A couple of disadvantages you didn't mention: taking kinetic energy out of the river can result in unwanted sedimentation and/or change the ecology. And dams may need some way for salmon to get upstream of them.
These hydro dams have environmental effects, sure. I wouldn't say destruction as much as i would say change. Is a lake full of water that gets refreshed seasonally less environmentally friendly than a gorge? There is one nearby and it's great for recreation and fishing.
thisisn'tmyrealname it’s disruptive enough to actually cause huge short term damages but as you mentioned would eventually recover, most of the concerns revolve around relocations of human capital otherwhere and then the local damage it will cause environmentally
If we were more creative we would learn that water, does not have to leave the dam! All the pressure we need is at the bottom inside the dam. "Imagination is more powerful than an education"
I like the idea of small-scale hydropower, except for one thing: It doesn't provide any reserve power that you can tap into when other energy sources are running short. OTOH big dams do.
That depends entirely on the particular water flow you're talking about. There are streams fed from springs which are not seasonal. These tend to be small, but then that's exactly what the video is about. Other streams vary massively by season, but you could still make stable power if you based your flow on the lower end of the spectrum and then just bypassed the excess.
06:55 They don't even put metric on the measuring tapes? In Canada, the tapes have both imperial and metric on the tapes, at least all the ones I've owned.
SI meter tapes are available but hardly anybody buys them, just no need. I own a few mixed unit tapes,(SI, fractional inch, decimal inch, decimal feet) but I find they are really only good for occasional use, its much easier to convert numerically if needed. Any professional user finds mixed unit tapes problematic because they very rarely need to switch scales (all their materials are standardized) and the scale you need ends up on the wrong side half of the time, which is an issue when making measures and marks with any real precision.
I've started linking to this channel to help show climate alarmists/cultists what the difference between actual reality and whatever fantasy world they live in is. WOW, do they hate this guy and yet they can't actually say where he is wrong on anything!
Many of the old low head dams could/should be redeveloped given much study has shown that such structures tended to provide more long term environmental/ecological good in their locations than they do negatives in the short term as they establish their local ecological balance points.
Efficiency is 0.6…Are underwater turbines governed by Betz's Law in the same way that wind turbines are? I would expect so, as I don't remember its calculation depending on air density.
Why is high pressure better for efficiency. Maybe because you have to get over the minimum requirement to go against the air/wind and friction but that doesn't seem like much.
Higher head is considered higher quality power. This derives from general thermodynamics laws and entropy, a higher energy gradient always has a higher potential efficiency. I won't try to explain such thermodynamics here, for that you need a proper instructor. In heat engines a higher temperature difference is also more efficient, in kinetic systems higher differences in speed, electricity higher a voltage differential. Consider that steam engines operating on fire are very useful, but there are no practical heat engines that work off of the temperature gradients of ocean currents even though such ocean thermal energy is far greater than all fossil fuel use, the thermal gradient is just too small to efficiently convert into a useful form.
Volume, density and velocity tells you the "feed rate" of the water wheel. How much potential energy, per unit of time is going through the dam. For example 10 cubic meters per second. You need gravity and the height of the dam to calculate how that potential energy will be transformed into energy. You could have one dam that is only 10 meters high and another that is 50 meters high. The higher the dam the more gravitational force to turn the wheels faster or with more torque.
I think you are alluding to the kinetic energy of the water. However, that kinetic energy is the result of gravity and height just a bit upstream, energy is force times distance in this case weight times height. The kinetic energy of the free flowing stream is really not very useful and usually pretty small compared to gravitational potential energy, and kinetic can only be partially reduced; if you bring it to a full stop where do you put the next unit of water, and the next.
Really you need to consider that you measured the water velocity in the center where you have higher velocity turbulent flow. As you get closer to the sides and the bottom the flow is more laminar and slower. Just a rough guess, but I'll bet you'd need to cut your water volume/time figures by 50% Not wanting to bust anyone's bubble, but currently there are very overly optimistic perceptions of renewable energy by the general public and it's leading to bad policy, poor decisions and wasted resources.
@@drewgehringer7813 Look closely. He's writing on a sheet of glass that's in front of him, not a mirror. Go fog a window and try to read what you write from the other side. You can't unless you write it backwards.
![เปิด อาณาจักร หมื่นล้าน "สาระตั้ม" l [Nickynachat]](http://i.ytimg.com/vi/3XE0nPF4YkQ/mqdefault.jpg)
Great educator. Practical lessons
A Gentleman and a Scholar is showing us that mechanics need NOT be difficult. I thank you Sir!
I love how hands on this lesson is, really wish more teachers would be like this
You're like one of those professors in cinema - always interesting and dramatic. Second point: those are very nice rocks in that rock wall.
You are a very interesting man
Great class! Nothing like a practical example.
Beautiful way of teaching!
Fantastic teacher !!!
You're really awesome professor. I wish I had professor like you when I studied engineering
What a teacher my goodness!!!
I never had him at Illinois and I regret it! I did have my fair share of cool profs though, Stelzer and Kudeki were two of my favorites.
great info .now we need a talk on reaction turbines vers Impuls turbines. well done thanks for sharing.
I like this professor! nice job.
awesome video i wish i was there!
10:10 - I liked to do this kind of stuff when I was a kid.
nice. the MATH is what I need.
2:31 like a true engineer
i really like the plot twist at 18:53
A couple of disadvantages you didn't mention: taking kinetic energy out of the river can result in unwanted sedimentation and/or change the ecology.
