AuthorTopic: Small Dam & Micro-Hydro Building  (Read 11127 times)

Offline Farmer McGregor

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Re: Small Dam & Micro-Hydro Building
« Reply #105 on: March 06, 2017, 11:33:07 AM »
One of the marvelous things about electric motors is they work both ways.  If you put electricity in, the motor turns.  The other way, if you turn the motor, electricity comes out.
Yes, it is generally true that 'motors generate and generators motor'.  Not 100% always, though; depends on the design of the device.  But neither of them does a very good job when used this way unless they were designed to do so; efficiency goes down.  Ever tried to make an automotive alternator work as a motor, or a starter motor serve as a generator?  You might get some action, but not worth a shit in the long run.

Better to use generators, actually alternators, that are intended for the purpose.  Why go to all the trouble to channel water into a low efficiency device that will probably wear out prematurely from being improperly operated?  Or that can't take an occasional soaking.

Stick to your guns, Eddie.  Those devices you're proposing look like the cat's meow.
For years we have let ourselves believe that as long as we have money we will have food. This is a mistake. The government will bring forth no food by providing hundreds of billions of dollars to the agribusiness industry.  --Wendell Berry after the 2008 crash

Offline RE

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Re: Small Dam & Micro-Hydro Building
« Reply #106 on: March 06, 2017, 11:45:02 AM »
One of the marvelous things about electric motors is they work both ways.  If you put electricity in, the motor turns.  The other way, if you turn the motor, electricity comes out.
Yes, it is generally true that 'motors generate and generators motor'.  Not 100% always, though; depends on the design of the device.  But neither of them does a very good job when used this way unless they were designed to do so; efficiency goes down.  Ever tried to make an automotive alternator work as a motor, or a starter motor serve as a generator?  You might get some action, but not worth a shit in the long run.

Better to use generators, actually alternators, that are intended for the purpose.  Why go to all the trouble to channel water into a low efficiency device that will probably wear out prematurely from being improperly operated?  Or that can't take an occasional soaking.

Stick to your guns, Eddie.  Those devices you're proposing look like the cat's meow.

They work OK for the sailors.  Also, car alternators work both ways.  One way they crank the engine, the other way the engine cranks them and they recharge the battery.

But I will grant you that it is better to use a generator design for this than a motor design.  So substitute a generator design for the trolling motor if you want super efficiency.  However, you can buy the trolling motors off the shelf CHEAP at Sportsman's Warehouse.  I can probably buy 3 of them for every 1 specially designed generating motor and get twice the juice.

The bottom line here is that at shallow depth, these turbines can't possibly produce the same amount of power as a turbine 3 or 4 feet under water.  The pressure is so much greater it turns a bigger turbine.  That is straight physics.

RE
« Last Edit: March 06, 2017, 11:47:22 AM by RE »
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Offline Farmer McGregor

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Re: Small Dam & Micro-Hydro Building
« Reply #107 on: March 06, 2017, 11:58:19 AM »
...car alternators work both ways.  One way they crank the engine, the other way the engine cranks them and they recharge the battery.

RE
au contraire, mon frère! :D
Automotive alternators play absolutely no roll in turning the engine; they are strictly a motion input, not output, device.  And they don't motor worth a shit because of the way the field windings are constructed.  Horsepower output is very poor and they heat up quickly.  They do, however, make small motor/generators that are used on things like riding lawnmowers -- dual purpose devices that work as you describe.

As for "working okay for the sailors", yes, they can trickle charge their batteries this way.  Great dual purpose use for a trolling motor that you have on board anyway.
For years we have let ourselves believe that as long as we have money we will have food. This is a mistake. The government will bring forth no food by providing hundreds of billions of dollars to the agribusiness industry.  --Wendell Berry after the 2008 crash

Offline RE

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Re: Small Dam & Micro-Hydro Building
« Reply #108 on: March 06, 2017, 12:03:27 PM »
Stick to your guns, Eddie.  Those devices you're proposing look like the cat's meow.

BTW, you have no worries as far as Eddie "sticking to his guns"and not taking any of my advice.  He never does.

You see, Eddie has no respect for me because I am a Modeler, like the Hardy Kruger character in "Flight of the Phoenix".  Eddie is a "do it in real life" guy before I will respect you, like the Jimmy Stewart character in the movie.  It was only AFTER Hardy's Phoenix actually FLEW and they were saved that Jimmy finally respected Hardy.  The only reason Jimmy went along with Hardy was because there was no other choice, it was try it, or die.  So he tried, and they lived.

