Reef Central Online Community

Home Forum Here you can view your subscribed threads, work with private messages and edit your profile and preferences View New Posts View Today's Posts

Find other members Frequently Asked Questions Search Reefkeeping ...an online magazine for marine aquarists Support our sponsors and mention Reef Central

Go Back   Reef Central Online Community Archives > General Interest Forums > Responsible Reefkeeping

 
 
Thread Tools Search this Thread Display Modes
  #1  
Old 11/17/2007, 12:11 PM
phish guy phish guy is offline
Registered Member
 
Join Date: Oct 2007
Location: southern NJ
Posts: 80
hydro powering our tanks

i was just thinking the other day, why dont we incorperate hydro power generators into tanks, ecspecially larger systems. i mean with all the water flow we encorperate through filters, isnt there a way to harness the power? just simple wheel on the inlet would spin like a turbine in a dam and generate power.

now im no electrican but wouldnt it work? i mean i dont think we could power our houses or anything but couldnt it at least power our tanks, or at least cut the cost of powering our tanks?

just some thoughts. anyone think it would work?
__________________
set your imagination aflight
  #2  
Old 11/17/2007, 12:15 PM
ahoyhoy239 ahoyhoy239 is offline
Registered Member
 
Join Date: Feb 2007
Location: Miami, FL
Posts: 198
Send a message via AIM to ahoyhoy239
you wouldnt be able to have the tank power itself but you could probably power like a fuge light and small things like that, so yes it would work to some extent
  #3  
Old 11/17/2007, 01:02 PM
iCam iCam is offline
Comme un soleil ensorcelé
 
Join Date: Feb 2003
Location: College Station,Tx
Posts: 3,969
Send a message via AIM to iCam
I might just put a dam in mine.
  #4  
Old 11/18/2007, 06:46 PM
mscarpena mscarpena is offline
Registered Member
 
Join Date: Jun 2004
Location: new york
Posts: 40
I was thinking of trying to build some small turbines to power my house with wind power. It can not be that hard right??
  #5  
Old 11/19/2007, 10:10 AM
greenbean36191 greenbean36191 is offline
Soul of a Sailor
 
Join Date: Jun 2003
Location: Huntsville/ Auburn, AL
Posts: 7,859
Send a message via AIM to greenbean36191
There is no free lunch. You could install a turbine and get energy back from it, but there's no such thing as 100% efficiency. You would be taking electrical energy, converting it to mechanical, then back to electrical (and then presumably either to mechanical or light) with losses at each step. You get back a lot less energy than you put in. The turbine would decrease the flow, so in order to get the same amount of flow you originally had, you would have to increase the wattage of the pump by more than the wattage put out by the turbine. If the lower flow doesn't bother you then it would still cost less to just run a smaller pump than it would to run the current pump, with the energy reclaimed by a turbine.
__________________
Lanikai, kahakai nani, aloha no au ia 'oe. A hui hou kakou.
  #6  
Old 12/02/2007, 08:47 AM
samtheman samtheman is offline
Registered Member
 
Join Date: Nov 2005
Posts: 483
Are physics classes still required in High School?
  #7  
Old 01/08/2008, 11:15 PM
TheFishGuy,LLC TheFishGuy,LLC is offline
Registered Member
 
Join Date: Jan 2008
Location: Jonesboro, AR
Posts: 7
Send a message via Yahoo to TheFishGuy,LLC
Nope, and they've made college physics easier.
  #8  
Old 01/08/2008, 11:35 PM
old salty old salty is offline
Mortar Target
 
Join Date: Jun 2005
Location: The Island of Misfit Toys
Posts: 2,870
This is also being touted as "Progress".
__________________
The irony of 2007 is a disgustingly fat multi-millionaire trying to tell me I need to cut back on my consumption.
  #9  
Old 01/09/2008, 12:55 AM
ozyreefa ozyreefa is offline
Registered Member
 
Join Date: Dec 2007
Location: Queensland, Australia
Posts: 71
Quote
The turbine would decrease the flow, so in order to get the same amount of flow you originally had, you would have to increase the wattage of the pump by more than the wattage put out by the turbine.


This is not entirely correct. Putting a turbine into, say, the pipe that heads towards the sump in a bulkhead overflow setup, will not require a bigger pump, but a larger over flow. There is absolutlely no resistance put on the return pump by putting anything into the overflow (unless your entire display and sump are completely airtight, which of course, they are not), however it will take more water above your overflow level to balance out resistance in the pipe from the turbine( higher water level means increased pressure into the overflow pipe itself).
__________________
umm like fish an stuff
  #10  
Old 01/09/2008, 01:35 AM
kaptken kaptken is offline
Registered Member
 
Join Date: May 2003
Location: New castle, De.
Posts: 1,214
Well GB, there certainly is no free lunch when energy recovery is concerned, but there is subsidized. We could recoup some of the energy expended in raising water from sump to tank and falling back again. It seems to me we did a thread like this a couple years back on the large reef tank forum?

