3/2 power law
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fresh water or salt water?
somebody going off the grid or just looking for backup power so as to post more?
gonna need a del operator for this job, el nino year? sand bags ready?
somebody going off the grid or just looking for backup power so as to post more?
gonna need a del operator for this job, el nino year? sand bags ready?
L´Andratté
Well-known member
Works also well in the Fetzer Valve ;D http://www.runoffgroove.com/fetzervalve.html.PRR said:
Probably an underrated genre...PRR said:
> fresh water or salt water?
The bear is white.
There are nearly no salt-water turbines. 99.99% of all the salt water on earth is all at the same level. There's a few large salt lakes, but they are salt because there's no handy place to run the water out.
The bear is white.
There are nearly no salt-water turbines. 99.99% of all the salt water on earth is all at the same level. There's a few large salt lakes, but they are salt because there's no handy place to run the water out.
PRR said:
I think there is some energy generation with salt water, I don't know where though... From the waves you could take some energy but not with turbines. Also with the tidal wave you could store the water at the high level and then let it go down by a turbine, and could generate when it's rising and with descendant as well. I don't know if this is being done but up to a few tens of meters between levels could be found in some places.
JS
Bay of fundy canada...joaquins said:
http://www.nrcan.gc.ca/energy/funding/current-funding-programs/cef/4955
JR
totoxraymond
Well-known member
We have some factories here in France. One is using tide to produce energy during rising and descendant movement.
Other turbines are using submarine current due to tides in french britain coasts.
Thomas.
Other turbines are using submarine current due to tides in french britain coasts.
Thomas.
hymentoptera
Well-known member
I don't really understand what he's saying, but I love the way it's written. I've read it 4 times now. 
> generation with salt water
You are correct; I am an idiot.
Around the corner from me is a tidal pond. At one time this WAS used to power a saw-mill.
There's a dam by the bay. At high tide the sea water fills the pond. At low tide they ran the pond out through a low-head water wheel, essentially a turbine such as Pop is describing. They could also catch a rising tide as the sea flowed into the pond. (However I think this one only used the out-flow, because there was also a small stream into the pond, and most of the year the out-flow was better than the in-flow, and reversing would be more work for little gain.)
Plans to tap tides go back well over 100 years. One fairly famous one off Cuba was torn-apart a long time ago. Bay of Fundy looks like good power (but if tide-mills get torn-up, this looks like a bad place). In Maine we have a squirrel-cage on the bottom of a nearby bay churning a few kilo-watts of experimental energy. It will have to be scaled-up a lot before it returns as much energy as it took to make it.
You are correct; I am an idiot.
Around the corner from me is a tidal pond. At one time this WAS used to power a saw-mill.
There's a dam by the bay. At high tide the sea water fills the pond. At low tide they ran the pond out through a low-head water wheel, essentially a turbine such as Pop is describing. They could also catch a rising tide as the sea flowed into the pond. (However I think this one only used the out-flow, because there was also a small stream into the pond, and most of the year the out-flow was better than the in-flow, and reversing would be more work for little gain.)
Plans to tap tides go back well over 100 years. One fairly famous one off Cuba was torn-apart a long time ago. Bay of Fundy looks like good power (but if tide-mills get torn-up, this looks like a bad place). In Maine we have a squirrel-cage on the bottom of a nearby bay churning a few kilo-watts of experimental energy. It will have to be scaled-up a lot before it returns as much energy as it took to make it.
Youngwhisk
Well-known member
PRR said:
With absolute respect sir. You are most certainly not an idiot!!!
if he is an idiot then that makes me an amoeba,
let's throw this into the mix>
"Osmotic power or salinity gradient power is the energy available from the difference in the salt concentration between seawater and river water. Two practical methods for this are reverse electrodialysis (RED) and pressure retarded osmosis (PRO). Both processes rely on osmosis with ion specific membranes. The key waste product is brackish water. This byproduct is the result of natural forces that are being harnessed: the flow of fresh water into seas that are made up of salt water.
