?Pond pump AC / Inverter? or DC pump?

[monkfarm]

I have a little experience with solar (6700 watt home solar on 4 racks), although I always used an installer for my home system. Now that I'm retired, and somewhat mechanically apt, and have less funds to spend; I need to do this myself. I have a large pond that needs water pumped from a nearby creek (15 foot head). I have an old Trace 1500 watt marine inverter that I am considering using with a standard AC pump because the AC pumps are so much cheaper, than the solar DC pumps. Is this a feasible plan because I need quite a bit of water?
I am already using a 12V dc bilge pump on a different smaller pond with one panel successfully. Is there a site that pot growers migrate to with people that have a lot of experience with irrigating and pumps? Or is that out of line for me to ask that question here, haha?
We need to address this, we have been using a gasoline pump (honda 8hp) in an environmentally sensitive area and we really want to stop doing this!

Thank you so much for any feedback!

[bcroe]

Solar power is quite variable, worse if you see clouds. Ac motors are not happy with this,
wanting to run at a constant speed or not at all. They also have starting surges that cause
an inverter setup to be less efficient/more expensive, and you really can't run a substantial
inverter without the massive cost of batteries.

DC motors with a control designed for solar panels avoid all these problems, running at
whatever power level is currently being generated. No batteries. Bruce Roe

[monkfarm]

Thank you, Bruce! That makes sense. The DC pumps I'm looking at cost almost 10 times what an ac pump cost, so I starting thinking of alternatives, especially since I already have the Trace Marine inverter.
Yeah, I don't really want to use batteries and a charge controller, I have two separate systems on the house, one with batteries (remote location, grid goes down at times), and tired of replacing batteries, and I'm not convinced the battery people have it together, yet.
Does anyone think the Dankoff pumps are worth the extra money? I know he's been at it for years, I met him a few times at the Midwest renewable energy fair.
Anyone else with any input on this, or other ideas about the pump?

[PNPmacnab]

Quite a bit of water covers a lot of ground. Sub hp single phase motors are inefficient and a 1500W inverter is pretty small. I need a 2,000 to start my fridge with surge. There are brushed AC transfer pumps that will operate on DC because they are a universal motor. I haven't done pumping but there seems to be a lot of choice out there.

[monkfarm]

Thank you for your reply, PNPmacnab! This is quite interesting. We inherited a large pond (est 100' X 150') when we bought this property in '94, and now we have thousands of frogs and toads being born in it, and ducks and geese come here, so we are trying to keep it going. The more water we are able to pump in there the better. I have two Trace 12V inverters I had in Trucks that I had for business, and so I thought perhaps I could use these to pump. I have a neighbor who used to work in an electrical shop who seems to be quite knowledgeable, and will fill me in on your response (universal motor??) I am open to educating myself in this effort. We are committed to finding a way to eventually pump all the water we need via solar.
Dean

[jflorey2]

I have a large pond that needs water pumped from a nearby creek (15 foot head). I have an old Trace 1500 watt marine inverter that I am considering using with a standard AC pump because the AC pumps are so much cheaper, than the solar DC pumps.

This is what solar direct pumps were made for. Get a small array, a current booster and a DC pump, and the pump will run whenever the sun is out.

Yes, AC pumps are much cheaper. But a solar direct pumping _system_ will end up being much cheaper than the solar array/charge controller/battery bank/inverter you will need to run an AC pump.

If you are really concerned about money get an RV water pump (cheap) and put in a good filter upstream of the pump. That will work for a while while you get experience and save up for a better pump.

[Sunking]

You do not need solar to pump water. No tech at all required. Use what every cattle rancher uses and is dirt cheap, never needs batteries, or power.

WINDMILLS.

[monkfarm]

Ha ha, Sunking, ya, I like those aeromotors. I have a 1938 model that pumps the water for the house. But the pond is down in a hollow. We are in hill country, west central wisconsin. It is quite a bit of work, those aeromotors. We just had to replace the leather, and some other stuff. I've been out there working on it in freezing rain trying to get our water running. Probably originally installed in 1938.

[monkfarm]

jflorey2,

As I stated in my original post, we have been pumping water using a single panel, and a bilge pump on our little pond. I did look up RV pumps, (have you used these on a 15ft head or more?) and it seems like they are not good for the 15 foot head, and the 40 foot run from the creek to the pond. Also, they are used for fairly clean water, and I could run it through a filter, but I would rather have a pump that is tolerant of dirty creek water. If you actually have experience with these with something other than an RV, and still think that this is appropriate, please tell me all about it.
The bilge pump we have been using for about 10 years on the little pond seems to work well for the small amount of water that it pumps, but I would need something larger.

[bcroe]

How about a paddle wheel in the creek? Run an Archimedes screw to raise some water.
Bruce Roe

[jflorey2]

As I stated in my original post, we have been pumping water using a single panel, and a bilge pump on our little pond. I did look up RV pumps, (have you used these on a 15ft head or more?) and it seems like they are not good for the 15 foot head, and the 40 foot run from the creek to the pond. Also, they are used for fairly clean water, and I could run it through a filter, but I would rather have a pump that is tolerant of dirty creek water. If you actually have experience with these with something other than an RV, and still think that this is appropriate, please tell me all about it.

I used a food-grade centrifugal pump, and then later an RV pump, for about 5 years to move graywater (which is pretty dirty although perhaps not as 'gritty' as creek water.) I used a simple screen filter before it, and would clean the screen filter about once a month. Both worked OK. The RV pump, since it would self-prime, was a lot more convenient - but that has to do with where you are placing the pump.

The bilge pump we have been using for about 10 years on the little pond seems to work well for the small amount of water that it pumps, but I would need something larger.

Plenty of larger bilge pumps out there.

[jflorey2]

How about a paddle wheel in the creek? Run an Archimedes screw to raise some water.

Easier yet, use a hydraulic ram pump. They are available off the shelf and are pretty cheap ($165 or so for a 3/4 inch pipe model.)

[bcroe]

Easier yet, use a hydraulic ram pump. They are available off the shelf and are pretty cheap ($165 or so for a 3/4 inch pipe model.)

I did not think that would work without some head pressure (build a dam). A paddle wheel just dipped into
the water below could do some work. Bruce Roe

[jflorey2]

I did not think that would work without some head pressure (build a dam).

Agreed. But an off-the-shelf ram will give you 10:1 lift - and that means you'd only need a 1.5 foot head.

[monkfarm]

Pretty slow moving stream, I can't get too elaborate with a setup mounted in the creek. The DNR would probably be upset. I have thought of this, the ram pump, I love the idea, but I really need something larger to replace the gasoline pump. I may have to bite the bullet and get a DC Dankoff pump or similiar. I will check out the ram pump and see how fast the current has to be.
I really appreciate all the ideas, thank you!