Trying to set up a solar charged, battery operated pump

[Cliffh]

I've got a small (<1/4 acre) pond on the property.  To aerate and keep a little water movement I've been running an extension cord from the shop to the pond to run a 1/2hp sump pump.  I'd set the pump in a container, with a timer to run it a couple times per day for 15min or so.  Off the pump is a vertical 1 1/2" pipe with a 45* elbow at the top.  This has worked OK, with a few exceptions:

I have to dig back into the bank, by hand.

It's cost me more than one good extension cord.

An extension cord is not a good solution for the power supply.

This year, I'd like to try something different.  I'd like to setup a 12v battery with a solar charger and attach a self-priming 12v pump to the battery.  The pump I'm currently looking at has 3/4" garden hose fittings for the inlet & outlet.  Pushing the water through a garden hose instead of a 1 1/2" pipe will require running it for more than 15 minutes at a time, or more times per day.  That'll depend on how the water's looking after a few days.  The mount for the outlet will be easier to rig, and there is a good variety of nozzles to get an acceptable spray pattern.

Looking at HF, I've come up with these items:

https://www.harborfreight.com/25-watt-solar-panel-63940.html
https://www.harborfreight.com/12v-35-ah-sealed-lead-acid-battery-56770.html
https://www.harborfreight.com/7-amp-solar-charge-regulator-96728.html
https://www.harborfreight.com/12v-dc-transfer-pump-290-gph-63324.html

Still have to source a 12v timer.

I've got a few questions, and probably more that I don't know to ask:

How do I compute the run time for the pump without draining the battery too far?  Down to a point where the solar panel can't get it back up to full charge before the pump comes on again.  How long will it take the solar panel to charge the battery?  Is that enough battery?  Would a deep cycle battery be necessary?

I could use a convertor and run a 120v pump. 

The pump description says it's self-priming, but I think I'll be putting a check valve inline.

[Brad Johnson]

First thing that stands out is pump drawing 50 watts but solar panel is 25w max. Unless you're commited to less than an hour or two of total run time per day, you'll never be able to keep the battery charged.

For a 50w load plus efficiency, transmission, and controller losses you're gonna want a 100w panel, minimum. 200w is preferred unless you plan on having some type of motorized tracker to optimize panel exposure.

For what you'll have in panel, pump, and controller, you could run DB cable and mount a weather-rated box on a post or pole right at point of use.

Brad

[Kingcreek]

Are you committed to solar electric?
My neighbor aerates his pond with a windmill pump. Seems to work very well.

[AZRedhawk44]

First thing I note is that you were previously running a 1/2 hp pump.  One horsepower is equivalent to approximately 700 or 750 watts.  The old pump is about 350ish watts.  Your replacement pump is only 50 watts.  It's going to need to run a lot longer in order to cycle as much water.  This also corresponds with your pipe/hose diameter where 1.5" will move considerably more water than 0.75" pipe.  0.75" has a surface area of 1.77" while 1.5" has a surface area of 7.06".  It's about 4x the capacity (go figure... double the radius and you get 4x the capacity).

You need to run this pump 6-8x as much to effect the same water movement.

The battery you linked claims to have 35Ah of usable power.  12v @ 35Ah yields about 420 watts usable storage, but I'm skeptical you will get a full 35Ah out of it and have the battery remain usable for long.  Your pump sucks 50 watts so in theory this battery could run it for 8 hours, but that would be abusive to the battery.

I'd suggest a 25-50% duty cycle through the day as long as you have sunlight, and to get a 100 watt panel since it will only get 100 watts at peak sun position, and you'll probably only get 10-20 watts charge rate for the hours nearest sunrise and sunset.  Overcast conditions will weaken the charge rate further.

[Cliffh]

The system doesn't have to be solar powered.  I am trying to avoid digging a 60ish foot ditch, but looking around at solar options I'm not coming up with anything practical.  If I do break down & rent a ditch witch my options open up dramatically with 120v stuff.

And the 120v options seem to be much less expensive than the wind powered options a quick search found.  They seem to be starting around the $800 mark.  A 100' roll of 10/2  is a lot cheaper, and would put power out there that DW has been asking for.

Now to work in the time around "The List" and doctor appointments....

[cordex]

I’ve been thinking about the same thing. What I would love is a big floating solar panel that powers an air pump and pipes it through bubbler stones.

I might just have to run 120v like you are planning.

[Cliffh]

I'd like to hear about it if you come up with a workable solution.

[230RN]

How long is the extension cord at present?