In 1954 Pattle[1] suggested that there was an untapped source of power when a river mixes with the sea, in terms of the lost osmotic pressure, however it was not until the mid ‘70s where a practical method of exploiting it using selectively permeable membranes by Loeb [2] was outlined.
The method of generating power by pressure retarded osmosis was invented by Prof. Sidney Loeb in 1973 at the Ben-Gurion University of the Negev, Beersheba, Israel.[3] The idea came to Prof. Loeb, in part, as he observed the Jordan River flowing into the Dead Sea. He wanted to harvest the energy of mixing of the two aqueous solutions (the Jordan River being one and the Dead Sea being the other) that was going to waste in this natural mixing process.[4] In 1977 Prof. Loeb invented a method of producing power by a reverse electrodialysis heat engine.[5]
The technologies have been confirmed in laboratory conditions. They are being developed into commercial use in the Netherlands (RED) and Norway (PRO). The cost of the membrane has been an obstacle. A new, lower cost membrane, based on an electrically modified polyethylene plastic, made it fit for potential commercial use.[6] Other methods have been proposed and are currently under development. Among them, a method based on electric double-layer capacitor technology.[7] and a method based on vapor pressure difference.[8]
let's throw this into the mix>
"Osmotic power or salinity gradient power is the energy available from the difference in the salt concentration between seawater and river water. Two practical methods for this are reverse electrodialysis (RED) and pressure retarded osmosis (PRO). Both processes rely on osmosis with ion specific membranes. The key waste product is brackish water. This byproduct is the result of natural forces that are being harnessed: the flow of fresh water into seas that are made up of salt water.
In 1954 Pattle[1] suggested that there was an untapped source of power when a river mixes with the sea, in terms of the lost osmotic pressure, however it was not until the mid ‘70s where a practical method of exploiting it using selectively permeable membranes by Loeb [2] was outlined.
The method of generating power by pressure retarded osmosis was invented by Prof. Sidney Loeb in 1973 at the Ben-Gurion University of the Negev, Beersheba, Israel.[3] The idea came to Prof. Loeb, in part, as he observed the Jordan River flowing into the Dead Sea. He wanted to harvest the energy of mixing of the two aqueous solutions (the Jordan River being one and the Dead Sea being the other) that was going to waste in this natural mixing process.[4] In 1977 Prof. Loeb invented a method of producing power by a reverse electrodialysis heat engine.[5]
The technologies have been confirmed in laboratory conditions. They are being developed into commercial use in the Netherlands (RED) and Norway (PRO). The cost of the membrane has been an obstacle. A new, lower cost membrane, based on an electrically modified polyethylene plastic, made it fit for potential commercial use.[6] Other methods have been proposed and are currently under development. Among them, a method based on electric double-layer capacitor technology.[7] and a method based on vapor pressure difference.[8]
;D ;D PRR is not an idiot in any company....CJ said:if he is an idiot then that makes me an amoeba,
While perhaps valid, there so much power much easier to collect...
Tidal (gravity) energy is interesting but the vast majority of free energy (I don't like the term renewable, it all gets consumed) is from sun light heating the earth.
http://www.otecnews.org/what-is-otec/
I would place a string of these around the equator, a secondary benefit from cooling the equator surface is perhaps reducing the energy of tropical storms (guess?).
JR
JohnRoberts said:
The thing I like about that, it's one of the easiest to implement for private houses... Know a few people heating their water in that way, mirrors, black pipes and glass. There you have it, also very low mantainance so long term inversions throw quite better numbers than other alternatives. The problem is they aren't pretty and not every house can hide them, my cousin wanted to do so for his swimming pool, but he didn't have enough hidding roof to put them on so he didn't used it.
JS
> what-is-otec
Any scheme which needs three pumps just to get the concept over is too complicated to work.
