Help for building a solar solution for a .33 horsepower AC well pump for watering livestock in S. Texas

[Jnieto]

My wife and I bought 12 acres of raw land in S. Texas, and we use this system to power our RV and our water well while we have our house built. We put this system together, built the ground mount for the solar panels, and built the solar shed that houses the equipment. We bought everything except the solar panels from Signature Solar as a kit and we figured out how to do it from videos and the manual. We bought the solar panels, used, from Santan Solar

2 – EG4 6500 ex inverters

6 – EG4 LifePower4 Batteries

38 – Solar panels (13160 watts)

2 – EG4 Chargeverter 5KW

Firman T7573 TriFuel generator form Costco


Because of our success with this project a friend of mine asked if I could help him make his livestock water well run on solar. He has a:

SHYLIYU Submersible Pumps 2.5" OD Pipe 110V/60HZ 0.25KW 0.33HP Stainless Steel 1" Outlet Submersible Bore Pump Deep Well Pump with Control Box for Farm Irrigation.

That is for a 60ft well that is used to water livestock and runs 30-45 min per cycle one to two times a day. The well is out on his pasture, and he said he could put up a metal shed near the well to house the equipment if necessary.

Would the following setup work for his needs?

EPEVER MPPT Solar Charge Controller 40A 150V PV Solar Panel Controller

GoWISE Power 1500W Pure Sine Wave Power Inverter 12V DC to 120 V AC

One 400-500watt solar panel

I’m not sure what battery to use,

Lithium like this one: Ampere Time 12V 100Ah, 1280Wh Best RV Lithium Battery

or

AGM Like this one: WEIZE 12V 100AH Deep Cycle AGM SLA VRLA Battery for Solar System

Also, what size wire and fuse or breaker would be best?


Thanks for your help!

 

[peakbagger]

FWIW, centrifugal pumps are notoriously inefficient. Far better to do with positive displacement style pump which is far more efficient. Ideally have a storage tank on the ground that fills up slowly from a DC pump over a period of hours and then drain the tank to feed the livestock. Put a float switch on top of the tank that shuts down the DC pump when its full, otherwise the DC pump keeps running. No need to an inverter or even batteries.

 

[Jnieto]

FWIW, centrifugal pumps are notoriously inefficient. Far better to do with positive displacement style pump which is far more efficient. Ideally have a storage tank on the ground that fills up slowly from a DC pump over a period of hours and then drain the tank to feed the livestock. Put a float switch on top of the tank that shuts down the DC pump when its full, otherwise the DC pump keeps running. No need to an inverter or even batteries.

Thank you, I had the same thought but since I'm fairly new to this I wanted to get the opinions of more knowledgeable people. Do you think this one from amazon would work?

ECO-WORTHY 12V DC Submersible Deep Well Pump, MAX Flow 3.2GPM, Max Head 230ft, Water Pump Powered by Solar or Battery for Well, Livestock Drinking or Tank Filling​

 

[peakbagger]

The quick look I did does not say what type of pump this is, my guess is its centrifugal. You want a positive displacement pump like Grunfos SQ flex

Grundfos has a free on line courses on off grid pumping This one may be of interest https://www.grundfos.com/us/learn/ecademy/all-courses/solar-pumping-systems

I have one of these Nemo diaphragm pumps on my watering system for my garden. It pressure rating is overkill for my application which pumps out of 17 foot deep surface well up to plastic tank mounted on top of pile of firewood. The system consists of a pump, three 25 year old 12 volt solar panels (wired in parallel) and a float switch mounted up side down in the top of the tank. If the tank is below full, the float switch is hanging down into the tank and the switch is closed so the pump runs, when the tank fills up, the switch floats up and opens the contact. No batteries, no charge controlers. The tank is 300 gallon IBC tote tank. No batteries or electronics. The tank is the "battery"

Hard to beat the price on the Nemos, the key thing is that the water can not have any solids in it as a cheap diaphragm pump is not intended to pump "chunks". This may mean that the pump needs to be screened in tube if solids are an issue.