Regular, sealed tight clearance turbines would be a very bad choice for many reasons. First they need a lot of flow with a very large head of water and no bypass. that would be bad when the impeller shaft gunks up with calcium and holds up the impeller. back up and overflow the tank.

My best suggestion would be to build a 3 foot diameter acrylic bucket wheel, like an old colonial overflow gris mill water wheel, supplied by the tank overflow return to the sump. enclose it in a gasketed acrylic box with lots of room for the water to overflow should its shaft get impacted with calcite. the large diameter wheel would provide low speed torque to drive an external pulley and belt system geared to turn a DC generator. and preclude tank overflows. The DC power could be conditioned with an inverter to run a pump or powerhead. or heater. recapturing some of the spent watts by gravity.

But a much simpler app would be to install a few 1 1/2 volt solar cells in the light hood to collect reflected light, and run the hood DC computer type exhaust fans. Lights on... fans on.. no need for extra power cord, transformer, and timer.
__________________
Bend To Fit...Paint To Match...Kick To Start.
  #11  
Old 01/09/2008, 06:05 AM
ozyreefa ozyreefa is offline
Registered Member
 
Join Date: Dec 2007
Location: Queensland, Australia
Posts: 71
Quote
"But a much simpler app would be to install a few 1 1/2 volt solar cells in the light hood to collect reflected light, and run the hood DC computer type exhaust fans. Lights on... fans on.. no need for extra power cord, transformer, and timer."



This is such a ridiculously good idea that I cannot believe hood manufacturers havent already incorporated this design already, you take a look at almost any lighting fixture and i think it is fair to say that at bare minimum at least 10% of the light never reaches the tank, in some metal halide fixtures in can be much more than that though, so I think almost any tank is capable of reusing its dead loss of power. Im off to the electronics store to pick up some fans and solar panels, and im going to pick up a cheap dyno and have a play around with a few ideas towards hydro powered tanks. Should be some interesting results.
__________________
umm like fish an stuff
  #12  
Old 01/09/2008, 06:28 AM
samtheman samtheman is offline
Registered Member
 
Join Date: Nov 2005
Posts: 483
You will be wasting your money. But, your education will be useful to others, so post your results.
  #13  
Old 01/09/2008, 07:23 AM
ozyreefa ozyreefa is offline
Registered Member
 
Join Date: Dec 2007
Location: Queensland, Australia
Posts: 71
lol yeah i dont even need to cool my tank, it sits at 24.5C year round. Im just keen to see how much power can be generated from wasted light and falling water, i expect more power to come from the lights though!
__________________
umm like fish an stuff
  #14  
Old 01/09/2008, 10:49 AM
chrissreef chrissreef is offline
Registered Member
 
Join Date: Feb 2005
Location: Dallas
Posts: 513
there's a lot of ridiculously good ideas... the problem is they cost $ and "effort" that the opportunity cost of just screwing in a light bulb and burning electricity using old technologies outweigh the benefits to short term thinkers.

I believe there's a solar company out there that installs cells on peoples homes for free and either pays them for the electricity, or locks in their rate so it never ever increases - if there's extra power, they put it into the grid and sell it to other electricity providers. It's a great idea that's spreading slowly.

Another idea - which I really don't understand why everyone doesn't do this... is just install 1-2 small wind turbines on each home. They wont' power the home (like ovens, refridgerators, washers/dryers, aquariums) - but they'll certainly provide for LED/CF bulbs and small appliances like DVD players, cable boxes etc.
__________________
One's standard of living is definitively determined by the size of their reef. - me

We live with each other, not for ourselves - Protect our planet
  #15  
Old 01/09/2008, 01:42 PM
simmons797 simmons797 is offline
Registered Member
 
Join Date: Feb 2007
Location: Maryville, IL
Posts: 27
Quote:
Originally posted by ozyreefa
There is absolutlely no resistance put on the return pump by putting anything into the overflow , however it will take more water above your overflow level to balance out resistance in the pipe from the turbine
This sentence is a contradiction. How do you get more water above the overflow? By the pump pushing the water to higher level=more pressure head=pump working harder to produce the same flow (or bigger pump)=more electricity.