[JTHunter]

Cliffh - here's an idea for you.
I bought this house almost 20 years ago.  On the back half was a 30' x 50' pole barn that had no power and it is about 100' behind the house.  We arranged for a friend who was an electrical contractor to help me out and we started by upgrading the house from 100A service to 200A and diverting 60A to the barn and re-routing the feed to the breakers which had (incorrectly) gone through the attic.  He brought the feed through the crawl space to keep the line cooler.
In going to the barn, he used his Vermeer to dig a 3-5' trench that we put a layer of sand on the bottom to create some cushioning for the 2 PVC pipes.  One was for the two 4 gauge power cables and a second thinner pipe for the phone line.  This was dug from the back of the house, diagonally under the gravel driveway, then alongside it to the side of the barn.  After he set up the 100A junction box in the barn, I wired the rest of the barn myself, putting in a small electric furnace, multiple lines for lights, outlets, and assorted power tools.  There is one dedicated line for the large freezer out in that barn as well.

You won't need as "extensive" a project but I still suggest going down at least 2' or more, partly depending on how deep your "frost line" is located.  Deeper is also safer if somebody starts digging or driving over the line.  Run at least a 10 gauge line out there and put a "weatherproof" outlet box on the PVC where it comes up out of the ground.  This way, you just plug your pump into the outlet.  Should the pump ever fail, unplug and replace it.
Good luck!

[Cliffh]

I've been using a 75' extension cord, but there are a few coils laying on the ground by the time it gets to the pump.  Haven't measured the distance but I'm guesstimating 60' would be about right.

JTHunter:
The shed/workshop (a cramped 20' x 20') has a power supply/meter separate from the house.   My plan was pretty much what you described with the exception of putting sand in the bottom of the ditch, hadn't thought of that, makes sense though.  Digging the ditch deep enough was the reason I mentioned the ditch witch - this boy's dug enough deep holes by hand and don't want to do any more.  Let the machines do the work.

IIRC, the frost line's 18" around here.  Figured to put it deeper 'cause it'll cross the power co. easement, and they've recently been driving some larger trucks across that area - running fiber optic cable.  YEAH!  Fiber optic internet is in my near future!

I've got more wiring to do in the shop, more lighting & 120v outlets.  It'll come, all in good time.

[JTHunter]

Sounds good.  At 60-75', you might be able to get by with 12/3 solid wire but for the sake or redundancy, you might still be better off with the 10 gauge.
One of the problems we had with Vermeer was that we had to cut through some tree roots.  The roots won.  Contractor had to get his larger Vermeer to get through the roots.
If you can find it, the type of non-metallic cable designed for underground without a conduit might be easier to use.  We laid the cable and phone lines out on the ground first then slid the 10' sections of PVC pipe onto them.  Then we glued the PVC together before putting it in the trench with excess wire hanging out of both ends for later hook ups.

Good luck with your project. 

[cordex]

I’ve got 150 feet at least. Unless I reuse the cables running to the disused well pump, which would only save me maybe 25 feet.

I keep waffling between a fountain and a bubbler system. I’m not sure that the cost or complexity would be that different between the two.

[JTHunter]

A fountain will cause a greater amount of evaporation than a bubbler.  Depending on the shallowness of the water, the impeller for the fountain could also kick up some silt from the bottom and jam the pump.
A bubbler doesn't move as much water but aerates it at the same time.  They can also be prone to clogging, depending on how the piping is arranged.

[230RN]

Sounds good.  At 60-75', you might be able to get by with 12/3 solid wire but for the sake or redundancy, you might still be better off with the 10 gauge.

That's where I was headed with my question, but 75 feet of extension means 150 feet of conductors (besides the ground line), regardless of the distance to the pond.

[Ben]

I’ve got 150 feet at least. Unless I reuse the cables running to the disused well pump, which would only save me maybe 25 feet.

I keep waffling between a fountain and a bubbler system. I’m not sure that the cost or complexity would be that different between the two.

My recommendation is absolutely an aerator vs a fountain. Over my first two years here, the combination of aerator, demucker, and algae packets completely rehabilitated my 1 acre pond. It was a cow infested hole when I got here, and now, outside of algae bloom season, you can easily see fish a foot down. The previous owners had a fountain, and it seemed to do nothing.

It's not the cheapest, and only the smallest of the units, like the 40 or 20, would be solar compatible unless you went big with the solar, but the Hi Blows rock.

https://www.amazon.com/HIBLOW-HP-80-Aerator-Septic-Linear/dp/B006YGDBWI

I have the 80 on grid power and a timer, plus make seasonal changes between Winter and the rest of the seasons. The Hi Blows were originally septic aerators, but were discovered by the pond community. The design for septic makes them unstoppable beasts. Mine has been running every day for five years.


