What solar setup to power a 750 watt water pump for 2 hours per week

Finding it really difficult to get my head around this whole solar panel thing. Basically i need to pump water from a spring 50 meters up a hill to my house and fill a 2000 litre water tank. Ive worked out with the 750watt pump i have will have to run for about 2 hours per week to fill the tank which will give me the water i need for the week.
What solar setup would i need and at what cost? as i really need to do this the cheapest way possible. Wind power could also be an option if cheaper.

http://permaital.blogspot.it/

If you get a 850 watt solar system that directly powers you pump you will be good, the only problem will be to make it turn off when the tank is full.

You could just go down to the well on a sunny day twice a week and turn it on for an hour and then turn it back off.

Solar panels cost around $1 per watt so that around $800. Each panel is around 29v.
So if you wire 4 of them in series you should get close to 120v .
Most motor/pump are not too strict on voltage so all you will need is (1)solar panel, (2)wire, (3)switch, (4)pump and (5)something dark to cover the solar panel or a load.
Obviously you are going to need a roof "thingy" to install the solar panels on.

You could also go with a more advance setup with a solar panels, controller, charger, battery, inverter, load, pump and of course wires. Such a setup would allow you to buy a smaller solar cell 200W vs 800W, however in trying to save $500 in panels you will spend $2000+ more in the extra parts, unless you already have them laying around or something.

Here is a quick search on amazon look around you can get it alot cheaper.
http://www.amazon.com/Four-RENOGY-Solar-Panel-Photovoltaic/dp/B009ZOJ14S/ref=sr_1_1?s=lawn-garden&ie=UTF8&qid=1358201791&sr=1-1&keywords=250w

Thanks Bengi. great help, would like to go cheaper though but then i would think you do get what you pay for with solar panels.

An 850-Watt solar system could probably power a significant portion of your household power needs. Why not just get a smaller pump and run it more often? Maybe even continuously when the sun is up?

Just off the top of my head, you would need 80-100 W, or one panel, tied to a 70+ PSI, 24VDC, 10 GPH+ pump. This would be along the lines of a booster pump for a reverse osmosis unit, like a Shurflo 85-120. One panel would be about $100 and maybe $150 for the pump. No regulator would be needed; these pumps are pretty robust.

Then again, you never actually said what your water consumption was, just that your current pump runs 2 hours per week. It is possible that the Shurflow 85 is too big, in which case when your tank was full you could just let it overflow.

very good point Dave ,i should have thought of that, i could run a less powerful pump,and i could say pump for 6 hours per day, my only concern would be if it could cope with pumping 50 meters up hill.
My water requirements are 2000 litres per week so i roughly worked out it would take 2 hours of running the pump per week.

Right now I live entirely on the grid and I use about 100KW per month in the summer. So the system that I described to you could power my need all spring ,summer and fall. except for a few winter month due to less sunlight hours.

The system that dave stated would be alot cheaper
A few question. Whats the difference in Height between bottom of well to top of water tank.

50 meters of fresh water is 71 psig. An 80 psi positive displacement pump is more than enough. The thing that would be difficult to wrap your head around is that when it was running, you would see no more than a trickle of water...

I would have to see the specific design specs of the pump to see how long you could expect it to last, though.

Bengi,yeah obviously if i had this set up you described it could also be used to power other appliances in the house. I need to calculate the KW i would need as you have done. Really desperate to get off the grid here for water and elec its just the money i need to spend to do it. I know people that have spent 10,000 dollars on systems that is going to take them something like 20 years to break even on. Its like we are not given a really affordable and reliable alternative to power our homes. As i say i am still trying to get my head around all of this.
My spring is coming out of rocks in the ground where i have dug and lined a large hole that fills up with the water. The pump i have is of the portable submersible kind ,its 50 meters distance from the hole to the top of the tank. Dave, the pump you describe is kind of new ground for me , going to have to do more research in pumps i think, can these be portable?

Dave, would this do the job: http://www.isopurewater.com/Shurflo-8010-102-210-8000-Series-RO-Booster-Pump--100-GPD-24V-38-FPT-80-PSI-Bypass_p_2751.html

Might sound like a stupid question but would this come with a plug?

You mean to plug it in?

These pumps come with a 120 or 240VAC - to - 24VDC "transformer" (actually a transformer/rectifier/filter, but that's semantics). You can also just feed them 24VDC straight from a solar panel. They are designed to operate continuously, at high pressure, which is why I thought it would be a solution to your engineering problem.

