Being a mechanical engineering,I understood the fundamental formula and found the best of best video till date,,I have watched more than 200 videos, but none was able to provide me the fundamental details,, You cleared all my doubts in this single video,and helped me save my money because I was seriously considering to install few small vertical axis turbine on my factory building,, as an substitute to solar panels,,but my place is not so suitable for proper functioning,, So, thanks a lot for such a great video,, I have subscribed your channel,,👍👍👍👍
Very well done, congratulations and thank you. We need far more University scientific wind courses like this! from RH Henkle large wind energy professional.
I have a question, preceeded by some explanation of how I understand the technology. Which could be wrong... I've looked at the technical data sheets of several wind turbines, from 10kW up through 3mW. As I understand it, wind turbines (small and large) don't produce full power until the wind is about 25mph. At half speed 12.5mph they output about 1/8th power (12.5%) and at 9mph their output is zero. I called a decent sized wind farm here in the midwest and the manager was quite nice and fairly transparent. Of course their website stated the benifit of the site at 100% output, but after some prodding, the manager conceded that the output was much less, putting it at 10% to 13%. My question: I've done some back of napkin calculations on smaller turbines (which I can get prices on) and with the price of equipment, and installation, I can't see any way to make the smaller ones pay for themselves, even at the retail cost of power. Assuming the cost per kw is fairly linear for land based turbines, of which I'm unsure; I then consider the viability of commercial wind farms. Once you add in land cost, maintenance, insurance, taxes, and management costs, how is it possible for wind to be a cost effective technology? Financially, it just seems untenable. Am I off?
There is a way to make the Darieus windturbine more usefull. The vertical windturbine has a disadvantage in the southern oceaans that the Darieus can solve. Use the Darieus on its V3 with producing H2. The Darieus has the advantage of a more easy way of adding turbines, when windspeeds go up. Use the more Kg with higher windspeeds forces to pull more turbines at a equal speed, so no brakes or shud downs are needed when storm windforces arrive, you just let the Darieus spin more turbines. 1 big on vertical vs 4 to 8 smaller, depending on windforce. On the vertical windblades higher speeds will stress the material more by its centrifugal force on big turbines and using brakes or shut them down is a waste of energie. When bild well, you can use a part of the energie for electric magnetism to let it hoover so there is less fricktion, but a faillure in that system could make the whole turbine crash. I'ff you create a bigger vacuum behind the blades, will the drag increase or decrease? I mean... High pressure tent to flow to low pressure, does it not? ;0)
I'm working on college project. Following your formula I've work out that my wind turbine can produce 15.7 watts. Power in the wind (Watts) (p)= 1/(2 ) 𝑝A 𝑣^3 𝑝 = Density of Air = 1.2 kg/ 𝑀^3 V = Velocity = 7 m/s A = Area = 2 π X r X h = (2)(π)(1)(.3) =1.9 𝑀^3 P = (1/(2 ))(1.2)(1.9 x 2)(7) = 15.96 Watts Does that mean 15.96 watts a second ? so to work out my out my power out for the day would 15.7 x 60 x 60 x 24 / 1000 would that give me kilowatt hours seem like a very big number ?
You should divide by 3,600,000, rather than 1,000. This is because one kWh is equal to 3,600,000 joules. You asked "Does that mean 15.96 watts a second?". A watt is a unit of power, and is equal to one joule per second. So you shouldn't think in terms of watts per second, but rather, joules per second. 15.96 watts is 15.96 joules per second. You can remember that one kWh is equal to 3,600,000 joules by remembering that a watt is equal to one joule per second. So, a kWh, is 1000 watts, over the course of an hour. An hour is 3,600 seconds. Multiply that by 1,000, which is how you'll see that 1 kWh is equal to 3,600,000 joules.
Interesting video. I'm building my own windturbine including the generator but I was initially planning to set it up on a roof. But I know I should'nt do that. It's also more complicated and dangerous to install it by yourself on a roof of a traditional house. Put the wind turbine on a tower is easyer to do. Thanks.
I have a question about the formula: P = pAV^3 if we only look at how this formula affects horizontal axes turbines then we will only get an answer about that one type of turbine, but can't we apply this formula to turbines in general? If we do apply this formula to all turbines it would seem that the larger the Area of the turbine the greater the power generated, therefore, it seems to me that of all 3 types of turbines the Savonious has the larger swept surface area and therefore makes more potential energy. Please correct me if I am wrong. The way I see it the larger the sail on the boat the faster it will go.
You are confusing surface are to swept area. Turbines with high surface area are said to have high solidity, Savonious or even old water pumping wind mills. Modern HAWT have large swept area but low surface area and are said to have low solidity. The swept area is the important number to consider here. If the two were the same swept area the Wind power would be the same based on the equation then we need to take into account the efficiency of how each convert that wind "power" into rotational "power" and then Electrical "power". I put "power" in quotes here only because I did not want to switch between power and energy. We know each type will not likely approach 59% efficiency, yet the savonious's slow spinning (mostly drag machine) wastes a lot of power causing the air behind to swirl. The faster spinning (due to lift forces) HAWT creates less swirl and is thus more efficient.