Eddie won't listen to anything I say until there is no choice but to listen to me or die.

RE
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Offline RE

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Re: Small Dam & Micro-Hydro Building
« Reply #109 on: March 06, 2017, 12:06:16 PM »
...car alternators work both ways.  One way they crank the engine, the other way the engine cranks them and they recharge the battery.

RE
au contraire, mon frère! :D
Automotive alternators play absolutely no roll in turning the engine; they are strictly a motion input, not output, device.  And they don't motor worth a shit because of the way the field windings are constructed.  Horsepower output is very poor and they heat up quickly.  They do, however, make small motor/generators that are used on things like riding lawnmowers -- dual purpose devices that work as you describe.

As for "working okay for the sailors", yes, they can trickle charge their batteries this way.  Great dual purpose use for a trolling motor that you have on board anyway.

OK, true, starter motor does the job of cranking the engine. So substitute car alternators for the trolling motors.  Those you can pick up REALLY cheap at an auto junk yard.

I still bet I can get more juice out of 3 trolling motors than Eddy can get out of those shallow depth turbines for a lower cost.

RE
« Last Edit: March 06, 2017, 12:08:23 PM by RE »
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Offline Eddie

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Re: Small Dam & Micro-Hydro Building
« Reply #110 on: March 06, 2017, 12:37:27 PM »
1980's model Delco alternators are a common wind turbine hack. Not a lot of output, but they do work. I built one in a class, and I actually own one now, that I  have yet to place in service. The usual thing is to replace the electromagnetic windings on the shaft (rotor) with a Neodymium magnet. I could probably build an old school water wheel that would drive one or more of those. But the low head Powerspout units look better.

Wind is almost useless here, but I spent a few days with Mike and learned a lot about power generation. I recommend him and his turbines to everybody.

http://www.mikeswindmillshop.com/
« Last Edit: March 06, 2017, 12:42:23 PM by Eddie »
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Offline RE

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Re: Small Dam & Micro-Hydro Building
« Reply #111 on: March 06, 2017, 01:05:22 PM »
1980's model Delco alternators are a common wind turbine hack. Not a lot of output, but they do work. I built one in a class, and I actually own one now, that I  have yet to place in service. The usual thing is to replace the electromagnetic windings on the shaft (rotor) with a Neodymium magnet. I could probably build an old school water wheel that would drive one or more of those. But the low head Powerspout units look better.

Water Wheel has the same problem as the Powerspouts.  Insufficient DEPTH.  You need to get down under the water to get the pressure to drive a bigger turbine/alternator or whatever combination it is you use to generate the juice.  The deeper you go, the more power you will generate.



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Offline Eddie

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Re: Small Dam & Micro-Hydro Building
« Reply #112 on: March 06, 2017, 05:38:06 PM »
In power generation, you have to work with what mother nature gives you. A water wheel is a decent alternative for a high flow, low head situation.

You can make the wheel turn with flow. Not as fast as you can turn a turbine with lots of head, but this is Texas, not OFBC. So you turn the wheel and gear down, and lose some efficiency...but you do generate power in a less-than-ideal situation. The little Powerspout Low Head turbines are basically water wheels. Vertical axis water wheels.

I still wonder where the real mill on Mill Creek was. There had to be one. I haven't been able to figure out the local history. Some old person out near the stead could probably tell me. Wherever it was, it was a water wheel, I'm sure. Used to grind corn.
What makes the desert beautiful is that somewhere it hides a well.

Offline RE

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Re: Small Dam & Micro-Hydro Building
« Reply #113 on: March 06, 2017, 06:52:02 PM »
In power generation, you have to work with what mother nature gives you. A water wheel is a decent alternative for a high flow, low head situation.

Whatever you say chief. I'm done discussing this topic with you.  The only thing certain if I make a suggestion is that you won't take it. I'm definitely not going to spend probably 20 hours on a 3D model you will pay no attention to. I am wasting my time with you.

RE
« Last Edit: March 06, 2017, 07:00:31 PM by RE »
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Offline Eddie

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Re: Small Dam & Micro-Hydro Building
« Reply #114 on: March 06, 2017, 07:30:46 PM »
Suit yourself. Didn't mean to piss you off.
What makes the desert beautiful is that somewhere it hides a well.

