big enough to capture some useful amount energy. That is, it needs to be as efficient as possible. Most of the time the wind may only be 10-12mph. If this is your "average" wind then it's only producing 10-20 watts per square meter cross section so most people would think it's hardly worth trying. Well since we've noticed the velocity is a cube function we can expect nearly twice the energy if the wind only goes to 15mph (24km/hr) we can expect 40-50watts/sqM and if we have a turbine with 3.5 SqM cross section then we can capture about 180W/hr of power. Just going to 19mph that increases to about 360W and whenever there's a good wind like 25-30mph (40-50km.hr) we can expect to get 800-1400 watts from your turbine with 1 meter blades. At 30 mph there is over 850 w/SqM power density and if I only get an hour of good wind like that it's as if I collected energy for over 16hrs at 10mph (16km/hr).
So a small wind turbine can produce a lot when the power density is high . . and that is only indirectly related to your "Average" wind speed. What matters is how often does the wind get above 15-20mph and how big and how efficient is my turbine. In general I'd say the average Canadian home could benefit from a horizontal axis turbine (HAWT) between 3-12 square meter cross section if it's at least 30% efficient including blades, turbine and drive system. More on horizontal vs. vertical in the article on Vertical Axis Wind Turbines (VAWT) in the next FREE Wind News.
So to achieve any particular power . . low wind speed - low power density - BIG turbine needed . . . . High speed wind - high power density - smaller turbine needed. Trouble is the wind velocity is changing all the time. One minute it's calm . . next day it's blowing like heck and you need a turbine that is not too big to get blown away, but big enough to capture some useful amount energy. That is, it needs to be as efficient as possible. Most of the time the wind may only be 10-12mph. If this is your "average" wind then it's only producing 10-20 watts per square meter cross section so most people would think it's hardly worth trying. Well since we've noticed the velocity is a cube function we can expect nearly twice the energy if the wind only goes to 15mph (24km/hr) we can expect 40-50watts/sqM and if we have a turbine with 3.5 SqM cross section then we can capture about 180W/hr of power. Just going to 19mph that increases to about 360W and whenever there's a good wind like 25-30mph (40-50km.hr) we can expect to get 800-1400 watts from your turbine with 1 meter blades. At 30 mph there is over 850 w/SqM power density and if I only get an hour of good wind like that it's as if I collected energy for over 16hrs at 10mph (16km/hr).
So a small wind turbine can produce a lot when the power density is high . . and that is only indirectly related to your "Average" wind speed. What matters is how often does the wind get above 15-20mph and how big and how efficient is my turbine. In general I'd say the average Canadian home could benefit from a horizontal axis turbine (HAWT) between 3-12 square meter cross section if it's at least 30% efficient including blades, turbine and drive system. More on horizontal vs. vertical in the article on Vertical Axis Wind Turbines (VAWT) in the next FREE Wind News.
AEROMAG Factory Tour
Qingdao Aeromag Wind Energy Equipment Company Limited is a US-China Joint Venture started in Qingdao China (pronounced Ching Dow) back in 2001 after it became obvious that Arizona State and the people who stole their Test Vehicle did not want them building turbines in Arizona. The gated factory has a about 18,000 square feet of warehouse and assembly floor space as well as Guard House, living quarters, kitchen, and offices for the 2-3 dozen employees and staff, some of whom live full time on the premises. Qingdao is located on the north east coast about an hour flight north of Shanghai and maybe 3-4 hr drive south east of Beijing. If you 'd like to see a close up satellite image click the square below.
Qingdao Aeromag Wind Energy Equipment Company Limited is a US-China Joint Venture started in Qingdao China (pronounced Ching Dow) back in 2001 after it became obvious that Arizona State and the people who stole their Test Vehicle did not want them building turbines in Arizona. The gated factory has a about 18,000 square feet of warehouse and assembly floor space as well as Guard House, living quarters, kitchen, and offices for the 2-3 dozen employees and staff, some of whom live full time on the premises. Qingdao is located on the north east coast about an hour flight north of Shanghai and maybe 3-4 hr drive south east of Beijing. If you 'd like to see a close up satellite image click the square below.
