Post by Deleted on Dec 19, 2016 3:38:05 GMT
There's a constant undercurrent of proposals to use waves as a large power source, usually to make electricity. Waves have been used to make electricity, and without a doubt the installations were very pricey. And the power delivered was periodic.
But people do not seem to understand waves themselves. What you see on the surface is water pushed up by a pressure wave below. What's mildly interesting is you can make a wave by actually making a wave (which makes a pressure wave below because it's a taller section of water which exerts pressure at it's base), or you can make an internal pressure wave (which then squeezes up some water above mean water level). It's that internal pressure wave which keeps on propagating thru the pool.
Nearly all wave machines are easily broken by the waves they are designed for. The priciest failure was the Sea Snake . In Vancouver there was another multi$million failure using vertical generators, one of which was installed.
I promise i will not throw math at you in this post. I will be general, display common sense, and if you are interested, you should do your additional research elsewhere.
But about waves.... They are physical manifestations you can see, they are molecules moving, they transport power. They can be made several ways: generate a pressure change (which you cannot see) within the water (ocean floor geologic shifts make tsunamis), blow air across the surface (hurricanes make waves), physically displace the water at the surface (drop something into it, like a meteor, the top of a volcano, a cliff face, or a pebble), or move a section of the water (wave study tanks use hinged baffles driven by motors, hydraulics, or engines). Once made, i don't give a rats ass how it was made, and debating the origins of a series of waves is most likely pointless. {{ Gotchas include knowing where the wave came from, and tsunami are generally one shelf wave vs a train of recurring waves. }} The wave is an internal water pressure animal, and since water is basically incompressable, some of it is squeezed upwards where the pressure is highest, and the surface is sucked down in the low pressure sections. This is how some ocean floor wave gauges function: they measure the water pressure. If the high pressure areas of the wave train are far enough apart, we call the rising water "swells", it's a long-wavelength wave by another name, you know, like how "genuine Faux diamonds" are still fakes?
Ok, from now on i am talking ONLY about deep water waves, not beach crashing waves. Crashing waves are too tall to hold themselves up, and beach bottoms slow the bottom of the pressure wave, so the normal wave trips and falls on it's face.
Mind what i said about "squeezed upwards where the pressure is highest". The water is moving *upwards* to form a peak. The water isn't a curved lens sliding across the surface. A wave approaching the boat is not approaching the boat. The pressure wave inside the water is only wanting to keep on moving under the boat, it is pushing the water up as it goes under the boat, and if the boat doesn't move up as the water would, the water that can move just rises up against the side of the immoveable boat. And the boat is pushed up. So why do waves contacting boats throw so much spray? Because the boat is displacing the water, it's redirecting the pressure wave, the boat is moving, and the boat's shape is to get thru the water by relocating the water.
So how do you get energy out of the wave?
Most try to get some part of a contraption to get moved by the moving water. In the open ocean, this would be up and down. Various mechanical link types can redirect the motion, and increase or decrease the stroke of peak-to-trough-to-peak movement. The two most common things people try to get moving is a metal arm with a floating air tank on the end, or a volume of air in a tank that's open to the internal pressure wave (tho not necessarily to the water being squeezed up - the wave).
There's also the paddle approach that moves under the surface of the water, reacting to the pressure wave directly (but can respond to only one direction of wave travel, and often is pushing water the pressure wave wasn't going to). And the water-tank-overtopping which pretends to be a land-based hydropower system (but in the ocean with almost no useable water depth over the turbine).
So far, from all i have read (and i was reading of this stuff in Science mag in the early 1970's, and i go boating), the most efficient, and coincidently lowest cost, is a loose grid structure that floats on or hangs down under, umm, floaties, and any wave at any point is free to move a floatie up or down as much and whenever it wants to. The floatie pulls or pushes against it's connecting grid, meaning it is acting against the mean of all the other floaties, and so does not need to be fastened firmly to anything. The best of the grid-connected systems of this type that i am aware of act as hydraulic pumps, using desalinated water as a medium, to operate a generator on a nearby shore. It's lightweight, and well designed, it was deployed by a few guys in rowboats. Arbitrary sections can be added or removed whenever.
The worst systems which have been built and tested have been paddle and overtopping schemes. The initial cost and maintenance have been highest, and the quantity of power delivered had made them not worth it at all.
Sometimes, you must *understand* what's being said is marketting hype, for instance:
This makes me wonder when Hawaii was transported to North America, because last time i checked it was a set of mid-ocean volcanic islands, and not anywhere near the North American continental shelf.
Encyclopedias and other databases aren't regularly updated, and there's rules about what can be said before it's questioned as slander. However, several companies that are mentioned in Wikipedia as active players in the wave power dept no longer exist, or no longer play in the water.
Seems like an hour ago, i said in this post that waves are physical things. They obey the laws of fluid physics. Your device to convert the motion of the waves into some other form of energy must operate under those same laws. And it must be economical, be buildable, and must survive in the ocean waters.