Offline RE

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Re: Small Dam & Micro-Hydro Building
« Reply #115 on: March 06, 2017, 08:49:19 PM »
Suit yourself. Didn't mean to piss you off.

I telegraphed this in several posts beginning with the post I put up the Flight of the Phoenix clip from.  How you missed this message is beyond me.  Anyhow, best of luck with your damn dam.  You did succeed in pissing me off, intentionally or not.  Suit yourself also.

RE
« Last Edit: March 06, 2017, 10:14:25 PM by RE »
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Offline RE

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Re: Small Dam & Micro-Hydro Building
« Reply #116 on: March 07, 2017, 12:02:04 AM »
Also, before I quit this thread entirely, Marine Sail Water electric generators are optimized for producing electricity, not going the other way from electricity to motive power, so FMs criticism is moot.

https://www.shop.solar-wind.co.uk/acatalog/aquagen_water_towed_turbines.html


An Introduction to Aquagen Towed Water Generators

Aquagens are water towed generators suitable for all sailboats and sailing speeds in blue and coastal waters.

They can provide sufficient power to satisfy all power requirements whilst under sail. The towed turbine travels 1-3 metres below the surface and can therefore be used in shallow coastal waters as well as on ocean crossings.

The well-proven alternator design produces power at low revolutions, reducing drag which varies by output.

The generator is mounted by rope (supplied) to the pushpit. It is quickly and easily mounted and de-mounted. Depending on the Aerogen regulator chosen, these units can charge up to 3 separate battery banks


Sadly, none of these pre-built units are manufactured anymore, likely due to lack of sufficient demand for them, since solar PV panels got so cheap from the Chinese dumping them on the market below cost.  But they are obviously not that complex to build out of an alternator and a drive shaft and propeller.  Also relatively low tech compared to Solar PV and likely you could maintain this technology longer.

What pissed me off here in this thread was the idea was dismissed and ignored.  It could have been fleshed out and we could have had a decent discussion on it.  But nooooo, RE is a MODELER, not a "real world guy".   "His models wont work IRL.  Only us REAL WORLD GUYS know what we are talking about."

I HATE the disrespect I get for being a modeler. This is not the first time by any means and the annoyance has been building inside me.   I don't HAVE a Doomstead to try my ideas out on.  I have only a limited amount of money too, unlike people with lots of money to spend on their prepping.  The best I can do is model right now.  But I get disrespected for that all the time and I am tired of it.  So I finally got pissed off enough to mention it.

Now I feel better.  I vented my spleen on this issue.  :icon_sunny:

Back to Diner Bizness.  ::)

RE
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Offline Eddie

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Re: Small Dam & Micro-Hydro Building
« Reply #117 on: March 07, 2017, 07:11:06 AM »
Sadly, none of these pre-built units are manufactured anymore,

You can still get 'em, I think.

http://www.marinewarehouse.net/ampair.html#Aquair100


Same price range as the Powerspout. Less output, but yes, a possible solution. I understood what you were talking about. I've been a sailor for more than 40 years.

I have no problem with you modeling a solution. But when others have put in lots of R&D and developed an existing commercial product (like Powerspout) you can pretty much assume they've been down the modeling road and spent months or years doing that work already, and they've identified the problems and figured out the best solutions. 

I really don't have the shop to build and test various turbine possibilities. I just want something tried and true, if I can find it. No disrespect intended.






What makes the desert beautiful is that somewhere it hides a well.

Offline Eddie

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Re: Small Dam & Micro-Hydro Building
« Reply #118 on: March 08, 2017, 12:09:50 PM »
I did a little more research on the actual law on building dams here.

Since my creek is non-navigable, I don't need a permit as long as the dam doesn't back up more than 200 acre feet. A quick reference reveals that's over 65 MILLION gallons. I'd guess I'm looking to sequester maybe 20 -30 thousand gallons, so that's less than a drop in the bucket.

Fwiw, bridges aren't so easy. County, state and federal permit. Lots of oversight. Has to meet code. Engineers drawings required. Poured footings with wings in most instances. Since it's on a private road and my neighbors have a deeded easement, it would have to be engineered to support fire trucks, commercial deliveries, and even cement trucks, which weigh over 20 tons, btw.

Here's the FEMA FAQ sheet.

https://www.fema.gov/media-library-data/20130726-1724-25045-9448/fema_p_778_508compliant.pdf





What makes the desert beautiful is that somewhere it hides a well.

 

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