Many of these photos were taken by me on my last visit in Jan 06 and the LAKOTA 2006 shots are all more recent. You may note a trailer with a LAKOTA and solar PV on it. That's a demo/promotional/training setup much like the P-Cubed trailer that TRUE-NORTH is building for training and promotion in Canada this year. It's got sponsorship logos from several suppliers like Outback, M+H Power systems (the Australian LAKOTA Dealer from Melbourne). The main sponsor is and Australian power company "Select Power" as you can see on the truck .. but not the Canadian Select Power from Guelph. Its a great shot with a bunch of utility power guys having a look at renewable energy in front of their huge and inefficient . . looks like thermal power plant.
You'll notice the 2006 LAKOTA has an redesigned spring system with and "aft assist" spring that helps cushion the gusts and tends to push it back into wind gently in order to regain power more efficiently. Also the previous newsletter shows the dual brush system that will significantly reduce brush wear and increase power production without increasing the heat load on the brushes.
Lots of pictures of the OB1 parts already on the shelf. If you are like most people you're still wondering if it's for real and you can see from these shots there's a lot of effort gone into it and lots of parts ready to go. The full production line is taking time to get running and begin producing in quantities needed for world-wide distribution, but I expect the FREE Wind Test Centre will begin testing OB1 flight compinents in a few weeks. We have already been testing the OB1 Commander since last November. You can't hand make these sophisticated electronics and use advanced aerospace grade tooling and keep the price down (that's pretty obvious by the price of other machines rated in the 2-3w range).
You'll notice the 2006 LAKOTA has an redesigned spring system with and "aft assist" spring that helps cushion the gusts and tends to push it back into wind gently in order to regain power more efficiently. Also the previous newsletter shows the dual brush system that will significantly reduce brush wear and increase power production without increasing the heat load on the brushes.
Lots of pictures of the OB1 parts already on the shelf. If you are like most people you're still wondering if it's for real and you can see from these shots there's a lot of effort gone into it and lots of parts ready to go. The full production line is taking time to get running and begin producing in quantities needed for world-wide distribution, but I expect the FREE Wind Test Centre will begin testing OB1 flight compinents in a few weeks. We have already been testing the OB1 Commander since last November. You can't hand make these sophisticated electronics and use advanced aerospace grade tooling and keep the price down (that's pretty obvious by the price of other machines rated in the 2-3w range).
PIRATED LAKOTA
Funny how you just kinda know a good design when they see it . . . this picture was taken on a building not too far south of the factory near JiaoZhou China. It's pretty obvious they are LAKOTA blades and Nose Cone. A closer look suggests it uses identical yaw axis parts and probably the brushes and brush holder too. I dare say the windings and magnet rotor at identical. The body is different and the tail is too but the tail boom and tail attachment is clearly LAKOTA. There is no furling system, which is odd, but whoever is copying this turbine does not know why the LAKOTA was built the way it was. First of all there is too much weight forward and that small tail cannot balance that forward weight.
Many parts including blades and other parts have gone missing from the factory warehouse last year when the production manager and a couple of his relatives were planning their own wind turbine company even though they had all signed a non-disclosure non-compete agreement before coming to work at Qingdao Aeromag. They were fired last March for obvious failures to perform and there is evidence they outright tried to destroy Qingdao Aeromag in order to steal the technology. I know because I provided photographic evidence and documentation that clearly shows they were either maliciously trying to damage the company by substituting substandard parts and making unauthorized design changes . . .or at best . . they were incompetent at their jobs. Their new company was discovered recently and these turbine photos only serve to confirm the facts. Legal proceedings have commenced in China.
If you see other blade or turbine designs out there that look strangely like LAKOTA or the OB1 please email me at david@truenorthpower.com and we'll investigate and expose them too.
