Please help if you are able

Welcome to the forum Derek,

I will give the suggested solution to all things solar/battery powered... Conservation and picking the most energy efficient device you can--Almost always cheaper to conserve electricity than to generate it.

There are some very nice smaller pumps from Grundfos and others that are very "solar friendly". Some operate from 120/240 VAC at ~900 Watts and no starting surge current (around 1 HP), and there are versions that will take power directly from multiple sources (solar panels, higher voltage battery banks, and even AC power from mains/generators/inverters--Same pump). That is the Grundfos SQFlex series.

https://www.solar-electric.com/residential/solar-water-pumping.html?manufacturer=74

Our host has a variety of solar capable water pumps (and feel free to call them for sales and engineering support--Our forum here is based on volunteers answering questions):

https://www.solar-electric.com/residential/solar-water-pumping.html

Of course you have to match the well specifications (depth of water, well GPM rating, run dry protection, etc.) as needed...

Now that I have got that out of my system... Lets say you know more about wells and pumps than I do (very easy). And that you have sized your needs and matched it to the pump's specifications.

The easiest solution at this time (as far as I know--Again, I am not in the solar/water pumping business) is to pick a 3 phase inverter rated for use with a Variable Frequency Drive.

More or less, you connect the power source (solar panels, battery bank, genset, etc.) to the appropriately rated VFD, connect the VFD output to your 3 phase motor. Program the VFD for your motor power curve/other needs (some can be setup for constant pressure/variable  pumping, etc.). 

A VFD is a variable frequency AC inverter... It is programmed (usually) to start the motor at a low frequency, and "slowly" bring the motor up to its set point RPM.

Also, a "solar capable" VFD can monitor the input power available from the solar array and run the pump at a slower RPM in the early morning/late afternoons. I.e., vary the pump RPM to match the available solar energy.

Using a 3 phase motor takes care of starting issues (no capacitors) as 3 phase pumps "naturally" have a rotating field (vs single phase induction motors which need a starting capacitor/switch to create a rotating field).

There are lots of issues and options out there (and you have to find a knowledgeable source for solar powered VFDs--If that is what you are looking for).

There are other alternatives too... "Slow pumping" from a well to a tank/holding pond. Then using a surface pump to supply 60 PSI for a cabin/home.

To give you an idea of what was out there in 2012, is an article from India about solar+vfd:

https://www.thehindu.com/news/cities/Vijayawada/harnessing-solar-energy-to-run-a-3phase-ac-pump/article3753770.ece

Here is an example (again from 2012) on what a 2.2 kWatt solar VFD can look like (no idea if company is still in business--Link to give you an idea what to look for):

http://www.ttnet.net/ttnet/gotoprd/EN300/040/0/1383639383831343631353336313939303034313130393.htm

Some more VFD pumping general information:

https://www.veichi.org/solutions/water-supply/pump-vfd-or-vsd-for-constant-pressure-water-supply-system.html

There are a lot of details that need to be addressed--And if you can find a local to your (southern Nevada?) that knows VFDs, motors, and pumps--That would be great.

Sorry for the older links... Don't get too many questions for larger water pumping systems here.

-Bill

I am so sorry about your friend and his daughters.

To your needs... First thing is to save the crop and you should buy/rent a generator and get the pump up and running. Quick and relatively inexpensive first step.

Renting/borrowing a generator can help let you figure out what your power needs will be. You will need to look at the pump and confirm that it is a 240 VAC single phase pump or possibly a 208 or 240 VAC 3 phase pump.

Besides water pumping, will your need power for other things (home, workshop, fans for drying, lighting, etc.)?

What fuel will be available? Diesel, gasoline, propane?

Is there any electrical service panel(s) left that give you an idea of what size genset/other loads are used/needed?

And, frankly, figure out the cost of short/long term solutions (genset, fuel, plus solar) vs the value of the crop.

Just to take a guess and do an example here. Say running a 5 kWatt genset, gasoline, and the pump takes 2.5 HP (probably takes less, but you would need to measure the loading). You don't want to oversize the genset, that can be a big waste of fuel. A standard gasoline genset is most efficient/best used around 50% to 80% of rated load. If you get an inverter-generator (such as a Honda euXXXX family, they can run fairly efficiently down to 25% of rated load--A standard genset uses about the same amount of fuel/Gallons per Hour at 50% of rated load of rated load). The genset also needs to be large enough to start the pump (starting surge).

Taking a guess that the genset will use around 1 GPH for every 4,000 Watts of load, a genset running a 2.5 HP pump 12 hours per day would be (assuming 70% electric motor efficiency):

• 2.5 HP * 746 Watts per HP * 1/0.70 efficiency = 2,665 Watts running load
• 2,664 Watts * 12 hours per day = 31,968 WH per day (= 32. kWH per day)
• 31,968 WH per day / 4,000 WH per gallon (gasoline genset rough efficiency) = 7.992 gallons of gas per day
• 7.992 gallons per day * $3.00 per gallon = $23.98 per day

The above numbers are pure guesses, and if the water pump is not operating at 100% load but only 50%, the fuel usage will be less.