And dams may need some way for salmon to get upstream of them.
I kept waiting for that to be discussed
I think he should have been doing a wind energy video during this half hour. ;)
These hydro dams have environmental effects, sure. I wouldn't say destruction as much as i would say change. Is a lake full of water that gets refreshed seasonally less environmentally friendly than a gorge? There is one nearby and it's great for recreation and fishing.
thisisn'tmyrealname it’s disruptive enough to actually cause huge short term damages but as you mentioned would eventually recover, most of the concerns revolve around relocations of human capital otherwhere and then the local damage it will cause environmentally
The problem is that you can use that argument for really any type of ecological change
metric for the win
If we were more creative we would learn that water, does not have to leave the dam! All the pressure we need is at the bottom inside the dam. "Imagination is more powerful than an education"
I like the idea of small-scale hydropower, except for one thing: It doesn't provide any reserve power that you can tap into when other energy sources are running short. OTOH big dams do.
That depends entirely on the particular water flow you're talking about. There are streams fed from springs which are not seasonal. These tend to be small, but then that's exactly what the video is about. Other streams vary massively by season, but you could still make stable power if you based your flow on the lower end of the spectrum and then just bypassed the excess.
06:55 They don't even put metric on the measuring tapes? In Canada, the tapes have both imperial and metric on the tapes, at least all the ones I've owned.
SI meter tapes are available but hardly anybody buys them, just no need. I own a few mixed unit tapes,(SI, fractional inch, decimal inch, decimal feet) but I find they are really only good for occasional use, its much easier to convert numerically if needed. Any professional user finds mixed unit tapes problematic because they very rarely need to switch scales (all their materials are standardized) and the scale you need ends up on the wrong side half of the time, which is an issue when making measures and marks with any real precision.
Someone get the man a tape measure with imperial and metric.... lol
would be nice to add a small tube to the plywood with tiny turbine and some leds for full effect ...
That land might be used for something else, like your neighbor's house. Awesome.
You are awsome 👍
I've started linking to this channel to help show climate alarmists/cultists what the difference between actual reality and whatever fantasy world they live in is. WOW, do they hate this guy and yet they can't actually say where he is wrong on anything!
The Auburn Dam Site in Northern California could be developed.
Many of the old low head dams could/should be redeveloped given much study has shown that such structures tended to provide more long term environmental/ecological good in their locations than they do negatives in the short term as they establish their local ecological balance points.
good luck battling the environmentalists.
For those who were disappointed that no real turbans were shown, Sikh and ye shall find.
Efficiency is 0.6…Are underwater turbines governed by Betz's Law in the same way that wind turbines are? I would expect so, as I don't remember its calculation depending on air density.
The kinematic viscosity of air is higher than water, so water may be somewhat more efficient. I haven't run the numbers though.
Why is high pressure better for efficiency. Maybe because you have to get over the minimum requirement to go against the air/wind and friction but that doesn't seem like much.
The more pressure, the faster the weel spins, the more efficient are the 'dynamos' attached to it
Higher head is considered higher quality power. This derives from general thermodynamics laws and entropy, a higher energy gradient always has a higher potential efficiency. I won't try to explain such thermodynamics here, for that you need a proper instructor.
In heat engines a higher temperature difference is also more efficient, in kinetic systems higher differences in speed, electricity higher a voltage differential. Consider that steam engines operating on fire are very useful, but there are no practical heat engines that work off of the temperature gradients of ocean currents even though such ocean thermal energy is far greater than all fossil fuel use, the thermal gradient is just too small to efficiently convert into a useful form.
me after years of studying: g is 9,81m/s²
Energyprof: g is 10 , close enough
If you have volume density and velocity I don't understand why you need gravity or height of the dam.
Volume, density and velocity tells you the "feed rate" of the water wheel. How much potential energy, per unit of time is going through the dam. For example 10 cubic meters per second.
You need gravity and the height of the dam to calculate how that potential energy will be transformed into energy.
You could have one dam that is only 10 meters high and another that is 50 meters high.
The higher the dam the more gravitational force to turn the wheels faster or with more torque.
I think you are alluding to the kinetic energy of the water. However, that kinetic energy is the result of gravity and height just a bit upstream, energy is force times distance in this case weight times height. The kinetic energy of the free flowing stream is really not very useful and usually pretty small compared to gravitational potential energy, and kinetic can only be partially reduced; if you bring it to a full stop where do you put the next unit of water, and the next.
6:15 David The Baptist.
Thôsé Dâm Boooooooooooo-Eaze
untt
Turbãns 👳
Really you need to consider that you measured the water velocity in the center where you have higher velocity turbulent flow. As you get closer to the sides and the bottom the flow is more laminar and slower. Just a rough guess, but I'll bet you'd need to cut your water volume/time figures by 50%
Not wanting to bust anyone's bubble, but currently there are very overly optimistic perceptions of renewable energy by the general public and it's leading to bad policy, poor decisions and wasted resources.
Dear god hes gone mobile…
Am I the only one baffled by his ability to write backwards?
The video's been mirrored
@@drewgehringer7813 Look closely. He's writing on a sheet of glass that's in front of him, not a mirror. Go fog a window and try to read what you write from the other side. You can't unless you write it backwards.
@@jamesmatthew1903 The video is flipped in the video editor.
@@timc7035 If the flipped version show words in the correct direction that would mean he's writing backwards.
Dude. Are you serious? you think he is a leftie? look at his ring finger? what hand is a wedding ring on? the video is mirrored. Stop trolling.