Good luck.
But people do not seem to understand waves themselves. What you see on the surface is water pushed up by a pressure wave below. What's mildly interesting is you can make a wave by actually making a wave (which makes a pressure wave below because it's a taller section of water which exerts pressure at it's base), or you can make an internal pressure wave (which then squeezes up some water above mean water level). It's that internal pressure wave which keeps on propagating thru the pool.
Nearly all wave machines are easily broken by the waves they are designed for. The priciest failure was the Sea Snake . In Vancouver there was another multi$million failure using vertical generators, one of which was installed.
I promise i will not throw math at you in this post. I will be general, display common sense, and if you are interested, you should do your additional research elsewhere.
But about waves.... They are physical manifestations you can see, they are molecules moving, they transport power. They can be made several ways: generate a pressure change (which you cannot see) within the water (ocean floor geologic shifts make tsunamis), blow air across the surface (hurricanes make waves), physically displace the water at the surface (drop something into it, like a meteor, the top of a volcano, a cliff face, or a pebble), or move a section of the water (wave study tanks use hinged baffles driven by motors, hydraulics, or engines). Once made, i don't give a rats ass how it was made, and debating the origins of a series of waves is most likely pointless. {{ Gotchas include knowing where the wave came from, and tsunami are generally one shelf wave vs a train of recurring waves. }} The wave is an internal water pressure animal, and since water is basically incompressable, some of it is squeezed upwards where the pressure is highest, and the surface is sucked down in the low pressure sections. This is how some ocean floor wave gauges function: they measure the water pressure. If the high pressure areas of the wave train are far enough apart, we call the rising water "swells", it's a long-wavelength wave by another name, you know, like how "genuine Faux diamonds" are still fakes?
Ok, from now on i am talking ONLY about deep water waves, not beach crashing waves. Crashing waves are too tall to hold themselves up, and beach bottoms slow the bottom of the pressure wave, so the normal wave trips and falls on it's face.
Mind what i said about "squeezed upwards where the pressure is highest". The water is moving *upwards* to form a peak. The water isn't a curved lens sliding across the surface. A wave approaching the boat is not approaching the boat. The pressure wave inside the water is only wanting to keep on moving under the boat, it is pushing the water up as it goes under the boat, and if the boat doesn't move up as the water would, the water that can move just rises up against the side of the immoveable boat. And the boat is pushed up. So why do waves contacting boats throw so much spray? Because the boat is displacing the water, it's redirecting the pressure wave, the boat is moving, and the boat's shape is to get thru the water by relocating the water.
So how do you get energy out of the wave?
Most try to get some part of a contraption to get moved by the moving water. In the open ocean, this would be up and down. Various mechanical link types can redirect the motion, and increase or decrease the stroke of peak-to-trough-to-peak movement. The two most common things people try to get moving is a metal arm with a floating air tank on the end, or a volume of air in a tank that's open to the internal pressure wave (tho not necessarily to the water being squeezed up - the wave).
There's also the paddle approach that moves under the surface of the water, reacting to the pressure wave directly (but can respond to only one direction of wave travel, and often is pushing water the pressure wave wasn't going to). And the water-tank-overtopping which pretends to be a land-based hydropower system (but in the ocean with almost no useable water depth over the turbine).
So far, from all i have read (and i was reading of this stuff in Science mag in the early 1970's, and i go boating), the most efficient, and coincidently lowest cost, is a loose grid structure that floats on or hangs down under, umm, floaties, and any wave at any point is free to move a floatie up or down as much and whenever it wants to. The floatie pulls or pushes against it's connecting grid, meaning it is acting against the mean of all the other floaties, and so does not need to be fastened firmly to anything. The best of the grid-connected systems of this type that i am aware of act as hydraulic pumps, using desalinated water as a medium, to operate a generator on a nearby shore. It's lightweight, and well designed, it was deployed by a few guys in rowboats. Arbitrary sections can be added or removed whenever.
The worst systems which have been built and tested have been paddle and overtopping schemes. The initial cost and maintenance have been highest, and the quantity of power delivered had made them not worth it at all.
Sometimes, you must *understand* what's being said is marketting hype, for instance:
Azura is a wave power device currently being tested in Hawaii. It is connected to the municipal grid providing electricity to Hawaii. According to the United States Department of Energy, this is the first time that a wave power generator has been officially verified to be supplying energy to a power grid in North America.
Encyclopedias and other databases aren't regularly updated, and there's rules about what can be said before it's questioned as slander. However, several companies that are mentioned in Wikipedia as active players in the wave power dept no longer exist, or no longer play in the water.
Seems like an hour ago, i said in this post that waves are physical things. They obey the laws of fluid physics. Your device to convert the motion of the waves into some other form of energy must operate under those same laws. And it must be economical, be buildable, and must survive in the ocean waters.
Good luck.