@@CropWatchBioenergy Thank you so much for helping me understand wind turbine questions. I misused the term "swept area" when what I really was trying to talking about was turbines with high solidity. I have a design that doubles the efficiency of the average Savonious turbine, that might count for something. I don't know if it would be better then the Horizontal axis turbine but will have to test it out.
Mark, Good luck with your design. I think there is room for improvement. I think all designs might have their niche. The proof of any design is in the production.
Another thing to consider is the aerodynamics of the machine as savonius is a drag machine and a three-bladed wind turbine is a lift machine. Drag machines can only take advantage of half the wind speed due to the effect of apparent wind felt by the machine. A lift machine uses a cross wind much like a sail on a boat making the most of the incoming wind speed.
THANK YOU FOR YOUR VIDEO. Can I make a few small turbines and connect them to a controller and save them into a battery. All I need is to make 1200W and how many turbines do I need and the smallest in size can accomplish it.
What is the up to date take on wind turbine tail feather ? Buy the way thank you for the informative post , Where I now live is to become wind farm central , with 34 turbines around 200 meters blade tip height . Closest about 250 meters away but all within 9 k`s .
Glad you liked it. There are a lot turbines out there trying to sell their new "design". Low efficiency turbines are not inherently bad, but saying they can generate more than they are capable of is bad. Good luck
@@CropWatchBioenergy can u suggest any reasonably modest wind turbine design using 200-300watts alternator and if so what height would u recommend it b put and what min winds speeds r must that u reasonably shd have
There is something wrong with Betz limit if kinetic energy in the wind is 1/2 mass then where can the Betz 0.926% come from regards Graham Flowers MEng
Power is in units of Watts, A Watt = Joule/Second, if the power is multiplied times a unit of time seconds cancel and the unit is Joule which is a unit of Energy. Usually electricity is metered in kilowatt or megawatts for power and kilowatthours or megawatthours for energy
But the most eficient for low wind speed you have some experince? On Highway in the midle at least in Europe when are smaller wich one of vertical tourbine is better Savonious o Darrieus? Take in mind the wind is produces only by cars when passin close to it. Max speed 120km/h of the car maybe can produce 10km/h of wind speed
The conversion to mass (for KE= /2*m*v^2) from density and area needs another dimension: length to create a volume. This comes from velocity as a given mass passes thru A in unit time. However using v assumes v goes from incident v to zero as it passes the turbine. It does not, it becomes turbulent. If incident v = exit v then no reduction of KE has occurred. Application of this equation will always yield an inefficiency IF the input assumes v = 0 as it exits the turbine, which is impossible. Why doesn't anyone comment on this?
Thanks for your comments. I intended this as a basic overview. The Betz limit and calculations can help with the how much the wind can be slowed (not stopped) for an ideal turbine. Good points regarding the wind not stopping and becoming turbulent behind the blades.
¿Is it true that Vertical Axis Wind Turbines these Vertical Axis Wind Turbines are more stable in high speed winds than horizontal turbines and safer for animals like birds and bats?
Design and balance has a lot to do with stability. The challenge as I see it is the fact that higher tip speed translates to higher efficiency yet higher tip speed is a problem for wildlife. If the blades spun slow they would be less danger but also less efficient. Birds and bats are mostly a problem when wind turbines are built in locations where there are large numbers of animals. Specifically of concern are threatened and endangered birds and bats. State and national wildlife experts get involved with wind farm siting to help select sites with fewer bird bat interactions.
Can someone please explain why a house-wind-turbine looses efficiency (slows down) when energy demand is increased (ie: a microwave is used?). What is that called? Thanks.
Can you estimate the diameter of a wind turbine foundation by considering its rotor diameter and tower height? I am thinking about a gravity based foundation.. I once spoke to a wind guy and he told me it is possible to calculate and then he left off.
Betz limits ? based on wind/hydro energy losses between the blades A Phyics Law.set in in the oil promotion era 1919. Claiming all windmills are the same.! even My1986 patented Lonien windmill that has 0 gaps . Instead it pivots the flat blades to oppose its own infinately thin Blades( Infinatly Horrizontal) the facts remain uninvestigated. does this Equa and opposite design disprove Betz Limits ?.and mimic Einestines equal and Opposite reactions capable of .infinate energy values.?
exactly, if you come to an engineering solution then it makes the designs made before obsolete, like pivoting the blade's, there are ways to make a good design work with an even better creative design so the Betz law does not come into it as we are all after horsepower, space, easy practical design
Thanks, I have talked people out of investing on bad designs with application of just these simply physics equations. These equations combined with the first and second laws of thermo are powerful. A turbine does not generate more than the power in the wind hitting the swept area.
What if you redirected man made wind to impact only the tip of the blade extensions perpendicularly and those blades were riding in a vortex? I am seeking a formula for efficiency in a prototype design where Betz's limit does not apply.
Hello, what is unit of time of watt/m2? at 2:25? graphic shows we can get approx 900 watt at 12 m/s with 1 m2. is it in one turn or 1 minute or 1 hour or 1 year? and how many turns? thanks for your answer.