They are as portable as you need them to be.... I would think that you would simple drive a 4x4 post into the ground near the spring, put the panel on it, bolt the pump to the post, and weather-proof it with a 5-gallon bucket or something. Have the suction hose going into the spring and the outlet hose connected to your current pipework.

I have been doing a lot of research today on this type of pump and system you have talked about and i have got to say its seems perfect for what i need. Anyway just wanted to thank you again for your advice ,this has really cleared a lot of things up. So with this pump i will attach direct to a 150 watt solar panel just to make sure and i should be pumping water pretty cheaply. will setup as you advised although my spring is very much in the shade so the panel will be further up the hill in the sun and a long cable from panel to pump will be needed. Fantastic and thanks again.

Make sure that the solar panel is giving off 24V, some do 6V, 12V, 24V, 29V, 37V.
You could wire 2x12V or 4x6V in series, but that is just complicating your life.
Keep the pump close to the solar panel use a longer hose if you have.
The long the cable running DC current the greater the power loss, so play around with the setup location once you get the parts.
Please post some pics once you get the parts and such.

Thanks Bengi for all the advice, Yeah think i will have to play around with it a bit. If this works its going to make big savings to my outgoing costs. Yeah will certainly post some pics when setup,thanks.

Ah, a few last things. Looking at the spring again today i realised there will not be enough sun until at least 25 meters above it. So i think my options are either:

1. taking down a lot of trees that are blocking the sun to the panel (don't really want to have to do).

2.Having the pump and panel 25 meters above the spring. that would mean the suction pipe from pump to spring would be 25 meters long, not a problem but does this pump have the suction power and would it also mean i could have 25 meter suction and another 50 meters of pushing water up from the other side of the pump ??

3.Having the pump just above the spring and a long cable running from the panel direct 25 meters above. but as Bengi explained -the longer the DC cable the more power i will lose. So would my options with this be having say 250 watts of panels DC to give the extra power lost in the long cable? or having the 100-150 watt panel wired though a charger/battery/inverter converting it to AC so i could run a normal AC extension cable 25 meters pump/spring to panel and not lose any power??

So nearly there with this ,hope you guys can help

You would lose power at every conversion.
Charger loss, battery loss, inverter loss, transformer loss. each step would be at least 10% so it is still a 50% loss.
SO whats the best solution. get the pump and in your kitchen plug it in then try and suction some water with a hose in a bucket 50 feet away if it works then no need to worry. If it does not work then you have to cut down some tree and replant the area that you cut down with some berry/herb plants. So if your solar panel is 11ft tall then you could have pretty much dwarf fruit/nut/berry plant.
Like this 5-8ft mulberry tree http://www.onegreenworld.com//product_info.php?cPath=1_41&products_id=674

Unfortunately no pump in existence can have a suction more than 10 meters up; at this suction pressure the water will flash to steam and the pump will vapor lock.

There really isn't a problem with having the panel 25m up the hill, though. I would recommend a panel rated at 29v. In most cases it will produce power at a lower voltage than its rating and DC pumps work better at higher voltage, but tend to burn up at lower voltage. You then just use a slightly larger cable to account for wire losses, or use more wattage.

Have you thought about a ram pump? If you can pipe the water downstream from your spring to a ram pump, you can then pump it uphill to a storage tank. How much volume depends on your differences in elevation and length of downstream pipe.

engineer775 on youtube has some very good videos on it.

You build the pump yourself out of common pipe parts and it uses no power.

Thanks Dave for all your advice, Finally made the order and should have everything up and running within the next three weeks. Bengi ,thanks for the link on mulberrys. certainly will be planting out a few in the coming years although i think i can save the trees giving me the shade problem for now by running the longer cables on a 250 watt 29 v direct to pump,i will gain another 5-8 meters with the suction pipe. Glenn ,the ram pump i have looked into but i would not have enough drop off from the spring which is a shame as this would really be the cheapest and easiest way to pump water.

alex jackson wrote:Thanks Dave for all your advice, Finally made the order and should have everything up and running within the next three weeks. Bengi ,thanks for the link on mulberrys. certainly will be planting out a few in the coming years although i think i can save the trees giving me the shade problem for now by running the longer cables on a 250 watt 29 v direct to pump,i will gain another 5-8 meters with the suction pipe. Glenn ,the ram pump i have looked into but i would not have enough drop off from the spring which is a shame as this would really be the cheapest and easiest way to pump water.