Funny how you just kinda know a good design when they see it . . . this picture was taken on a building not too far south of the factory near JiaoZhou China. It's pretty obvious they are LAKOTA blades and Nose Cone. A closer look suggests it uses identical yaw axis parts and probably the brushes and brush holder too. I dare say the windings and magnet rotor at identical. The body is different and the tail is too but the tail boom and tail attachment is clearly LAKOTA. There is no furling system, which is odd, but whoever is copying this turbine does not know why the LAKOTA was built the way it was. First of all there is too much weight forward and that small tail cannot balance that forward weight.
Many parts including blades and other parts have gone missing from the factory warehouse last year when the production manager and a couple of his relatives were planning their own wind turbine company even though they had all signed a non-disclosure non-compete agreement before coming to work at Qingdao Aeromag. They were fired last March for obvious failures to perform and there is evidence they outright tried to destroy Qingdao Aeromag in order to steal the technology. I know because I provided photographic evidence and documentation that clearly shows they were either maliciously trying to damage the company by substituting substandard parts and making unauthorized design changes . . .or at best . . they were incompetent at their jobs. Their new company was discovered recently and these turbine photos only serve to confirm the facts. Legal proceedings have commenced in China.
If you see other blade or turbine designs out there that look strangely like LAKOTA or the OB1 please email me at david@truenorthpower.com and we'll investigate and expose them too.
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This brings to mind another group of pirates who wanted to steal LAKOTA and OB1 technology back in 2001 when Aeromag's original "Accelerated Mission Test Vehicle" or AMTV went missing (ie stolen) in Arizona. In the middle of the night, some one wanted that technology really badly because nothing was found of the missing vehicle and LAKOTA for years. In fact, it was only a last summer when hikers came across the stripped out test truck and an abandon canyon not too far from Aeromax original home in Prescott Valley AZ. You can see from the photos that they didn't leave much behind. Fortunately, the vehicle was not carrying the critical microchips and computer firmware from the OB1 and only a LAKOTA turbine was mounted so the key trade secrets were protected. That's the original AMTV with the OB1 under test in the top right photo. It's amazing what people will do to avoid doing their own research.
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Municipal By-laws for Small Wind
I did a presentation at CanWEA last year on Municipal and personal Planning for Small Wind and since then have had a number of municipal and private inquiries about what's good or practical about regulating private small wind installations in Ontario. I dare say many of these ideas apply equally but not completely in other jurisdictions. First of all, the definition of small wind is an issue. The category is simply too broad to apply across the board. For example in the Municipality of Northern Bruce where we are has somewhat arbitrarily defined “COMMERCIAL WIND ENERGY TURBINE” as meaning a structure designed to convert wind to useable energy for the purpose of inclusion into the electrical grid system. Right away that tells me they aren't aware of how personal wind systems can be "grid- tied" and capable of sending power into the grid yet they are not "Commercial" in any way. . . here are some additional considerations.
There is no reason to limit the lot size due to noise of towers. Many private homes have very large antenna towers for ham radio that may interfere with some radio signals but are allowed in most municipalities. As for noise, many small turbines are quite capable of producing good quiet power even when attached to the house. I never recommend that but it is quite often feasible. My experience, at least with stiff bladed turbines, is that in a quiet country setting the leaves in the trees make more noise that the turbine. Impossible to hear when there is any urban traffic. My 45ft tower and 3.5sq meter turbine is literally 2 feet from the corner of my house and yet I never hear it . . inside or outside the house. If you are downwind and listening in average winds you can hear a slight swishing sound . . It's less than 60 ft from a power line that crosses the property but should the tower somehow fall in that direction it's impossible to strike the line before hitting the ground. Staying away for overhead wires is just common sense . . there are already adequate regulations for that.
On tower height a suggest 38.5 meter limit seems high enough. Generally I find even 75-80ft as adequate most of the time and towers (especially free standing tower) tend to get VERY expensive compared to cost of a small turbine when you go above that. When you start putting up 100-150ft towers and turbines with a capacity over 10kW you are not talking about personal wind systems anymore and you can't make a rule for the private personal systems that fits the commercial sized private turbines for farm or business use. when I say private turbine I mean those not designed to produce power for sale commercially. Private systems may produce 30-50Kw or more and still not "Sell" power commercially. They may well use it all themselves on a daily or monthly basis to offset their own consumption in a commercial enterprise, like a dairy farm or greenhouse business. That's why municipal planners need to consider far more than whether or not the power goes to the grid, before they call it commercial. . . and one regulation will not suffice for all the different users there are. I would guess there are at least as many as 4 or 5 different users that need different regulation.