As an earlier posted put it "there is no free lunch".
  #16  
Old 01/10/2008, 12:18 AM
ozyreefa ozyreefa is offline
Registered Member
 
Join Date: Dec 2007
Location: Queensland, Australia
Posts: 71
I dont know where people are going wrong with this, if you have a bulkhead over flow, put something over it to partially block it, you will notice the water level in the sump drops a little and the level of water in the tank raises a little. Thats it.The only way it would create more head pressure is if you needed to make the return pipe taller, which you will not. I suppose alot has to do with where your return pipe enters the tank, but for the majority of us who have the return just below the surface of the water, the increase in head pressure would be fractional, particularly with returns that loop over the top of the tank.
__________________
umm like fish an stuff
  #17  
Old 01/10/2008, 07:27 AM
samtheman samtheman is offline
Registered Member
 
Join Date: Nov 2005
Posts: 483
Well, when do we see some actual trials?
  #18  
Old 01/10/2008, 02:14 PM
simmons797 simmons797 is offline
Registered Member
 
Join Date: Feb 2007
Location: Maryville, IL
Posts: 27
I don't want to start an argument but there flaws in your statement.

Quote:
Originally posted by ozyreefa
I dont know where people are going wrong with this, if you have a bulkhead over flow, put something over it to partially block it, you will notice the water level in the sump drops a little and the level of water in the tank raises a little.
Again, what causes the level in the tank to rise? An increase in pressure from the pump.


Quote:
Originally posted by ozyreefa
Thats it.The only way it would create more head pressure is if you needed to make the return pipe taller, which you will not.
Not true. The height of the return pipe is not the height you need to measure. The distance from the pump to where the water overflows is the distance relating to the pressure head. You have to think of the tank space between the pump outlet and the overflow as part of the "return pipe", otherwise you could just plumb your return through the bottom of the tank.


Quote:
Originally posted by ozyreefa
I suppose alot has to do with where your return pipe enters the tank, but for the majority of us who have the return just below the surface of the water,
You are correct it does matter where the return pipe enters but only in relation to where the overflow is. If your return pipe is above the overflow then it would not matter if the surface level rose (as long as it was still below the return), but you would already be using more energy to raise the water above the point where it is overflowing.


Quote:
Originally posted by ozyreefa
the increase in head pressure would be fractional, particularly with returns that loop over the top of the tank.
You are also corret that the increase would probably be fractional,
but any energy recovered would be an even smaller fraction. Thereby using more energy which is the exact opposite of what the original point of this thread was.

Last edited by simmons797; 01/10/2008 at 02:23 PM.
  #19  
Old 01/11/2008, 01:20 AM
kaptken kaptken is offline
Registered Member
 
Join Date: May 2003
Location: New castle, De.
Posts: 1,214
no, the water wheel wont back up the overflow. the open overflow falls to an open tray above the bucket wheel, fills the buckets as gravity does its work and pulls it down, rotating the wheel, then dumping it to an open bottom drain to the sump. zero back pressure. its an overshot water wheel. not a turbine that needs pressure and flow.
something midevil, like this
http://www.waterhistory.org/historie...aterwheel2.jpg
or this is better.
http://en.wikipedia.org/wiki/Image:O..._schematic.svg

simple , smooth, very efficient.
__________________
Bend To Fit...Paint To Match...Kick To Start.
  #20  
Old 01/11/2008, 07:45 AM
samtheman samtheman is offline
Registered Member
 
Join Date: Nov 2005
Posts: 483
You say very efficient. What do you mean? If this type of water wheel was efficient, it would be used in dams and other hydro generation. What type of generator are you going to run? You need 120 volt at 60 cycles.
  #21  
Old 01/11/2008, 03:09 PM
kaptken kaptken is offline
Registered Member
 
Join Date: May 2003
Location: New castle, De.
Posts: 1,214
you can build a simple overshot wheel with more than 70% efficiency.
http://www.hp-gramatke.net/pmm_physi...h/page0450.htm
like i said in my first post, we would not want a tight fitting turbine. they require a higher head of water and flow which means back pressure and would overflow the tank. and could sieze up.

generator and inverter also mentioned in my first post. its all there. build one if you can. a simple engineering lab experiment to account for bucket volume to handle the flow, lever arm length, and shaft power and speed and pulley ratios.
__________________
Bend To Fit...Paint To Match...Kick To Start.
  #22  
Old 01/11/2008, 04:03 PM
Buckeye ME Buckeye ME is offline
Always a Buckeye
 
Join Date: Mar 2005
Location: Evansville, IN
Posts: 793
If I had a large enough tank and a few more resources, I would be interested in trying something like that with a car alternator.

You can't expect to get a whole lot out of any setup like this, but it would still be cool to experiment.
__________________
"Nothing cleanses your soul like getting the hell kicked out of you." - Woody Hayes
 

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -5. The time now is 12:35 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Use of this web site is subject to the terms and conditions described in the user agreement.
Reef Central™ Reef Central, LLC. Copyright ©1999-2009