Roger Leslie's posts

I want to thank all of you for the excellent information!!!  You have been extremely helpful!!

After running the numbers, even if I can achieve 80% efficiency, it will take over 16 years to get a return on my investment (after tax credits).  So this brilliant idea is going into a rather large pile of my other brilliant ideas.

For those who have suggested a solar water heater, I agree that it would be a great idea.  Unfortunately, no one location on our land gets more than 3-4 direct sunlight during the winter.  We live in a narrow valley next to a beautiful stream.....with very little head.

Thanks Again

What I WANT to do:

- Hydro generator will produce 24V @75W - 90W depending on how much rain feeds the stream.
- Power will run to our house 120' from generator (I have not attempted to determine wire size yet).
- Power will run directly into a dual contact thermal-relay-switch. 
- Normally the switch will feed a 60 gal. water heater (A) with dual heating elements.  The bottom element, tied to the relay switch, will be a 24V-100W element....the top element will be a regular 110V element.
- (A) is filled with glycol to be used in a closed-loop radiant floor heating system.
- When the temp in (A) reaches 120f, the switch will transfer the current into a domestic water heater (B).  The bottom element in (B) will be 24V and this is used as the dump load.
- When the temperature in (A) falls below 100f, the relay switch will redirect the current back to (A).
- We do NOT want to use batteries in the system, but I realize that I may have to.

My primary concern at this point is the heating element.  The volume of water flowing in the generator system will vary when it rains, so the wattage output will fluxuate.
This may require the batteries to assure the element receives proper wattage.  Correct??

Also, I have found a relay switch for this application.

Thanks again
Roger

Thanks John    Your answer leads me to my next two questions:  a) since the voltage & wattage from the hydro generator may vary slightly, what wattage should the element be?  I have found DC elements from 20W to 600W.  The generator should produce a max of 180W.

b) Once the fluid in the first water heater reaches a set temperature, I want the charge to be diverted to a second water heater DC element.  What type of temperature controlled relay  switches would work in this type of application?

Thanks
Roger

John

Thanks for the help!!

Are you saying that I should use an AC heater elements rather than one of the DC units?

If I understand you correctly,  I can hook the hydro generater (12V - 120W) straight to the element without a
DC-DC converter to assure a constant 12V.  If so, that is nirvana.

Roger

To be more specific, I want to connect a Auqair In Stream Generator to a DC water heater element using a DC-DC converter (like the Buck Booster PST-DC/2812-8) between the generator and the element.

I'm trying to find a way to eliminate batteries.  The power from the Generator will only be used to heat water.... nothing else.  I need something between the Generator and the dc heating element to buffer the charge.  Since the generator provides power 24/7/365, I don't need a reserve power source.

If I place a voltage regulator between a micro-hydro generator and a battery bank, does the regulator lower the voltage and supply a constant voltage to the battery bank?

thanks