Watts on the vertical axis, Wind speed on the horizontal axis. A Watt is a Joule per second. If the wind were to blow at 12 m/s for one hour the 1 sq meter turbine could access 900 Watthours of energy. It can convert less than 59% of that into rotational energy and even less than that into electrical energy. 900 Watthours is 0.9 kWh and with the inefficiencies listed above the turbine may realistically be able to generate 0.3 kWh after spinning for one hour in a 12 m/s wind. A small horizontal axis turbine may spin the generator at over 200 RPM at a 12m/s wind speeds. This will vary by turbine design and blade shape and pitch.
Have agood day I have a question I hope that I find you have response your capacity as specialized in the wind turbines . If the wind power that runs the blades for example, 100 hp , or 100 Newton the number of cycles entering into gearbok and then to the generator fixed and stable the output electric current good and stable in terms of voltages , ampere .. the question here ,The amount of energy entering the gearbox and then to the generator of 100 horsepower or 100 Newton how much horsepower or newton Newton will come out net of the generator representative of electricity after calculate factor friction and heat intersection magnetic fields in the generator . I hope to answer my question with thank ..
How about cluster of smaller turbines (for ex. 500w), will they work for let say 2-5kW use? Probably again same problem of turbulence and all that right? Is turbulence same from vertical or horizontal turbine? And some additional question, if somebody knows: is there some use of wind and solar together for more efficient energy use for home (maybe even with on-grid system)?
Do the thickness and width of a blade affect in any way the efficiency of a turbine? I see that only the swept area is taken into account (height and rotor diameter). What if the blade is too thin and narrow?
Blade thickness and weight has nothing to add to efficiency, because entire efficiency depends on weight of air pushing the blades to rotate,, And I learned this fundamental from this video
we want to know the kinetic energy of wind in kwh at different wind speeds + or - 2 percent or is that beyond you. mail to getqldzuca@icloud.com. thanks
Excellent lecture.I would have also liked a bit of information about i) the blade shape and pitch, ii) whether a gearing is generally advantageous and iii) some mention of ideal generator - but I guess the latter two points do not fall under the scope of the title. Having said that, I think most people (myself included) tend to put too much emphasis on these topics and not enough on the wind power aspects that are very clearly laid out in the lecture. I, like others, had to learn the proportionality of power to the cube of the wind speed the hard way. I kept redesigning in the vain attempt to get more power from low wind speeds - where there simply is no significant power to be attained :-(
Generally with well designed blades fewer is better (yet balance to reduce stresses has led to many having 3). I don't think there is anything that says a turbine could not have more blades only that more have not proven better, yet.
The derivation at 2:01 should use lowercase "v" for mass flow rate... it is conflated with volume which makes it confusing when it's plugged in to solve for kinetic energy,
My guess is that the turbine has a tail, like most others. However, the picture, is such that it's hard to recognize the tail. I think the orientation of the turbine, makes the tail more difficult to see.
Yes the blade speed does matter. The revolutions per minute of large wind turbines will vary by design. Many turbine designs maintain a constant RPM to synchronize with the grid. The speed of the blade tip does matter as higher tip speeds generally results in higher efficiency. Small wind turbines generally spin faster at higher wind speeds and take the "wild" electricity and "clean" using power electronics.
So all those small turbines they are trying to sell, doesn't do much. The cost to install it with its own AC generator and inverter , and a battery for storage, isn't justifiable.
The economics of small wind turbines is poor. High cost of turbines, repair and maintenance. Payback longer than useful life is what I would expect. Yet there are applications where they may be useful. An offgrid home charging batteries might benefit from a combination of wind and solar. If you are off grid economics might be less important.
Excellent description of Air as Kinetic wind energy as Force from an actual Mass and it`s Acceleration. KE = 1/2 M x V squared. I think of it sometimes that we are fishing in a great ocean of air, catching and releasing billions of molecular fish with a large Rotor Blade Net. No bloodletting, no pain, Clean.
Anybody can calculate how much watt i can get with in one hour? Blade height 6mt, blade with 1m, distance from blade to blade 12mt, total blade count 10. wind speed avg. 10 m/s and r/p/m is 60. Thanks.
The actual energy production of your turbine needs to be measured. Yet we can make some simple calculations. Wind turbine with Diameter of 12 meters. Wind speed of 10m/s and 60 RPM The power in the wind available to the turbine is about 56,500 Watts or 56.5 kW. This is a small turbine and efficiency is likely only moderate considering a tip speed ratio of ~3/1. With a 20% efficiency this turbine would generate 14 kWh in one hour of operation. In reality I would expect less since your high blade count adds to the solidity of the turbine giving you torque lower speed (rpm). Higher tip speeds lead to higher efficiency for electric generating turbines. Fewer blades will require higher wind speed to start low wind speed are low power so it doesn't matter much.
You don't give any formula that shows the relation of high wind speed on the design of the turbine. It's not that I don't believe you but just the same. Thank you for this very informative video.
Glad you liked it. I intentionally kept this simple. Wind turbines will gradually become less efficient as wind speed increases in order to maintain their RPM and at high wind speed may even shut off to protect themselves.