I think I musta missed the part where you mentioned the power input of the pump?

Alex,

I'm coming a little late to the party, but perhaps I can help (I own a solar installation company and have set up a number of PV-direct water pumps). First, I want to be sure we aren't talking Apples and Peaches here... You wrote:

alex jackson wrote:Finding it really difficult to get my head around this whole solar panel thing. Basically i need to pump water from a spring 50 meters up a hill to my house and fill a 2000 litre water tank.

http://permaital.blogspot.it/

OK, we need to be sure about the vertical lift required (distance straight up), vs the horizontal distance. Is it 50 meters from the spring to the house along an uphill slope, or is the house actually 50 meters (164 ft) higher in elevation than the spring? This is an absolutely critical difference. The vertical height, or lift requirement matters a LOT, while the horizontal distance would have to be pretty large to matter very much. This also applies to the questions of shading, tree removal, and pump placement. As an example, you could go up 25 meters to place the solar panel and be maybe 250 meters away, which would make a small difference is pump friction losses, but would make a huge difference in wire size and expense if you were sending solar power to a pump down at the spring.

BTW: pumps push a lot better than they pull (or "blow" better than they "suck", as it were), so if you had to mount a solar panel 25 meters away from the spring, I would still put the pump right at the spring, and figure out the correct wire size to offset voltage drop.

I may not have read carefully enough, but someone else asked for clarification, and I didn't see the lift requirement clarified. I'll be happy to help if I can.

Thanks Brad for helping out, yeah the 50 meters from spring to house is a gentle terraced uphill slope, around a 35 gradient. So at the moment my plan is to have the solar where i can get sun,25-30 meters above the spring and pump. I am going for a 250 watt 29v.The pump runs on between 100-150watt 24v .Hoping this will give the pump enough power. Could you help me with wire size? what would i need for the job? is it possible the right sized wire can make this possible or would i have to go more watts with the panel ?
The lift requirement ,if that's the distance from pump to tank is around 50 meter.

I'm glad Brad stepped in here. You definitely need to consider the actual lift requirement. You also mentioned that your spring feeds a hole that you dug. How quickly does the spring fill the hole and what are the chances of the hole being emptied too quickly by the pump? (No water = burned out pump!) You might need a float switch to cycle the pump on/off based on the water supply. And if that were the case, I'd probably put a couple of batteries (two 12v in series) down there by the pump.

All this as you can see is all very new to me and my now understanding is the lift is the distance is from the pushing side of the pump to where you want your water to come out. So Brad has helped me to understand that the gradient of the pipe plays an important part to the distance the water can be pushed (i think). If the pipe is vertical its not going to pump to as much distance as if it was horizontal . What i need to know is if my pump is 90psi which means it has around a 60 meter lift, is this distance the distance only when horizontal so my distance of 50 meter on a 35 degree gradient would be considerably less ??

As for the spring, it probably disperses 60 litre per hour and the pump would take 38 litre per hour, if i've got my head around this correctly.

I sort of figured it was not 50 meters STRAIGHT UP, so I suggested a pump that would produce the head for a worst-case scenario. If it is only 20m of lift than even better, the pump will require less wattage to work.

If the spring has enough water to cover a 1-horsepower lift pump for 2 hours, then it will cover this little 80-Watt pump easily.

I think the setup Dave suggested would be a very good choice -- as long as slow and steady will work well for your water demands. That way you'd move water to your cistern whenever there was both water and sunlight available, and with gravity you can use it whenever you need it.

The slope has been described as "gentle" and elsewhere as a 35% slope (or is that 35 degrees?)...I'm not sure 35 degrees would count as gentle (at least if I was climbing a long slope on a hot day!) A 35 degree slope is like an 8/12 roof pitch (a little steeper, actually); for every 12" forward, you have to climb 8" upward, or for every 1 meter ahead, you'd have to step up ~67 - 70 cm. If 35 degrees is the case, then 50 meters forward, would equal about 33-35 meters straight up, so the lift would be around 110'

Other things to consider, or just good info to record here for others seeking solar pumping options (some already stated above):