Don't know why there should be any setbacks, at least for anchor points on guyed towers. Setting a tower back from lot lines at least half the height of the tower would serve to keep any but the most catastrophic tower failures within a property likely. any more than a fence generally. An anchor point in the ground is no different than a fence post and they typically go ON the lot line. A concrete anchor should not be considered a "foundation" either. It's no different than a fence post or flag pole anchor. You can even use "tethers" which is like a wire that goes down 4-6 feel to a dead man buried in the soil. . . or even an anchor screw in some cases if the soil is stable enough . . that does not make it a foundation, nor should it come under the same building code as house foundations. In a related area, a small wind turbine in not necessarily "Real Property" like an in ground pool so you can often take it with you like typical window air conditioner or above ground pool. this has been an issue for tax purposes, in Ontario at least.
As for size or distance from neighbouring buildings. The old 1/2 acre minimum is a throwback to the old days of big beasty "detroit iron" machines that did make a lot of noise and even sounded scary close up. I have many customers with smaller lots and machines quite close to their own dwelling with no ill effect either noise or safety.
As for radio or television interference again that's unlikely and an unnecessary since those concerns stem from the larger metal turbines of decades ago. I have seen no studies or evidence any small wind machines have EVER caused any interference.
Likewise with bats and birds . . I've installed over 100 small turbines myself and NEVER observed or even heard of a single bird kill documented by a small wind turbine . . those concern have been voiced by well meaning but misguided naturalists. I'm a birder myself since 1968 and only big windfarms have documented kills. Even those kill numbers are orders of magnitude less than a single glass building. . . and they are not taking any of those buildings down because of birds. Not an issue that needs to be regulated.
I did a presentation at CanWEA last year on Municipal and personal Planning for Small Wind and since then have had a number of municipal and private inquiries about what's good or practical about regulating private small wind installations in Ontario. I dare say many of these ideas apply equally but not completely in other jurisdictions. First of all, the definition of small wind is an issue. The category is simply too broad to apply across the board. For example in the Municipality of Northern Bruce where we are has somewhat arbitrarily defined “COMMERCIAL WIND ENERGY TURBINE” as meaning a structure designed to convert wind to useable energy for the purpose of inclusion into the electrical grid system. Right away that tells me they aren't aware of how personal wind systems can be "grid- tied" and capable of sending power into the grid yet they are not "Commercial" in any way. . . here are some additional considerations.
There is no reason to limit the lot size due to noise of towers. Many private homes have very large antenna towers for ham radio that may interfere with some radio signals but are allowed in most municipalities. As for noise, many small turbines are quite capable of producing good quiet power even when attached to the house. I never recommend that but it is quite often feasible. My experience, at least with stiff bladed turbines, is that in a quiet country setting the leaves in the trees make more noise that the turbine. Impossible to hear when there is any urban traffic. My 45ft tower and 3.5sq meter turbine is literally 2 feet from the corner of my house and yet I never hear it . . inside or outside the house. If you are downwind and listening in average winds you can hear a slight swishing sound . . It's less than 60 ft from a power line that crosses the property but should the tower somehow fall in that direction it's impossible to strike the line before hitting the ground. Staying away for overhead wires is just common sense . . there are already adequate regulations for that.
On tower height a suggest 38.5 meter limit seems high enough. Generally I find even 75-80ft as adequate most of the time and towers (especially free standing tower) tend to get VERY expensive compared to cost of a small turbine when you go above that. When you start putting up 100-150ft towers and turbines with a capacity over 10kW you are not talking about personal wind systems anymore and you can't make a rule for the private personal systems that fits the commercial sized private turbines for farm or business use. when I say private turbine I mean those not designed to produce power for sale commercially. Private systems may produce 30-50Kw or more and still not "Sell" power commercially. They may well use it all themselves on a daily or monthly basis to offset their own consumption in a commercial enterprise, like a dairy farm or greenhouse business. That's why municipal planners need to consider far more than whether or not the power goes to the grid, before they call it commercial. . . and one regulation will not suffice for all the different users there are. I would guess there are at least as many as 4 or 5 different users that need different regulation.