Generator pricing will be all over the map, to very inexpensive generators that may cost less than $1,000 (inexpensive 7 kWatt genset from Costco) to something like a $5,000 7 kWatt Honda eu7000i inverter-generator (quieter, more fuel efficient at lower loads).

https://www.costco.com/firman-7500w-running--9400w-peak-tri-fuel-generator.product.100648883.html
https://powerequipment.honda.com/generators/models/eu7000is

If you assume that a good gasoline genset will run for 2,000 hours, at 12 hours per day that is:

• 2,000 hours / 12 hours per day = 167 Days (less than 1/2 a year)

If you go diesel--Price is all over the place (not cheap to very expensive). As an example, random diesel genset from Amazon:

https://www.amazon.com/Generac-6864-Starting-Portable-Generator/dp/B010T243GU

~$4,000, runs around 30 hours on 12 gallons of diesel at 50% load (5,000 Watt rated, 2,500 Watts is 1/2 load):

• 2,500 Watts * 32.4 hours * 1/12 gallon tank = 6,750 WH (6.8 kW) per gallon of diesel
• 32,000 WH per day load (2.5 HP pump) / 6,750 WH per gallon = 4.74 gallons of diesel per day
• 4.74 gallons per day diesel * $3.50 per gallon = $16.59 per day (diesel

So better fuel efficiency for diesel... The above is a very noisy generator (no sound insulation--I guess). And diesels tend to be more efficient than gasoline/propane gensets at lighter loading (less than 50% of rated output, fuel flow will decrease due to inherent efficiencies of Diesel engines).

I have not gotten into the solar side of things... Solar driving a 2.5 HP pump will be expensive, very very expensive.

Any idea of what size of solar power system was installed? Just the solar panels alone would be on the order of (for a full offgrid solar power system with AC inverter, battery bank, etc.). Fixed array facing south, optimized for summer usage, Las Vegas NV area:

http://www.solarelectricityhandbook.com/solar-irradiance.html

Las Vegas
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 69° angle:
(Optimal summer settings)

Jan	Feb	Mar	Apr	May	Jun
4.04	4.68	6.08	6.88	7.27	7.32
Jul	Aug	Sep	Oct	Nov	Dec
6.83	6.36	6.07	5.40	4.39	3.92

• 32,000 WH per day * 1/0.52 off grid system efficiency * 1/6.07 hours of sun (October) = 10,138 Watts of solar panels minimum
• 10,138 Watts of panels / 250 Watt solar panel = ~41 relatively large panels mounted to racking/etc.

If they pulled the solar panels, inverter, battery bank out of a shed, and the panels were not rack mounted--Then your friend was probably running just a genset and did not use solar (at this time), or had a much smaller solar system just to run some LED lighting, cell phone, laptop, etc. stuff in the shed/building at night...

I know that this is a solar forum, but I doubt that off grid Solar would be cost effective in the short term--And would be difficult to order/install/bring online in the few days needed to save the present crop.

Finding the "right size" of diesel genset to run your pump--Just looking at United Rentals (Las Vegas NV):

https://www.unitedrentals.com/marketplace/equipment/light-towers-generators/diesel-generators/generator-19-29-kva-tier-4#/
"Smaller" diesels are not that easy to find... So you may end up with a larger unit which will not be cheap to buy or rent.

I will stop here... So many questions and pure guesses above. Your thoughts/corrections/etc.?

-Bill

It is possible that the owner of the land has a 2 week limit... But (assuming this is in) California has setup a pretty complex regulation matrix for generators (heavy trucks, "portable" industrial equipment, etc.). Here is a FAQ that attempts to put out the framework:

https://ww2.arb.ca.gov/sites/default/files/2020-01/PERP_FAQ%20.pdf

It was getting to the point, for example (my very rough understanding), if you went to buy a part for your forklift, the parts store was asking for your name, address, equipment type/model, and serial number(s) just to buy the part.

And that data was sent to the state--If your equipment was not already registered and regulated, it would be now.

Much of the laws/regulations that "allow" generators only applies to "backup generators" of relatively small size.

In this case, it would be prime power source for water pumping--Probably a much "different" animal (for California).

Note that many of these requirements can be based on the rules for local "districts"--So what is allowed in XYZ air district may not be allowed elsewhere.

The state is attempting to control sources of air (and other?) pollution sources (getting rid of old/dirty tech and replacing with new tech diesels, limiting the use of any pollution source, etc.).

Sort of similar to what happened to over the road trucks and basically outlawing (rather than grandfathering) older/dirtier diesel trucks (owners would have to move trucks out of state/down to Mexico, etc.).

-Bill "I certainly may be wrong on the details" B.