Yes, I know a steam-plant is riddled with pumps, but a quick-draw only needs two, and you can cheat-away one of these and show the basic operation.
I also suspect that ammonia has come and gone, but I'm sure Dow can invent some new working fluids; they seem to have come up with a dozen new "freons" every year.
Any scheme which needs three pumps just to get the concept over is too complicated to work.
Yes, I know a steam-plant is riddled with pumps, but a quick-draw only needs two, and you can cheat-away one of these and show the basic operation.
I also suspect that ammonia has come and gone, but I'm sure Dow can invent some new working fluids; they seem to have come up with a dozen new "freons" every year.
That was just the first I found using google.. I think I have also seen these using a stirling cycle to extract power but I don't know how practical that is... If there is a hot end and a cold end they should be able to extract energy from that, and cool down the ocean surface at the same time.
None of these are practical while fossil energy is so cheap, but good to start thinking about this now so in a hundred years when we may need it hopefully the technology will be sorted. Expecting government to figure this out sounds a little scary.
JR
None of these are practical while fossil energy is so cheap, but good to start thinking about this now so in a hundred years when we may need it hopefully the technology will be sorted. Expecting government to figure this out sounds a little scary.
JR
> just the first I found
OK. Not doubting the general idea.
But looking again, I note they propose pumping-up from deep ocean. Have they ever tried this? It is hard work. To get a mild hose-flow at my house makes a 1/2HP motor work hard, and my well is only 90 feet. And the pump has to be at the bottom (can't suck-up more than 28 feet). The usual pumps run 60% efficiency (plus motor losses). Yes, if they return to the same depth "in theory" no work is required. But they do not show it that way; in a real design they would weigh the pumping costs against the cost of pipe.
Yes, in my swamp I can find 40 F water most of the year just 2 feet down, but 77 F water is scarce.
Stirling engines do run very well over some range of sizes. Toy Stirlings drag and leak. Mega-Stirlings are absurd monsters. Lot of machine for not a big power. An in-sea Stirling is amusing to think about: don't bring the water up, cycle the gas down. But the transfer duct has to be long, yet low-drag, and more insulated the deeper it needs to go.
Hot-air is available every 4 years, and a bumper-crop this year, but storage through off-years is awkward. (In general, good storage would lessen many everyday energy issues.)
OK. Not doubting the general idea.
But looking again, I note they propose pumping-up from deep ocean. Have they ever tried this? It is hard work. To get a mild hose-flow at my house makes a 1/2HP motor work hard, and my well is only 90 feet. And the pump has to be at the bottom (can't suck-up more than 28 feet). The usual pumps run 60% efficiency (plus motor losses). Yes, if they return to the same depth "in theory" no work is required. But they do not show it that way; in a real design they would weigh the pumping costs against the cost of pipe.
Yes, in my swamp I can find 40 F water most of the year just 2 feet down, but 77 F water is scarce.
Stirling engines do run very well over some range of sizes. Toy Stirlings drag and leak. Mega-Stirlings are absurd monsters. Lot of machine for not a big power. An in-sea Stirling is amusing to think about: don't bring the water up, cycle the gas down. But the transfer duct has to be long, yet low-drag, and more insulated the deeper it needs to go.
Hot-air is available every 4 years, and a bumper-crop this year, but storage through off-years is awkward. (In general, good storage would lessen many everyday energy issues.)
In fact good (better) insulation can still dramatically reduce energy waste for heating/cooling homes.
Now a few years into my personal experiments I am discovering secondary issues related to "tight" houses, like humidity. For winter use the de-humidifier is also a space heater. ;D
There is a lot of low hanging fruit (energy savings) and cheap energy sources before this becomes serious (like for the next ice age).
JR
Now a few years into my personal experiments I am discovering secondary issues related to "tight" houses, like humidity. For winter use the de-humidifier is also a space heater. ;D
There is a lot of low hanging fruit (energy savings) and cheap energy sources before this becomes serious (like for the next ice age).
JR
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