Edit: Depending on pond size there are also these:

https://www.amazon.com/gp/product/B09PMNYQNR

I made a small (about 50' x 25') habitat pond on the other side of the property, and two of them handle keeping the water clear and give plenty of air to the amphibians. It probably wouldn't be hard for an APS rednecker to make something similar with more power out of whatever parts.

[cordex]

Thanks for the recommendations, Ben.  The HiBlow looks like a good solution if I can get 120V (either hardwired or via an inverter) out there.

[Cliffh]

The power line run from the meter to the shop is a combination of going through PVC & direct bury - DB cable was used throughout the run.  Mainly used the PVC to enter & exit the ground, once it was in the bottom of the ditch it was just laid in the dirt.

I've already bought enough PVC to make the run.  I'd thought of putting the PVC just below grade and running an extension cord through it.  If I'm going to do that, might as well do it right.  I'll probably hit a few tree roots on the way, there's an old oak & a fairly large willow on either side of where the receptacle will end up.  May end up digging what I can with the machine, finish up with a saw and shovel.  Only time will tell.

I've had good experience with Hiblow pumps too.  Ours is used on an aerobic septic system, runs 24/7/365.  I don't know how long the original pump was in use, it failed sometime during the first 3 years we were here.  I bought a used* Hiblow to replace it, must be over 12 1/2 years by now, it's only required filter changes.   

Still have the old one in the shop.  Might have to take it apart and see what it needs, last I looked there were a lot of different part kits available.

*No idea of how "used" the replacement was. 

[Ben]

Still have the old one in the shop.  Might have to take it apart and see what it needs, last I looked there were a lot of different part kits available.

I have the Hiblow rebuild kit sitting in the shop for just in case. I think it was like 50 bucks on the amazons.

[Cliffh]

It's been years, probably a decade or so, since I last looked at part kits for it.  At that time, they were running a lot more than that.  If they're down that low, I'll have to grab the model number and do some shopping.

[Ben]

I bought it a couple of years ago, so it might be higher now.

[Cliffh]

The prices I recall were north of $150, so a bit over $50 wouldn't be bad.

[230RN]

If I'm understanding things, using an aerator with a pump in the building, and running the air out to the pond in sprinkler tubing* or the like would be cheaper and simpler and more reliable than running wiring out to a local pump... either air or water --out by the pond itself.

This, regardless of whether the pond is 15 feet or 150 feet away from the building.

? ? ?

Terry, 230RN

* Or whatever, even garden hose.

[Ben]

If I'm understanding things, using an aerator with a pump in the building, and running air out to the pond in sprinkler tubing or the like would be pretty cheaper and simpler than running wiring out to a local pump... either air or water --out by the pond itself.

? ? ?

Terry, 230RN

The aerator doesn't need to be inside. Mine sits next to my pond with a simple rain cover. There's a limit to how much air hose you can run with an aerator, based on the unit's output as well as water depth. I run around 100' of weighted hose, split into two bubblers.

[230RN]

The aerator doesn't need to be inside. Mine sits next to my pond with a simple rain cover. There's a limit to how much air hose you can run with an aerator, based on the unit's output as well as water depth. I run around 100' of weighted hose, split into two bubblers.

I think 15 PSIG will get you down to 30 feet depth, and the distance for the air hose is the same problem as the distance with electricity.  Longer distance, thicker wires. Longer distance, bigger piping.  And you don't have electricity running outdoors without a permit... assuming one was required, rain cover notwithstanding.

Anyhow, what's best is best, I just thought keeping the pump in or near the building and running piping or sprinkler tubing out there might be simpler and safer, although you might need a bigger compressor to compensate for pressure loss in the piping (transit head loss).  And there's the noise factor by the house, too.

I'm not married to the idea, hence the " ? ? ?."

Terry, 230RN

[Cliffh]

As far as the noise level, those Hiblows are quiet.  Ours is outside, just on the other side of the bedroom wall that my head is nearest - can't hear a thing.  Can barely hear it standing 5' away outside.

The rest of it, well, I'll have to ruminate on it for a while.  Off the top of my head, there's not a lot of room in my shop.  And would still have to run PVC or similar piping.

There are advantages to not running electricity out there, price being one.  Then again, SWMBO has wanted electricity in that area pretty much since we moved in 15 yrs ago.