Don't know why there should be any setbacks, at least for anchor points on guyed towers. Setting a tower back from lot lines at least half the height of the tower would serve to keep any but the most catastrophic tower failures within a property likely. any more than a fence generally. An anchor point in the ground is no different than a fence post and they typically go ON the lot line. A concrete anchor should not be considered a "foundation" either. It's no different than a fence post or flag pole anchor. You can even use "tethers" which is like a wire that goes down 4-6 feel to a dead man buried in the soil. . . or even an anchor screw in some cases if the soil is stable enough . . that does not make it a foundation, nor should it come under the same building code as house foundations. In a related area, a small wind turbine in not necessarily "Real Property" like an in ground pool so you can often take it with you like typical window air conditioner or above ground pool. this has been an issue for tax purposes, in Ontario at least.
As for size or distance from neighbouring buildings. The old 1/2 acre minimum is a throwback to the old days of big beasty "detroit iron" machines that did make a lot of noise and even sounded scary close up. I have many customers with smaller lots and machines quite close to their own dwelling with no ill effect either noise or safety.
As for radio or television interference again that's unlikely and an unnecessary since those concerns stem from the larger metal turbines of decades ago. I have seen no studies or evidence any small wind machines have EVER caused any interference.
Likewise with bats and birds . . I've installed over 100 small turbines myself and NEVER observed or even heard of a single bird kill documented by a small wind turbine . . those concern have been voiced by well meaning but misguided naturalists. I'm a birder myself since 1968 and only big windfarms have documented kills. Even those kill numbers are orders of magnitude less than a single glass building. . . and they are not taking any of those buildings down because of birds. Not an issue that needs to be regulated.
Batteries - Flooded vs Valve Regulated Lead Acid?
There's lots of good information from the Surrette/Rolls battery people and Trojan Battery as well as other well know brands about renewable energy batteries and how they are different from car and truck batteries. And manufacturers however, tend not to recommend you check with other suppliers to see why you should chose one battery technology over another. There is also little written generally on why one would choose other technologies, unless you google it (Flooded vs VRLA) and then there are only about 6 links. This is mostly because until recently VRLA batteries were only commonly used in expensive telecom applications.
Basically, all batteries have acid. It's the chemical conversion of lead and lead sulfates that store and release electrons at the molecular level. The flooded ones have acid in liquid form and two others . . the absorbed glass mat (AGM) battery and the Gel technology batteries have an acid paste or gel and can be valve regulated so they produce virtually no dangerous fumes compared to the flooded cells. Flooded batteries normally produce both hydrogen and oxygen when they are working and so need to be vented to the outside to prevent any health or safety hazard. The sulfuric acid inside teh cells can also spill and cause a serious burn, corrosion or caustic hazard. On the other hand, VRLA batteries can be in unvented enclosed spaces and don't require to having their fluids topped up regularly or specific gravity checks done like the flooded ones do. Don't do the maintenance and you are wasting you money no matter which one you buy but VRLAs require a lot less work and less often.
Flooded Lead Acid . . . . . . . . . . . . . . . . . . . . . . . . . . . VRLA Batteries
[missing photos x3]
There's lots of good information from the Surrette/Rolls battery people and Trojan Battery as well as other well know brands about renewable energy batteries and how they are different from car and truck batteries. And manufacturers however, tend not to recommend you check with other suppliers to see why you should chose one battery technology over another. There is also little written generally on why one would choose other technologies, unless you google it (Flooded vs VRLA) and then there are only about 6 links. This is mostly because until recently VRLA batteries were only commonly used in expensive telecom applications.
