Installing Off-Site Watering Setup

[OregonSolar]

Hello all, this is my first post to this solar forum!

I was wondering if all you wonderful folks here could give me some advice on some off-site stock watering systems I'm going to be installing next year. I've already planned this out; so here's my plan:
The solar panel will be a 180-190 watt 24V panel; I'm not sure as of yet on which panel to buy since my usual carrier (SunElec) doesn't carry a 180 watt panel anymore, I may hook two 80/90 watt panels in parallel but that is undesirable for weight/bulk reasons.
It will have two 75Ah backup batteries (http://www.northerntool.com/shop/too...8001_200338001) linked in series for 24v, with a Instapark PRS-1515 (http://www.amazon.com/Instapark%C2%A.../dp/B00B138XRC) charge controller.
The pump will be a Shurflo 2088-474-144 24V pump (http://www.amazon.com/SHURflo-2088-4.../dp/B002MWFFVS). There WILL be a filter on it, I know from experience drawing water from a stream without a filter is inviting bad luck.

The entire solar panel/battery/controller will be mounted on one pole. The batteries and the charge controller will be in a vented box mounted on the pole as they are being installed in a flood area; a 12 gauge solid Romex wire will be used for all wiring, although I may use a 10 gauge to the pump depending on how long the run is to the pump itself.

So, what do you think?

[Naptown]

Romex is not suitable for exterior applications use type UF
Without knowing location and run time it can't be said if it will work or not.

Lastly why don't the cows go directly to the stream

[OregonSolar]

Romex is not suitable for exterior applications use type UF
Without knowing location and run time it can't be said if it will work or not.

Lastly why don't the cows go directly to the stream

Thanks for your input.

With that in mind, I may put the romex in conduit or just get some standard wire. But the sizing is OK, right?

The most likely location (as it will vary) will be on the north side of a streambank with appx. 8+ hrs of full sun in the summer. Latitude is 42 degrees. The system(s) will not be used in the winter, they will be disconnected and the pumps removed.

The system will need to supply about 2500 gallons of water per day (75 cows estimated herd size x 30 gallons/day per cow = 2250, not counting for tank leakage/evap/increased usage in hot weather), which the pump can easily handle at 3 gallons per minute, which is 4320 gallons per day. The batteries are simply insurance for cloudy days; it is doubtful the system will actually run at night. Considering the pump will need to run for 12 hrs to supply enough water, I may need a slightly bigger panel (200W) to keep the batteries up while the pump is running.

The system will use the on-demand feature of the pump; a float will shut off the flow of water when the tank is full, causing the pressure in the pump to increase triggering the pressure switch. A small accumulator at the pump will help prevent rapid cycling due to minor leakage.

The whole point of the off-site watering system is to keep the cows off the stream to protect the riparian area for environmental conservation. If you don't know what this is consider wikipedia: https://en.wikipedia.org/wiki/Riparian_zone

[Mike90250]

why don't the cows go directly to the stream

Problem is, they go directly in the stream.

[OregonSolar]

Problem is, they go directly in the stream.

Funny, and true, but not helpful. Obviously the greatest damage they cause to the riparian area is just plain trampling. Trust me, I wouldn't worry about a few cows deciding the river is a bathroom when you've seen some of the things that get 'accidentally' dumped in there

[Naptown]

Then go to the off grid battery design stickie and do the calculator there.
I will point out that 8 hours anywhere in North America isn't happening.
Since this is more of a summer thing use the month it will operate that has the lowest insolation when operating
Cut battery size in half perhaps depending on what you need for a charge rate.
Or just post the spreadsheet for comment

[OregonSolar]

Then go to the off grid battery design stickie and do the calculator there.
I will point out that 8 hours anywhere in North America isn't happening.
Since this is more of a summer thing use the month it will operate that has the lowest insolation when operating
Cut battery size in half perhaps depending on what you need for a charge rate.
Or just post the spreadsheet for comment

Woah woah woah!!! I used the calculator and that REALLY doesn't sound right. A 750Ah battery bank and a 1KW solar array just to run a little 200 watt pump for 12hrs? What doesn't add up here? Even if I put the inverter efficiency at 1 because there is no inverter, that's still 800 watts of panels! This is something wrong here...