The answer to wind turbines is that they are now unnecessary. We now have the ultimate and cheapest green power device with none of these problems, in the SAFIRE GENERATOR. This is what we need to negate all the problems of all competing green energies. It produces almost costless electricity and therefore hydrogen from new FUSION NUCLEAR and is now immediately upon us. We have recently taken a new step to advance the physic of medium temperature plasma fusion power production by enabling chemistry of the atomic nucleus, or "nuchemy" in the newest FUSION NUCLEAR POWER technology. We are passing the chemistry level where we interacted with the atomic electron shells and are moving on to manipulations in this "NUCHEMY" atomic nuclear era when we interact and multiply nuclear protons. We have rediscovered the lost work of the alchemists and can make new elements with different atomic weights. This was ably demonstrated in "THE SAFIRE PROJECT". Quanta are important. We now have enough energy to manipulate the atomic nucleus much more easily by creating a compartment, or what is a local region of plasma containment so reactions at this atomic nuclear level can easily take place. This is about to practically enabled a really fantastic and cheap new era of energy production for the whole of mankind. This with hydrogen, so free fuel obtained from water or atmospheric moisture anywhere in the world. This new fusion nuclear SAFIRE GENERATOR is at the industrial commercial production final development point as of now and it can retrofit older and decommissioned power plants. The energy argument and other power methodologies are all now virtually irrelevant as we have new and very physically and economically powered practical and local community level fusion nuclear power. Solar roof plus Teslawall battery may be the present way to go domestically but megapack batteries and multiple storage technologies interconnected with an expanded ugly grid have a less certain requirement when you consider new any-scale community based and 24 hr reliable and self-fueling fusion nuclear in the form of the "SAFIRE REACTOR". Learn all about it at "AUREON @t". Then learn the newer EU Theory and plasma physics at "THUNDERBOLTS @t" and you will be permanently reeducated with this advanced newer EU theory that will allow you to understand more about the astrophysics of our whole universe and all within and you will be more informed and can teach your peers.
Hi Sir, this is a wind energy problem "Given a wind speed of 8𝑚 𝑠 and a blade tip speed ratio of 3. Calculate the blade chord angle at radius ratios 𝑅′ of 0.2, 0.6 & 1 for 1.An angle of attack of 0degree.2. An angle of attack of 16degrees." I would be grateful if u could help me out by solving this problem as I didn't understand this problem but found it similar to your videos
You can use the formula for power in the wind and solve for rotar diameter based on a given wind speed. 3kw is going to be in the 15 to 20 ft dia range at low wind speeds.
I would be interested to see the real data. I am skeptical about the actual production vs estimated. I would expect they produce much less than expected.
This was a very clear explanation of wind physics. Thank you for putting it out here as a public resource!
Being a mechanical engineering,I understood the fundamental formula and found the best of best video till date,,I have watched more than 200 videos, but none was able to provide me the fundamental details,,
You cleared all my doubts in this single video,and helped me save my money because I was seriously considering to install few small vertical axis turbine on my factory building,, as an substitute to solar panels,,but my place is not so suitable for proper functioning,,
So, thanks a lot for such a great video,,
I have subscribed your channel,,👍👍👍👍
Very well done, congratulations and thank you. We need far more University scientific wind courses like this!
from RH Henkle large wind energy professional.
Thank you for very interesting thoughts and discussions, very helpful for my PhD studies in foundation engineering
Excellent video, very well explained. Thank you for making it.
Holy crap at 7:38 you became briefly possessed by Yoda
Tim Carr M. N n bn m. Nb b. B. N. M n n n. N man. B n. M
LOL
omg LOL !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I have a question, preceeded by some explanation of how I understand the technology. Which could be wrong...
I've looked at the technical data sheets of several wind turbines, from 10kW up through 3mW. As I understand it, wind turbines (small and large) don't produce full power until the wind is about 25mph. At half speed 12.5mph they output about 1/8th power (12.5%) and at 9mph their output is zero.
I called a decent sized wind farm here in the midwest and the manager was quite nice and fairly transparent. Of course their website stated the benifit of the site at 100% output, but after some prodding, the manager conceded that the output was much less, putting it at 10% to 13%.
My question: I've done some back of napkin calculations on smaller turbines (which I can get prices on) and with the price of equipment, and installation, I can't see any way to make the smaller ones pay for themselves, even at the retail cost of power.
Assuming the cost per kw is fairly linear for land based turbines, of which I'm unsure; I then consider the viability of commercial wind farms.
Once you add in land cost, maintenance, insurance, taxes, and management costs, how is it possible for wind to be a cost effective technology? Financially, it just seems untenable.
Am I off?
THAT, was well done. You included issues that other wind turbine vids haven't even touched on.
Thank you so much , it was a simple and clear explanation.
This is an example of an objective and clear explanation.
Excellent lecture! Clear and easy to understand!
