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Well pump set up

Traviss224

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Jun 25, 2022
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Happy Thanksgiving y'all

I have my well pump (1hp) about 300-400' from my house. I am finally about to close my power company account. The grid currently powers my well.

What is a good solar setup that I can do over at the well? I have 2 extra 250w panels from when I did my house setup. I don't want to run power or anything from the house.
 
Do you know the starting wattage? With only two 250W panels, my guess is you will need batteries and an inverter to get any use out of the well. But more panels are probably needed as the idle consumption of the inverter will take up a lot of your batteries when the sun isn’t shinning.
 
There isn't enough information provided to provide input. Is it an AC or DC pump? Do you have well house to put equipment in it? There is also the Grundfos SQFlex pumps that will run directly off of solar.
 
I have a 1hp 240VAC pump. It's 380' down, so this sounds almost exactly like what you might have. I started out with a 48V system with eight Trojan L-16v batteries, fifteen 300W solar panels, a Midnight200 charge controller, and a Schneider XW+6848 split-phase inverter.

I have my panels on rotating mounts, so I can point them Eastward in the morning, and Westward in the afternoon. That lets me provide the 2000W I need to power my pump from 8:00am till 4:00pm. It's been operating problem-free for more than six years now.

If you got ten more of those 250W panels, wiring them 3S4P, and have them on rotating mounts like I do, I'd say you can have a workable system
 

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I have a 1hp 240VAC pump. It's 380' down, so this sounds almost exactly like what you might have. I started out with a 48V system with eight Trojan L-16v batteries, fifteen 300W solar panels, a Midnight200 charge controller, and a Schneider XW+6848 split-phase inverter.

I have my panels on rotating mounts, so I can point them Eastward in the morning, and Westward in the afternoon. That lets me provide the 2000W I need to power my pump from 8:00am till 4:00pm. It's been operating problem-free for more than six years now.

If you got ten more of those 250W panels, wiring them 3S4P, and have them on rotating mounts like I do, I'd say you can have a workable system
It is a 240v unit. Have any of y'all used one of these?

 
Happy Thanksgiving to you too. I have a well that is 400+ feet away and do run it on my new solar system from the house. You said you didn't want to run it from the house, but I do know that some good wire is a lot cheaper and easier than another set of panels, inverter, and a battery setup.

Just so you know, it can be done from the house, even at that distance, in case you change your mind. I just run a 1/2 hp pump on 240v thankfully.
 
Looking at the specifications, I don't believe even the largest unit referenced could run my pump (or yours).

You really need to face reality, and understand that you are not going to run your well-pump with a cheap, low-budget unit.

What I can tell you though, is that once designing your system around your pump, you'll be able to run just about anything else on the unit.
 
Switching to a DC well pump may be less expensive than building a solar system to do it with a standard AC pump. Your well sounds a bit deep to be doing with solar/DC, but not impossible. A lot will depend on your site details: water usage needs, well production, solar availability, if you will have a cistern, etc.

Before committing to an Solar AC system for your current well pump, you might want to check out what a Solar DC well system would look like and cost.
 
If you switch pumps, I would go with a soft start grundfos SQ series. Either way, you are all about the LF inverter and soft starter add on if needed. If your pump just happens to be 3 phase then you have some good soft start options.
 
What are going to do when you need to run the well on during inclement weather or days of clouds? That inverter does not seem to cover those scenarios with battery.

I had a similar problem where I had a deep 240v well pump to run. After checking inrush current, realized I needed a very large inverter and battery system to just get pump to start which would cost a lot. Decided the better approach was to replace the well pump with a Grundfos SQ soft start pump. Best decision I made. My inrush watts to start went from 9600w to 500w. Both have a run wattage of 1400w.
 
For reference : I run a 3HP 240V deep well pump (vevor) to pump water from a creek to a tank. 1.5" Poly Pipe around 900' in length with 450' head.
Have 10kW solar system with growatt 10kW inverter and 2x200AH 48V Lifepo4 powering the whole thing. Works well when pumping but it does feel like I am maxing out the system at startup.
I replaced the pump recently for a pump with a capacitor start and that seems gentler on the start-up.
In my case (and I would guess in most people's cases) it made more sense to build the solar system at the top of the well system and run a 10 GA 240V wire down.
 