The key with pumping is you want to run a smaller pump for longer periods of time as starting and stopping the flow take a lot of sure power. The tank makes it so you do not need the fast start stop.

 

[DIYrich]

Thank you, I had the same thought but since I'm fairly new to this I wanted to get the opinions of more knowledgeable people. Do you think this one from amazon would work?

ECO-WORTHY 12V DC Submersible Deep Well Pump, MAX Flow 3.2GPM, Max Head 230ft, Water Pump Powered by Solar or Battery for Well, Livestock Drinking or Tank Filling​

I wouldn't buy an inverter with an integrated battery. Just read the comments about getting a battery replacement.

Grid power available? If not, then you need batteries good for a few days. Unless the cattle can go somewhere else for water. Freezing Temps? If so then a heated system with LiFePO4 batteries, or lead acid unheated.

If the watering is not critical, then there is a growatt that is solar direct to pump inverter without battery (can connect to grid).

Regarding battery wire: for a 12v system, 3,000 watts surge is 250 amps. 1/0 wire is 245 amps chassis, and should be ok for really short run. A 200 amp class t fuse should work. I think the Blue Sea version can pass 120% for more than a few seconds.

 

[Jnieto]

The quick look I did does not say what type of pump this is, my guess is its centrifugal. You want a positive displacement pump like Grunfos SQ flex

Grundfos has a free on line courses on off grid pumping This one may be of interest https://www.grundfos.com/us/learn/ecademy/all-courses/solar-pumping-systems

I have one of these Nemo diaphragm pumps on my watering system for my garden. It pressure rating is overkill for my application which pumps out of 17 foot deep surface well up to plastic tank mounted on top of pile of firewood. The system consists of a pump, three 25 year old 12 volt solar panels (wired in parallel) and a float switch mounted up side down in the top of the tank. If the tank is below full, the float switch is hanging down into the tank and the switch is closed so the pump runs, when the tank fills up, the switch floats up and opens the contact. No batteries, no charge controlers. The tank is 300 gallon IBC tote tank. No batteries or electronics. The tank is the "battery"

Hard to beat the price on the Nemos, the key thing is that the water can not have any solids in it as a cheap diaphragm pump is not intended to pump "chunks". This may mean that the pump needs to be screened in tube if solids are an issue.

The key with pumping is you want to run a smaller pump for longer periods of time as starting and stopping the flow take a lot of sure power. The tank makes it so you do not need the fast start stop.

Thank you for the link. That was very helpful. The Nemos is interesting too, I'll show him both options and let him choose.

 

[Jnieto]

I wouldn't buy an inverter with an integrated battery. Just read the comments about getting a battery replacement.

Grid power available? If not, then you need batteries good for a few days. Unless the cattle can go somewhere else for water. Freezing Temps? If so then a heated system with LiFePO4 batteries, or lead acid unheated.

If the watering is not critical, then there is a growatt that is solar direct to pump inverter without battery (can connect to grid).

Regarding battery wire: for a 12v system, 3,000 watts surge is 250 amps. 1/0 wire is 245 amps chassis, and should be ok for really short run. A 200 amp class t fuse should work. I think the Blue Sea version can pass 120% for more than a few seconds.

Thank you! There is no grid power available, currently he is using a generator to pump the water. I'll let him know what his options and see what he wants to do.

 

[Steve777]

I would second the comment about not using an AC centrifugal pump, especially for low volume occasional pumping. Way too inefficient. There are quite a few DC submersible pumps systems out there. I have used RPS and generally had good luck with them. But there are others too.

I would also agree that having a water storage tank (maybe the animal's watering tank) for storage is a good way to go. Ideally you'd want to pump during the day when the sun's out. Properly sized tank may allow you to skip the batteries.