There is a way to make the Darieus windturbine more usefull. The vertical windturbine has a disadvantage in the southern oceaans that the Darieus can solve. Use the Darieus on its V3 with producing H2. The Darieus has the advantage of a more easy way of adding turbines, when windspeeds go up. Use the more Kg with higher windspeeds forces to pull more turbines at a equal speed, so no brakes or shud downs are needed when storm windforces arrive, you just let the Darieus spin more turbines. 1 big on vertical vs 4 to 8 smaller, depending on windforce. On the vertical windblades higher speeds will stress the material more by its centrifugal force on big turbines and using brakes or shut them down is a waste of energie. When bild well, you can use a part of the energie for electric magnetism to let it hoover so there is less fricktion, but a faillure in that system could make the whole turbine crash. I'ff you create a bigger vacuum behind the blades, will the drag increase or decrease? I mean... High pressure tent to flow to low pressure, does it not? ;0)
I'm working on college project.
Following your formula
I've work out that my wind turbine can produce 15.7 watts.
Power in the wind (Watts) (p)= 1/(2 ) 𝑝A 𝑣^3
𝑝 = Density of Air = 1.2 kg/ 𝑀^3
V = Velocity = 7 m/s
A = Area = 2 π X r X h
= (2)(π)(1)(.3) =1.9 𝑀^3
P = (1/(2 ))(1.2)(1.9 x 2)(7)
= 15.96 Watts
Does that mean 15.96 watts a second ?
so to work out my out my power out for the day would
15.7 x 60 x 60 x 24 / 1000
would that give me kilowatt hours
seem like a very big number ?
You should divide by 3,600,000, rather than 1,000. This is because one kWh is equal to 3,600,000 joules.
You asked "Does that mean 15.96 watts a second?". A watt is a unit of power, and is equal to one joule per second. So you shouldn't think in terms of watts per second, but rather, joules per second. 15.96 watts is 15.96 joules per second.
You can remember that one kWh is equal to 3,600,000 joules by remembering that a watt is equal to one joule per second. So, a kWh, is 1000 watts, over the course of an hour. An hour is 3,600 seconds. Multiply that by 1,000, which is how you'll see that 1 kWh is equal to 3,600,000 joules.
You said regardless the 3 the power is what it is. What if there was a 4th option? I found one.
Interesting video.
I'm building my own windturbine including the generator but I was initially planning to set it up on a roof. But I know I should'nt do that. It's also more complicated and dangerous to install it by yourself on a roof of a traditional house. Put the wind turbine on a tower is easyer to do. Thanks.
I have a question about the formula: P = pAV^3 if we only look at how this formula affects horizontal axes turbines then we will only get an answer about that one type of turbine, but can't we apply this formula to turbines in general? If we do apply this formula to all turbines it would seem that the larger the Area of the turbine the greater the power generated, therefore, it seems to me that of all 3 types of turbines the Savonious has the larger swept surface area and therefore makes more potential energy. Please correct me if I am wrong. The way I see it the larger the sail on the boat the faster it will go.
You are confusing surface are to swept area. Turbines with high surface area are said to have high solidity, Savonious or even old water pumping wind mills. Modern HAWT have large swept area but low surface area and are said to have low solidity. The swept area is the important number to consider here. If the two were the same swept area the Wind power would be the same based on the equation then we need to take into account the efficiency of how each convert that wind "power" into rotational "power" and then Electrical "power". I put "power" in quotes here only because I did not want to switch between power and energy. We know each type will not likely approach 59% efficiency, yet the savonious's slow spinning (mostly drag machine) wastes a lot of power causing the air behind to swirl. The faster spinning (due to lift forces) HAWT creates less swirl and is thus more efficient.
@@CropWatchBioenergy Thank you so much for helping me understand wind turbine questions.
I misused the term "swept area" when what I really was trying to talking about was turbines with high solidity. I have a design that doubles the efficiency of the average Savonious turbine, that might count for something. I don't know if it would be better then the Horizontal axis turbine but will have to test it out.
Mark, Good luck with your design. I think there is room for improvement. I think all designs might have their niche. The proof of any design is in the production.
Another thing to consider is the aerodynamics of the machine as savonius is a drag machine and a three-bladed wind turbine is a lift machine. Drag machines can only take advantage of half the wind speed due to the effect of apparent wind felt by the machine. A lift machine uses a cross wind much like a sail on a boat making the most of the incoming wind speed.
THANK YOU FOR YOUR VIDEO. Can I make a few small turbines and connect them to a controller and save them into a battery. All I need is to make 1200W and how many turbines do I need and the smallest in size can accomplish it.
What is the up to date take on wind turbine tail feather ? Buy the way thank you for the informative post , Where I now live is to become wind farm central , with 34 turbines around 200 meters blade tip height . Closest about 250 meters away but all within 9 k`s .
Great presentation. Thanks for saving me money by investing in the wrong turbine.
Glad you liked it. There are a lot turbines out there trying to sell their new "design". Low efficiency turbines are not inherently bad, but saying they can generate more than they are capable of is bad. Good luck
@@CropWatchBioenergy can u suggest any reasonably modest wind turbine design using 200-300watts alternator and if so what height would u recommend it b put and what min winds speeds r must that u reasonably shd have
It's interesting to see different realities expressing one's interpretation based on one's limited frame of reference.
great, giving practical examples of good and bad selections
There is something wrong with Betz limit if kinetic energy in the wind is 1/2 mass then where can the Betz 0.926% come from regards Graham Flowers MEng
Fantastic info mate. Exactly what I was looking for
Excellent explanation for basics. Thank you. I am now trying to find the extension of the energy calculations which includes losses.