The Inverter you suggested Tarvis is designed for a very specific purpose. It will run a pump if two conditions are met: 1. there is solar power available 2. The low water alarm is triggered in the holding tank.
In that setup, the only purpose is to make sure the upper holding tank is filled, so the pump can run intermittently (whenever there is Solar available). The assumption is that another shallow well pump or jet pump will take care of the water pressure from the upper holding tank to the "house". If that is indeed your setup you just need to match the power demand of the pump to the inverter and the panels, with some spare capacity. So if your pump has a startup of 1900W, you need a system that is capable of actually delivering 1900W also in less than ideal conditions (overcast or winter- depending where you are. AZ or AK matters). Adding a battery would lower the demand for solar panels, but your suggested Inverter does not seem to have a battery input.
You mention "i do not want to run wire", but presumably, there is already a wire to the pump currently? Can you not re-use that wire? Anyway, more information on your setup/situation is helpful....
 
My brother and I share a well on our 40-acre property. It is 290' down and is using the Grundfoss SQ pump. This pump works off of AC and DC voltage. We have 4-12v deep cycle batteries in series, 3-145 watt panels providing power to a Midnite Solar Kid SCC. No inverter. This is all 8 feet down in a well pit and has been providing both of us with water for 5.5 years.
My brother draws his water directly from the well, I have a 1600-gallon cistern buried below the frost line that the well fills automatically.
The only problem we've had with this setup was last year the well pit flooded due to heavy snowmelt. We pumped the pit dry, I replaced the pressure switch on the tank and we were back in business. The four batteries were submerged and suffered no damage! Still using them today!
Oh, I also had to replace the Midnite Kid. It didn't get submerged, however, the display was wacky.
 
How can the pump have an inrush of 500W when it needs 1400W to run? That's physically impossible? Did you mean 1400W + 500W = 1900W?
I have a Grundfos SQ-10-160. Mine starts at zero and quickly ramps up to about 1000w. I'm not sure how they do it. There are a few tricks to not have a surge at start. 3 phase is the easiest with a VFD. Used all over industry. Saves tons of power.
 
What I can tell you though, is that once designing your system around your pump, you'll be able to run just about anything else on the unit.
Exactly. After designing and installing a few off grid systems this became very clear to me. Once you've got an inverter(s) capable of STARTING a standard well pump everything else get's quite easy in comparison.

I have a Grundfos SQ-10-160. Mine starts at zero and quickly ramps up to about 1000w. I'm not sure how they do it. There are a few tricks to not have a surge at start. 3 phase is the easiest with a VFD. Used all over industry. Saves tons of power.
It's brothers, the SQE (constant pressure) and SQF, are very impressive as well. Ideal for off grid applications.

I would always run my customers through the math of sizing the system for thier existing pump vs. getting a new pump. In many cases swapping out the old school well pump with a Grundfos' was equal or cheaper. If you've ever stood next an inverter and heard it groan and grunt to start a traditional well pump most would be leery of asking it to do it year after year.
 
How can the pump have an inrush of 500W when it needs 1400W to run? That's physically impossible? Did you mean 1400W + 500W = 1900W?
Totally possible and 100% true. Recommend you lookup the Grundfos SQ 3/4hp series. It starts at 500 watts and ramps up to running wattage of 1400w in about 2.5 seconds.
 
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I guess I missed replying to this.

My pump is 240v. I calculated like 1900 watts. I don't remember off hand but I think it was 7.8 amps. I'll check again.

I am doing a 3k eg4 system. I am in the middle of upgrading to lithium so I can always use my lead acid batteries for the pump. I am building a shed around it and want to store that well solar system in it.
 
@Traviss224 I recently set up a system to power a 2HP well pump. Here is the thread, in case it's helpful to you https://diysolarforum.com/threads/off-grid-container-48v-system-120-240v-well-pump-on-solar.72417/

You will need to measure or estimate the current draw of your pump on start up, which will be significantly higher than the running current for non soft start well pumps. It is best to measure, with a multimeter that can measure inrush. In some cases pumps will draw 5X the running current on startup. Once you know that startup current/LRA of your pump, you inverter then needs to be sized to handle this startup surge current.

For actually running the pump long enough for your needs, you will need to determine the total number of hours you expect to run the pump each day and multiple this by the running current to get your expect kWh's. Then size your solar array and battery bank in order to handle that daily power requirement.

If you only have two 250W panels, you will need a large battery bank so that you can trickle power in for multiples days and then run your pump. If you are able to add more panels to your array, you will be able to reduce the amount of battery capacity required and maybe even not need batteries at all if the array is sized large enough to cover the power needs of the pump and you can get away with pumping during the day only.
 
Last edited:
I guess I missed replying to this.

My pump is 240v. I calculated like 1900 watts. I don't remember off hand but I think it was 7.8 amps. I'll check again.

I am doing a 3k eg4 system. I am in the middle of upgrading to lithium so I can always use my lead acid batteries for the pump. I am building a shed around it and want to store that well solar system in it.
If your pump running is ~1900w, your pump starting will be around 10kw if not using a Grundfos or similar softstart pump. Need a lot of inverter and battery for that.
 
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