# Off grid well pump...



## Al Yaz (Jun 13, 2017)

Looking for advice on a new well pump. Our current well pump is a 240v unit and is about ten years old. It was put in by the original owners of the property that we now own. The well pump is our largest power draw (at any one time). I have my system set to not ‘auto start’ the gen for 12 minutes (enough time to fill our three pressure tanks). However on cloudy days, if the batteries are getting low, the pump will trigger the gen to start.

So my questions are:
1. are the Grundfos (sp ?) well pumps that more efficient than the other makers?;
2. what determines being able to use a 120v Grundfos well pump instead of a 240v well pump? (is it the depth of the well, the head, distance from well to pressure tanks?);
3. and how much sun do you need to consider a solar well pump? can they actually work here in the PNW coastal area that doesn’t see much sun or bright light in the winter months?
3(a) if a person went to a dedicated solar well pump set up, what is required? would it require, 1. a specialized solar well pump. 2. batteries and how much is realistic? 3. solar panels, again how much is realistic. How do you go about figuring out what is needed to fill your pressure tanks?
3(b) and how do you know if it’s better/cheaper to just augment your current batteries and panels versus a stand alone solar well pump/batteries/solar panel set up?


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## ET1 SS (Oct 22, 2005)

To meet the demand of a 240vac well pump, I was forced to go with a larger inverter that needs a 48vdc battery-bank.


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## Al Yaz (Jun 13, 2017)

Hmmmm, copy... just thinking about this out loud here... so what you are saying is that a 48v battery system would provide more ‘head room’ for the well pump. That I am sure is not the correct technical term but just trying to make sense of it...

So if a person didn’t want to do a 48v battery bank and new inverter I wonder if there is a more efficient way to pump... better pump etc.


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## wy_white_wolf (Oct 14, 2004)

I run a solar pump at the ranch for watering the orchard. Here's my setup https://www.homesteadingtoday.com/threads/we-got-water.528021/#post-7279887

My needs are much different than yours but if I were you I'd look into a 2 pump setup. The main advantage of a 2 pump setup is it decreases the large draw from the single pump setup you are seeing.

In a 2 pump setup you have a solar slow pump about like mine that runs solar direct to fill a cistern. Running solar direct it only puts out 1 to 2 gallons a minute but does it as long as the sun is shining and the cistern isn't full. Solar panels put out some power even when cloudy so you may have to oversize the array some to compensate for them. My setup with the 120 watt panel will easily put out 1000 gallons on a good sunny day so if you don't want to over size the panel you can increase the cistern size to carry you through the cloudy days just like a battery bank does.

Then a second pump from the cistern to pressurize the house. Only the second pump is ran off the battery bank and since it doesn't have to get the water all the way out of the well it doesn't pull such a large draw. This also gives you 24/7 pressurized water for the house when your well pump only has to run on sunny days.

WWW


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## Steve_S (Feb 25, 2015)

I use a Grundfos SQ-5 Softstart 120v deep well pump, it sits 230' deep inside a 6" bore.
KEYWORD for Solar - "Soft Start" you do not want a massive pull on your system to start the pump... unless you want to hurt your system, period! 

I have a 50 Gallon Pressure Tank inside my Pump House / Power House (Solar electronics & batteries all there on other side). My Solar System is 24V with 3Kw Inverter/Charger. Water from the Pump house travels to the cabin via 3/4" PEX underground with that run being 65 feet and I have no pressure issues and run On Demand hot water as well. 

Due to my locale, I have an old LPG RV / Camper furnace (uses 12v, gave it it's own battery & 1 solar panel) that ensures the Pump/Power house remains @ 40F over winter, not hard to do as the building is also hyper insulated, used $30 worth of propane all last winter (and it was a nasty one too here).


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## Al Yaz (Jun 13, 2017)

Steve_S said:


> I use a Grundfos SQ-5 Softstart 120v deep well pump, it sits 230' deep inside a 6" bore.
> KEYWORD for Solar - "Soft Start" you do not want a massive pull on your system to start the pump... unless you want to hurt your system, period!
> 
> I have a 50 Gallon Pressure Tank inside my Pump House / Power House (Solar electronics & batteries all there on other side). My Solar System is 24V with 3Kw Inverter/Charger. Water from the Pump house travels to the cabin via 3/4" PEX underground with that run being 65 feet and I have no pressure issues and run On Demand hot water as well.
> ...


Copy thanks. Is it the Grundfos SQ Flex series pump you have?

This is what our well / pressure tanks / house location looks like. Our well head is about 15’ lower in elevation than where the pressure tanks are located and there is about another 15’ to where the house is located. The well is about 120’ deep. The well is about 100’ from the pressure tanks. The pressure tanks are about 75’ from the house.

As there are no ‘service people’ around this area, how does one know if a Grundfos sq-5 softstart in 120v will work for this application?


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## Steve_S (Feb 25, 2015)

Service People ? A Plumber ?

Grundfos Site & Info on SQ series: 
http://www.grundfos.com/products/find-product/sq.html

As for 120v VS 240v, both are capable of doing what you need. I used 120V simply because I have no 240v, have no use for it and am 100% off-grid solar. I'm power frugal as well as frugal on many other things... worked too hard for what I have and don't believe in giving away my hard earned cash... especially to Big Power Co hostage takers. (Power rates have climbed over 140% in the past 8 years here... so... happy to be free)


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## Al Yaz (Jun 13, 2017)

Yes we are 100% off-grid solar too. I will email Grundfos to see if there is someone there that will work with me via email and / or phone to try and figure this out. See that’s where I get confused, I would have thought that a 120v pump would always be a lower draw than a 240v pump, even if both are soft-start. That’s how little I know about well pumps.

Only about 40 people live here so plumbers are like finding a dental surgeon on island ;-)


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