Straightforward explanation, thank you !
Hi, calculated wind power is for one day or one hour?
Power is in units of Watts, A Watt = Joule/Second, if the power is multiplied times a unit of time seconds cancel and the unit is Joule which is a unit of Energy. Usually electricity is metered in kilowatt or megawatts for power and kilowatthours or megawatthours for energy
I love this video helped me on a project im working on
>
So tell us what you found!
mean while a set of flat blades set on common shaft 45 degrees opposing its opposite half can and will produce infinite values
But the most eficient for low wind speed you have some experince?
On Highway in the midle at least in Europe when are smaller wich one of vertical tourbine is better Savonious o Darrieus? Take in mind the wind is produces only by cars when passin close to it.
Max speed 120km/h of the car maybe can produce 10km/h of wind speed
Never even remotely efficient enough to pay for building it
Thank you for informing us about wind turbans.
Turbines is what I am saying yet it does sound like turbans sometimes
Hej, great video. Does anybody know the name of the person talking, need that for school...
the wind pushes on what it touches it can't push on the gaps between the blades regards Graham Flowers
The conversion to mass (for KE= /2*m*v^2) from density and area needs another dimension: length to create a volume. This comes from velocity as a given mass passes thru A in unit time. However using v assumes v goes from incident v to zero as it passes the turbine. It does not, it becomes turbulent. If incident v = exit v then no reduction of KE has occurred. Application of this equation will always yield an inefficiency IF the input assumes v = 0 as it exits the turbine, which is impossible. Why doesn't anyone comment on this?
Thanks for your comments. I intended this as a basic overview. The Betz limit and calculations can help with the how much the wind can be slowed (not stopped) for an ideal turbine. Good points regarding the wind not stopping and becoming turbulent behind the blades.
¿Is it true that Vertical Axis Wind Turbines these Vertical Axis Wind Turbines are more stable in high speed winds than horizontal turbines and safer for animals like birds and bats?
Design and balance has a lot to do with stability. The challenge as I see it is the fact that higher tip speed translates to higher efficiency yet higher tip speed is a problem for wildlife. If the blades spun slow they would be less danger but also less efficient. Birds and bats are mostly a problem when wind turbines are built in locations where there are large numbers of animals. Specifically of concern are threatened and endangered birds and bats. State and national wildlife experts get involved with wind farm siting to help select sites with fewer bird bat interactions.
Can someone please explain why a house-wind-turbine looses efficiency (slows down) when
energy demand is increased (ie: a microwave is used?). What is that called? Thanks.
Can I use the same formula for a vertical axis water turbine? Is it just as simple as replacing the density of air by the density of water?
Where does the number of blades factor into the equation(s) ?
Can you estimate the diameter of a wind turbine foundation by considering its rotor diameter and tower height? I am thinking about a gravity based foundation.. I once spoke to a wind guy and he told me it is possible to calculate and then he left off.
Betz limits ? based on wind/hydro energy losses between the blades A Phyics Law.set in in the oil promotion era 1919. Claiming all windmills are the same.! even My1986 patented Lonien windmill that has 0 gaps . Instead it pivots the flat blades to oppose its own infinately thin Blades( Infinatly Horrizontal) the facts remain uninvestigated. does this Equa and opposite design disprove Betz Limits ?.and mimic Einestines equal and Opposite reactions capable of .infinate energy values.?
exactly, if you come to an engineering solution then it makes the designs made before obsolete, like pivoting the blade's, there are ways to make a good design work with an even better creative design so the Betz law does not come into it as we are all after horsepower, space, easy practical design
i liked the demontration,
how to simulate the power of the wind turbine using matlab?
This video makes people waste less money. =)
Everyone experimenting with wind power should watch this first to get a good start!
Thanks, I have talked people out of investing on bad designs with application of just these simply physics equations. These equations combined with the first and second laws of thermo are powerful. A turbine does not generate more than the power in the wind hitting the swept area.
What if you redirected man made wind to impact only the tip of the blade extensions perpendicularly and those blades were riding in a vortex? I am seeking a formula for efficiency in a prototype design where Betz's limit does not apply.
In wind turbine in which all areas we can design it
Hello, what is unit of time of watt/m2? at 2:25?
graphic shows we can get approx 900 watt at 12 m/s with 1 m2.
is it in one turn or 1 minute or 1 hour or 1 year? and how many turns?
thanks for your answer.
Watts on the vertical axis, Wind speed on the horizontal axis. A Watt is a Joule per second. If the wind were to blow at 12 m/s for one hour the 1 sq meter turbine could access 900 Watthours of energy. It can convert less than 59% of that into rotational energy and even less than that into electrical energy. 900 Watthours is 0.9 kWh and with the inefficiencies listed above the turbine may realistically be able to generate 0.3 kWh after spinning for one hour in a 12 m/s wind. A small horizontal axis turbine may spin the generator at over 200 RPM at a 12m/s wind speeds. This will vary by turbine design and blade shape and pitch.