 

[hwy17]

Growatt sells a pump inverter that might uniquely apply to this. I think it needs a 240v grid supply and feeds in solar when available, no battery necessary. Would only shave off daytime usage of course.

 

[diytx]

So you have 38 panels that produce 346 watts each?

Then you have 6 5kWh batteries for 30kWh storage?

I am looking at doing something similar and just starting the process. That seems like a massive system though to just power an RV and well pump?

 

[Johno1066]

So If centrifugal pumps are so inefficient why are they the backbone of process industries? Positive displacement pumps have a place but not due to their efficiency for sure but for specialised applications high pressures being one of them. Most modern well pumps are centrifugal and manage quite well. Many centrifugal well pumps work into a closed pressure controlled system without the need of overhead storage containers. Centrifugal jet pumps are also popular with shallow wells and both of these can be easily managed with an EG4 3000 low cost inverter without any problem as I am running both of these type of pumps on my home water system. I run these 1/2 HP pumps on my well although it is only 40 feet deep. I run two cause if one fails I can switch to the other and repair the problem pump without any disruption to my water supply just as I run 2 EG4 3000 in parallel so that if one fails I can get by until the faulty unit is replaced or repaired.

 

[efficientPV]

If he was my neighbor, I'd set him up for $40 + panels and he could use his existing pump and no batteries.

 

[Jnieto]

Growatt sells a pump inverter that might uniquely apply to this. I think it needs a 240v grid supply and feeds in solar when available, no battery necessary. Would only shave off daytime usage of course.

Thanks for the tip, do you remember the name of the pump?

 

[Jnieto]

So you have 38 panels that produce 346 watts each?

Then you have 6 5kWh batteries for 30kWh storage?

I am looking at doing something similar and just starting the process. That seems like a massive system though to just power an RV and well pump?

It is a lot but with the high temps this summer and trying to keep this RV cool takes a lot of energy. We've been using 50-70kw per day this summer. We are also going to use this solar power set up for the house when it's done.

 

[Jnieto]

So If centrifugal pumps are so inefficient why are they the backbone of process industries? Positive displacement pumps have a place but not due to their efficiency for sure but for specialised applications high pressures being one of them. Most modern well pumps are centrifugal and manage quite well. Many centrifugal well pumps work into a closed pressure controlled system without the need of overhead storage containers. Centrifugal jet pumps are also popular with shallow wells and both of these can be easily managed with an EG4 3000 low cost inverter without any problem as I am running both of these type of pumps on my home water system. I run these 1/2 HP pumps on my well although it is only 40 feet deep. I run two cause if one fails I can switch to the other and repair the problem pump without any disruption to my water supply just as I run 2 EG4 3000 in parallel so that if one fails I can get by until the faulty unit is replaced or repaired.

Do you have a battery connected to your system? If not, how is it connected? Solar panel to EG4 3000 to well?

 

[hwy17]

Thanks for the tip, do you remember the name of the pump?

I thought he already had grid power. If not, then swapping it out for a DC straight solar powered pump might be better.

Growatt 2.2kW 3HP Solar Pump Inverter l Water Pump Inverter | Grid-Assisted | SPI 2200TL2-HV

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

 

[Johno1066]

I have 6 EG4 batteries , but I am running the whole house. For a small pump running for such a short time every day I am sure you could get by with just one battery or even a few lead acid 12 volt batteries in series.

 

[Johno1066]

To run an EG4 3000 watt inverter you will need a PV input of greater than 120 volts, so for me I used arrays of 5 240 watt panels from Santan Solar at $40 a piece. You might get away with 4 panels to get to 120 volts, the power output max would be in the range of 7 amps and if that pump is really 0.33 HP it would be aound 250 watts so it should not draw anywhere near 7 amps and with a battery connected to the inverter the battery would provide for the initial starting surge. The full load of an EG4 3000 will be 25 amps so you should not have a problem .Depending on the distance from the inverter to the pump head #10 or even #12 would be sufficient for the pump.