The maximum power horses !

[bcroe]

i have a well with a 20hp pump already fixed on it. So, regardless of
the head, flow or expenses. i need to run this pump using solar power.

I am trying to understand how a 20 hp pump got installed, when there was no way to power
it? Maybe there is a diesel generator there?

The problem with AC motors, is they tend to need steady full power to run. Solar is anything
but steady & predictable over the day and year. Trying to store up power in batteries to level
the power on this scale would require boxcar loads of batteries, along with all sorts of operating
complications. In the end you need the diesel anyway to preserve the batteries. And the
complexity will hurt the efficiency.

DC pumps are available with controls to make use of whatever power a solar system can deliver
at that moment. A big tank can store water overnight or even days when solar output is weak.

There are AC motors and controls designed for variable speed. See the latest generation of
rail locomotives. Solar may eventually have such equipment, perhaps not today. I doubt it
will use your current stock AC 20 hp pump. Bruce Roe

[inetdog]

I found this.

http://www.youtube.com/watch?v=b_jCy...ature=youtu.be

As I do not speak or read Arabic, I can't help you at all on understanding that system.

[amd711]

I found this.

http://www.youtube.com/watch?v=b_jCyGivFmk&feature=youtu.be

[Sunking]

My service, heat pump, elevator etc are 4 wire 3 phase

Most likely the controls use L-N voltage, but the 3-phase motors do not. I assume you have something like 208/120 wye service. L-N is the 120 volts and line to line is 208. You would have to have a wye service to get your 120 volts or whatever standard line voltage you use for receptacles.

[russ]

No neutral required, it is 3-phase and and they do not use a neutral.

My service, heat pump, elevator etc are 4 wire 3 phase

[paulcheung]

Can a 50KVA generator start this thing? it would be much cheaper to use a generator to run this thing.

[Sunking]

if it's an AC pump and 20HP then that is going to be a 406V pump, which is 3 phase AC with a neutral.

No neutral required, it is 3-phase and and they do not use a neutral.

[thastinger]

if it's an AC pump and 20HP then that is going to be a 406V pump, which is 3 phase AC with a neutral. You have just exceeded my level of experience, as stated above, you need to hire a professional design company

[amd711]

thastinger

1. You're positive there is no way to get grid power to that location for under 100K?

that is right.

2. You need to go about this from the other direction. If a smaller pump would do the job, it'll be less expensive to buy the proper size pump than to add PV to run the 20HP...assuming the proper size isn't 19HP anyway.

well, maybe but i need to know what to do next. (suppose it is 10hp)

3. does everything need to come from this one well and pump?

Yes.

your DC pump

It's an AC pump.

run time is going to be limited to the peak sun hours, don't know if that will do the job for you or not but, if not, maybe a couple of smaller pumps running the same time would.

what about batteries?

4. Where are you located and what months of the year would this pump be needed?

- Israel.
- all 12 months.

Thanks

[Sunking]

AMD what you want is possible and if you want to do this will take a professional engineering design build firm to construct. The subject is out of scope of a DIY forum. I suggest you hire a professional for consultation.

[thastinger]

AMD, ok, so you're serious about running this pump from PV. Below are some questions and observations

1. You're positive there is no way to get grid power to that location for under 100K?
2. You need to go about this from the other direction. If a smaller pump would do the job, it'll be less expensive to buy the proper size pump than to add PV to run the 20HP...assuming the proper size isn't 19HP anyway.
3. Is it possible to drill another well or does everything need to come from this one well and pump? I ask because your DC pump run time is going to be limited to the peak sun hours, don't know if that will do the job for you or not but, if not, maybe a couple of smaller pumps running the same time would.
4. Where are you located and what months of the year would this pump be needed?

[amd711]

The guys are all saying it isn't impossible to run a pump but not practical from a cost basis. Not a solution I don't think.

I do not care about money , should it cost 200k $ , so be it
i care about technical feasibility, if it is possible please show me how to design such system.

should I consider the pump starting current in chosing the inverter? if yes, how ?

also, specifications of the charge controller, PVs and batteries(suppose that i need to run it for five hours a day) but more importantly, i need to know how to calculate these specifications using the given information.

This well is for farms irrigations, it is meant to supply a large amount of water for far distances.

but in case it is impossible, (and i need to replace the pump) what is the maximum rating suitable for solar power (of course in case of AC pumps) and how to design such systems?

[russ]

Do you mean that it is possible to run any pump using solar power (say 20 hp vertical pump)
if so, could you please guide me on how to design a solar system that handle such power. for example, what are the main components and how to calculate their specifications.

i have a well with a 20hp pump already fixed on it. So, regardless of the head, flow or expenses. i need to run this pump using solar power.

thanks.

The guys are all saying it isn't impossible to run a pump but not practical from a cost basis. Not a solution I don't think.

[bcroe]

the simple question is how much electricity does a 20hp pump require. The simple 750W = 1hp would indicate that that about 15KW of power is required. Then with losses and in-efficiencies, you should plan on about 20KW of PV array being installed. That would provide power only in the peak sun hours of your site, maybe 3 hours a day. Batteries will be needed to increase that time, and even more panels installed to recharge the batteries.

A variable speed DC pump requiring 15KW could be run by an array like this, about 6.5 hours
a day under good sun at this time of year. It would require a matching mppt controller to
allow reduced power operation under mild overcast. While 15KW represents 20 hp, with losses
you might have more like half of that actually turning the shaft.

An AC pump is very fussy about power, so its not suitable for solar power as others explained.

Bruce Roe

[Sunking]

Don't feed the morons. 20 hp motor on solar. Now that is funny.