Basically, all batteries have acid. It's the chemical conversion of lead and lead sulfates that store and release electrons at the molecular level. The flooded ones have acid in liquid form and two others . . the absorbed glass mat (AGM) battery and the Gel technology batteries have an acid paste or gel and can be valve regulated so they produce virtually no dangerous fumes compared to the flooded cells. Flooded batteries normally produce both hydrogen and oxygen when they are working and so need to be vented to the outside to prevent any health or safety hazard. The sulfuric acid inside teh cells can also spill and cause a serious burn, corrosion or caustic hazard. On the other hand, VRLA batteries can be in unvented enclosed spaces and don't require to having their fluids topped up regularly or specific gravity checks done like the flooded ones do. Don't do the maintenance and you are wasting you money no matter which one you buy but VRLAs require a lot less work and less often.
Flooded Lead Acid . . . . . . . . . . . . . . . . . . . . . . . . . . . VRLA Batteries
[missing photos x3]
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So why would I use one or the other in my renewable energy system? Basically it comes down to cost and convenience. It used to be that VRLAs were over twice the price of equivalent Floodeds. Now, they are pretty comparable in price for the same Amp Hours capacity and most people world rather just monitor the voltage twice a year rather than check the fluids once an month and check fluids and specific gravity of every cell 4 times a year as is needed for the floodeds. . . More importantly, the peace of mind that they don't produce any dangerous gases is enough incentive for most users to specify VRLA. VRLA also tolerate the cold more than flooded because the paste remains more acidic even when in a low charge state. When the acid gets weak from being discharged flooded batteries are prone to freezing and that's usually permanent damage. Intuitively though, you have to expect some loss in capacity at low temperature simply because it's a chemical reaction that works better at normal (70 degF) temperatures.
If you currently own VRLA batteries here are some quick "rule of thumbs" for charging. Please check with the manufacturer if you can for more the specific needs of you battery.
In GENERAL:
High Rate of Charge at 10% of the AH rating - at a max of 2.4 volts/cell
Low Rate of Charge at 3% of the AH rating - max of 2.35 volts/cell
Finishing or float Charge at 1% of the AH rating - max of 2.25 volts/cell
Robert Wittemann is Senior Product Manager of Telecom and Bruce Dick is Director of Product Management at C&D Technologies, Blue Bell, Pa.. Together they published an excellent technical discussion in 1998 on this very subject. Improvements in technology in the past 7 years now are making VRLA an even better choice. For those who want the full details CLICK HERE. If you can't find a good supplier call me (519) 793-3290
If you currently own VRLA batteries here are some quick "rule of thumbs" for charging. Please check with the manufacturer if you can for more the specific needs of you battery.
In GENERAL:
High Rate of Charge at 10% of the AH rating - at a max of 2.4 volts/cell
Low Rate of Charge at 3% of the AH rating - max of 2.35 volts/cell
Finishing or float Charge at 1% of the AH rating - max of 2.25 volts/cell
Robert Wittemann is Senior Product Manager of Telecom and Bruce Dick is Director of Product Management at C&D Technologies, Blue Bell, Pa.. Together they published an excellent technical discussion in 1998 on this very subject. Improvements in technology in the past 7 years now are making VRLA an even better choice. For those who want the full details CLICK HERE. If you can't find a good supplier call me (519) 793-3290
New Compact E-Panels
Outback Power systems has produced a very nicely integrated PS2 panel that looks like this:
Outback Power systems has produced a very nicely integrated PS2 panel that looks like this:
But many users find it takes up a lot of space and they don't plan to add a second inverter very soon so it's always been rather expensive and bulky to use the PS2 configuration in all cases. More than once I've struggled to find a space big enough to place the PS2 board and still have access room around all sides. Now we have a new configuration called the E-Panel that is designed for only one inverter MATE and maybe an MX60 with all the necessary switches and breakers. It's compact and accessible and better than that about $1000 less than a PS2 panel configured for only one inverter. You can also configure it in grid tied or off grid or use the less expensive modified sine wave MagnaSine inverter up to 4kW power output. You can't do dual voltage 110-220 output without a second transformer but they come completely configured in 2kw12v for as little as $3,500 Canadian with CSA safety approvals and lightning arrestors
I think we'll see a lot of these this year
I think we'll see a lot of these this year
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