Have agood day
I have a question I hope that I find you have response your capacity as specialized in the wind turbines .
If the wind power that runs the blades for example, 100 hp , or 100 Newton the number of cycles entering into gearbok and then to the generator fixed and stable the output electric current good and stable in terms of voltages , ampere .. the question here ,The amount of energy entering the gearbox and then to the generator of 100 horsepower or 100 Newton how much horsepower or newton Newton will come out net of the generator representative of electricity after calculate factor friction and heat intersection magnetic fields in the generator .
I hope to answer my question with thank ..
How about cluster of smaller turbines (for ex. 500w), will they work for let say 2-5kW use? Probably again same problem of turbulence and all that right? Is turbulence same from vertical or horizontal turbine? And some additional question, if somebody knows: is there some use of wind and solar together for more efficient energy use for home (maybe even with on-grid system)?
please can you provide some more details regarding it we are making a project.
Sir can you explain how to calculate deflection of vertical wind turbine..?
Sorry, no I can't help with this.
run it on FEA
Do the thickness and width of a blade affect in any way the efficiency of a turbine? I see that only the swept area is taken into account (height and rotor diameter). What if the blade is too thin and narrow?
Blade thickness and weight has nothing to add to efficiency, because entire efficiency depends on weight of air pushing the blades to rotate,,
And I learned this fundamental from this video
Thanks so much, really good thorough explanation.
we want to know the kinetic energy of wind in kwh at different wind speeds + or - 2 percent or is that beyond you. mail to getqldzuca@icloud.com. thanks
Excellent lecture.I would have also liked a bit of information about i) the blade shape and pitch, ii) whether a gearing is generally advantageous and iii) some mention of ideal generator - but I guess the latter two points do not fall under the scope of the title. Having said that, I think most people (myself included) tend to put too much emphasis on these topics and not enough on the wind power aspects that are very clearly laid out in the lecture. I, like others, had to learn the proportionality of power to the cube of the wind speed the hard way. I kept redesigning in the vain attempt to get more power from low wind speeds - where there simply is no significant power to be attained :-(
What about the ratio between the coils and neodium magnets and blade size
does it matter if we increase the number of the blades?
Generally with well designed blades fewer is better (yet balance to reduce stresses has led to many having 3). I don't think there is anything that says a turbine could not have more blades only that more have not proven better, yet.
what are the risk factor if i placed a turbine on building
Very good presentation. Thanks to Nebraska.
Very Good Explanation.
How to calculate the stresses applied (wind and gravity) to the blade/hub connection?
Sorry, I can't help with this
run on FEA
Why savonious are designed vertical instead of horizontal?
Because the winds blows horizontal and not vertical
The derivation at 2:01 should use lowercase "v" for mass flow rate... it is conflated with volume which makes it confusing when it's plugged in to solve for kinetic energy,
Thanks for your comment. Good observation, thanks
at 15:31 when the direction of wind changes how do you move the trubine ?
do you use a motor to move this or is there a better way to do it?
My guess is that the turbine has a tail, like most others. However, the picture, is such that it's hard to recognize the tail. I think the orientation of the turbine, makes the tail more difficult to see.
Doesn't the wing speed of turbine matter?
Yes the blade speed does matter. The revolutions per minute of large wind turbines will vary by design. Many turbine designs maintain a constant RPM to synchronize with the grid. The speed of the blade tip does matter as higher tip speeds generally results in higher efficiency. Small wind turbines generally spin faster at higher wind speeds and take the "wild" electricity and "clean" using power electronics.
Who taught this video? I would like to reach out to him by email?
5:12 what is TIP? Tips money for kelner? blade?
The small end of the wind turbine blade is the "tip"
A very helpful video. Thanks a lot.
good explanation, thanks
watch out: dm/dt = rho * A * v (velocity) NOT V (Volume)
Yay somebody telling it like it is.
perfect
So all those small turbines they are trying to sell, doesn't do much. The cost to install it with its own AC generator and inverter , and a battery for storage, isn't justifiable.
The economics of small wind turbines is poor. High cost of turbines, repair and maintenance. Payback longer than useful life is what I would expect. Yet there are applications where they may be useful. An offgrid home charging batteries might benefit from a combination of wind and solar. If you are off grid economics might be less important.
I have a question,
Why is there 1/2 in the equation ?
Because power is equal to energy per unit of time. And the energy in this case is the kinetic energy of the wind (1/2*m*v²).
Excellent description of Air as Kinetic wind energy as Force from an actual Mass and it`s Acceleration. KE = 1/2 M x V squared. I think of it sometimes that we are fishing in a great ocean of air, catching and releasing billions of molecular fish with a large Rotor Blade Net. No bloodletting, no pain, Clean.
Fantastic presentation!
please post some wind energy conversion system solved problem
Try: GMRT Wind turbine, Gelibolu, TUBITAK
Good explanation
Anybody can calculate how much watt i can get with in one hour?
Blade height 6mt, blade with 1m, distance from blade to blade 12mt, total blade count 10. wind speed avg. 10 m/s and r/p/m is 60.
Thanks.
The actual energy production of your turbine needs to be measured. Yet we can make some simple calculations.