[Naptown]

2 things
That does not take into account for daytime running only
Did you put your local insolation in correctly for the months it will be in use.
Oregon on the coast can be pretty cloudy.

[OregonSolar]

2 things
That does not take into account for daytime running only
Did you put your local insolation in correctly for the months it will be in use.
Oregon on the coast can be pretty cloudy.

Yes I did. I am not on the coast, I'm about 150 miles inland, and our summers are CLOUDLESS, period, minus our average 2 thunderstorms a year. Assuming our average summer insolation is 6 hrs, and the pump needs to run 12hrs a day to supply enough water for 75 cows at 8 amps, it still says a 570 watt solar array and a 475Ah battery bank at 24V. That is outrageous! There is NO WAY IN H3LL my contractor is going to pay that much for 10 off-site water systems with those specs. Nor does it sound necessary, and that much equipment sitting in a field is crazy. Is there something I'm doing wrong here?

EDIT: That is also at 20% DOD. If I could get away with 35% how much would it affect the numbers?

[SunEagle]

Yes I did. I am not on the coast, I'm about 150 miles inland, and our summers are CLOUDLESS, period, minus our average 2 thunderstorms a year. Assuming our average summer insolation is 6 hrs, and the pump needs to run 12hrs a day to supply enough water for 75 cows at 8 amps, it still says a 570 watt solar array and a 475Ah battery bank at 24V. That is outrageous! There is NO WAY IN H3LL my contractor is going to pay that much for 10 off-site water systems with those specs. Nor does it sound necessary, and that much equipment sitting in a field is crazy. Is there something I'm doing wrong here?

EDIT: That is also at 20% DOD. If I could get away with 35% how much would it affect the numbers?

If you discharge your battery more than 20% you run the risk of weakening it and then require replacing it sooner. Same goes for a smaller pv panel system. If you don't have enough solar watts to charge the battery you will end up shortening its life and have to replace it sooner. The battery is an expensive item and replacing it before a normal lifetime will be costly.

It is sort of a pay me now or pay me later.

[OregonSolar]

If you discharge your battery more than 20% you run the risk of weakening it and then require replacing it sooner. Same goes for a smaller pv panel system. If you don't have enough solar watts to charge the battery you will end up shortening its life and have to replace it sooner. The battery is an expensive item and replacing it before a normal lifetime will be costly.

It is sort of a pay me now or pay me later.

So no matter what I do, I actually need this amount of panels and batteries.

So much for my contract.... I was basing it off of a $500-600 dollar a piece system with a 250 watt panel and about a 100Ah battery. This really throws it all for a loop.

[Naptown]

No way you are going to do this for $500
Well you could but they will probably fail.

[Naptown]

So no matter what I do, I actually need this amount of panels and batteries.

So much for my contract.... I was basing it off of a $500-600 dollar a piece system with a 250 watt panel and about a 100Ah battery. This really throws it all for a loop.

If it makes you feel any better you fall into the 98% of folks who undersize their systems as they did not allow for enough solar or battery etc to make it viable.
Not picking on you it's the laws of physics that cannot be broken.

[SunEagle]

No way you are going to do this for $500
Well you could but they will probably fail.

Well sure he can do it for $500 each. Then in a year do it again and then again and then ....

[OregonSolar]

If it makes you feel any better you fall into the 98% of folks who undersize their systems as they did not allow for enough solar or battery etc to make it viable.
Not picking on you it's the laws of physics that cannot be broken.

Ok, well if I scrap the battery I 'may' be able to get it to work, but only 'maybe'. 648 gallons a day isn't enough for 75 cows, only 20 cows if you push it.

I may just have to eat it, suck it up to the boss and get a punch in the face. Oh well, so goes life.