Wind turbine with Diameter of 12 meters. Wind speed of 10m/s and 60 RPM
The power in the wind available to the turbine is about 56,500 Watts or 56.5 kW. This is a small turbine and efficiency is likely only moderate considering a tip speed ratio of ~3/1. With a 20% efficiency this turbine would generate 14 kWh in one hour of operation. In reality I would expect less since your high blade count adds to the solidity of the turbine giving you torque lower speed (rpm). Higher tip speeds lead to higher efficiency for electric generating turbines. Fewer blades will require higher wind speed to start low wind speed are low power so it doesn't matter much.
@@CropWatchBioenergy Thanks.
13:48 "Shrouded Turbines" are probably an extension of "Ducted Fans"
Nice work thanks
You don't give any formula that shows the relation of high wind speed on the design of the turbine. It's not that I don't believe you but just the same. Thank you for this very informative video.
Glad you liked it. I intentionally kept this simple. Wind turbines will gradually become less efficient as wind speed increases in order to maintain their RPM and at high wind speed may even shut off to protect themselves.
The answer to wind turbines is that they are now unnecessary. We now have the ultimate and cheapest green power device with none of these problems, in the SAFIRE GENERATOR. This is what we need to negate all the problems of all competing green energies. It produces almost costless electricity and therefore hydrogen from new FUSION NUCLEAR and is now immediately upon us. We have recently taken a new step to advance the physic of medium temperature plasma fusion power production by enabling chemistry of the atomic nucleus, or "nuchemy" in the newest FUSION NUCLEAR POWER technology. We are passing the chemistry level where we interacted with the atomic electron shells and are moving on to manipulations in this "NUCHEMY" atomic nuclear era when we interact and multiply nuclear protons. We have rediscovered the lost work of the alchemists and can make new elements with different atomic weights. This was ably demonstrated in "THE SAFIRE PROJECT". Quanta are important. We now have enough energy to manipulate the atomic nucleus much more easily by creating a compartment, or what is a local region of plasma containment so reactions at this atomic nuclear level can easily take place. This is about to practically enabled a really fantastic and cheap new era of energy production for the whole of mankind. This with hydrogen, so free fuel obtained from water or atmospheric moisture anywhere in the world. This new fusion nuclear SAFIRE GENERATOR is at the industrial commercial production final development point as of now and it can retrofit older and decommissioned power plants. The energy argument and other power methodologies are all now virtually irrelevant as we have new and very physically and economically powered practical and local community level fusion nuclear power. Solar roof plus Teslawall battery may be the present way to go domestically but megapack batteries and multiple storage technologies interconnected with an expanded ugly grid have a less certain requirement when you consider new any-scale community based and 24 hr reliable and self-fueling fusion nuclear in the form of the "SAFIRE REACTOR". Learn all about it at "AUREON @t". Then learn the newer EU Theory and plasma physics at "THUNDERBOLTS @t" and you will be permanently reeducated with this advanced newer EU theory that will allow you to understand more about the astrophysics of our whole universe and all within and you will be more informed and can teach your peers.
Betz law is so simple to beat I am surprised that it is a law at all regards Graham
Hi Sir, this is a wind energy problem "Given a wind speed of 8𝑚 𝑠 and a blade tip speed ratio of 3. Calculate the blade chord angle at radius ratios 𝑅′ of 0.2, 0.6 & 1 for 1.An angle of attack of 0degree.2. An angle of attack of 16degrees." I would be grateful if u could help me out by solving this problem as I didn't understand this problem but found it similar to your videos
Apparently you have had to do your own homework!
@@SeattlePioneer yep and i have graduated haha
@@Fedroy90 >
Congratulations! I'd be glad to hear what that has meant for you.
EXCELENTE EXPLICACION.
Thank you, very helpful video sir.
The model is fully available on redslibrary website
How to calculate small wind produced
3 KW Please?
You can use the formula for power in the wind and solve for rotar diameter based on a given wind speed.
3kw is going to be in the 15 to 20 ft dia range at low wind speeds.
I like your explanation but i belive in vertical wind turbine. because take less space.
very good thank you
The size of the blades are pretty much at there max. Developers need to create turbines that can float on the ocean.
Betz affects only HAWTs. For VAWTs it has to be redefined.
Greattt
Before you mention carbon dioxide in air you should mention argon 0.9% and water vapor 1% , 25x more than carbon dioxide 0.038%
Not relevant. He simply gave examples and you'll be calculating based on overall air density anyway
@@jamesengland7461 .. exactly, not at all relevant to mention CO2.
@@johnq8792 your nitpicking is pointless. Have a nice day
@@jamesengland7461 ... your nitpicking is pointless, have a nice day :)
SUPERB
Really Helpful ..
Thx too much ..
thanksអគុណបង
...probably the savonius turbine could be more efficient if it has improved rotor profile
air synergy etc make more power in low winds
bahrain world trade center twin tower has wind turbines on their building and produces 10-15% of the entire twin tower electricity
I would be interested to see the real data. I am skeptical about the actual production vs estimated. I would expect they produce much less than expected.
detailed!
Thank you, awesome