> a solar direct (or PV-direct) pump only moves water when there is daylight available -- cloudy = slower, and bright sun = faster. These pumps can tollerate the higher voltages produced by solar panels -- for example, a "12 Volt" PV-direct pump can usually take up to 20 or 21 volts input from the solar panels, while a 12 volt battery-based pump might only work from about 10 volts to about 15 volts.
> Some are low-cost, and some cost $ thousand$
> Lift and flow requirements determine how much OOMPH you need, and how much money you'll need to spend.
> There are very good PV-direct pumps that don't need batteries, and some have pretty advanced controllers with MPPT tracking (solar nerd speak for higher efficiency), and even linear current boosters (more solar nerd stuff, but a good option), while some just hook directly to the wires from the solar panel(s).
> A battery-mediated pump allows you to turn the pump on and off if the need for water is sporadic, or if you need to pump water when there may be no sunlight available.
> Submersible slow-start pumps are mounted under water an push the water up -- these are fairly expensive, but there are very good ones that last for many years (like Grundfos). Some are AC and some are DC.
> Submersible diaphragm pumps, like the SureFlo 9300, work well, but require routine maintenance (clean & replace screens, etc...)
> Controls: If you have a water tank you want to fill -- especially one at some distance from the pump -- you do not usually need to run wires all the way to and from the tank to turn the pump on and off. A float valve can be attached to the end of the hose or pipe up at the tank, and when the tank is full, that closes off the end of the pipe. The pump doesn't know this, so it keeps pumping, and the pressure in the water line rises... A pressure-activated switch can then cut off the power to the pump (from a battery, a solar panel, or even an inverter or the grid). In this way, the only long and expensive thing is the water pipe, and the electronics are all right near the pump and solar equipment. I have a Shurflo 9300 pump run by two 80-watt solar panels that pump water some 1700 feet (lift is only about 60') to a series of large tanks (about 1200 gallons total). The tank end has a float switch, and the pump end has a pressure switch. Pump and switch are in a little pump house that looks like a large dog house, with the panels on the roof.
> Solar panels charging batteries usually need a charge controller, and these can be simple and cheap, or pretty darned expensive.
> An inverter is only needed when you need AC power.
> Solar panels tend to change a little in voltage with changes in temperature (colder = higher voltage, and hotter = lower), but change in amperage with brightness of the light (all other things being equal).
> When you get info/prices/designs from many solar professionals, some may use the term solar "module" to mean what most people would call a solar "panel".... which can be confusing. In solar geek-speek, a number of solar cells make up each framed solar "module", and a number of solar modules in an array make up a solar "panel".... Most people still call 'em solar panels, but in case it comes up...
> ALL solar panels work best with ABSOLUTELY NO shading. SOME solar panels with an amorphous or "thin film" design will tolerate shade better, but all will produce more power in direct sun with no shading. For monocrystalline or polycrystalline solar modules, shading is a really really big deal -- see Shading.
> Shading: Shading = BAD for solar. Mono-and polycrystalline solar panels are greatly affected by just a wee bit of shade, and when solar panels are wired together in an array (say you have 12 solar panels wired in 3 strings of 4 panels in series), when one solar panel is affected, it usually affects all the others in that string, too. The actual amount of power loss depends on how the cells are wired inside the panel and what part(s) of the panel are shaded, but 5% shading can lead to a 95% loss in power produced!!! Absolutely worst is a sharp-edged line of shading across the width of a solar panel, like a shadow from even a single branch or a wire that's close enough to make a sharp-edged shadow. That's like clamping a hemostat or vice across a hose -- it cuts off nearly all the power. Any other panels wired in series with that one (and farther away from the controller or batteries) will also be reduced dramatically. For long strings of panels in high-voltage arrangements (like grid-tied PV) the "pinch point" caused by shading can also get very hot, and can even burn the building down! CiS and other amorphous solar panels get around quite a bit of this, but then, they aren't the ones available at fire sale prices, either. Take-home message: trim the branches or weeds that cause shading or mount the panels where shading is absolutely minimized.


I hope these solar pumping terms are found helpful by someone. My own little solar pump is a ShurFlo 2088 12-volt pump that I run off a 12-volt marine battery charged by an old and ugly 50-watt Arco panel that somehow survived a house fire, and was eventually replaced by a new solar array, plus a Morningstar Sunguard-4 charge controller. The solar panel keeps the battery charged up, and I use the pump occasionally to top off a 300-gallon water tank about 85' away from a pond, and ~18' higher in elevation, which we keep on hand for gravity feed watering of annual raised beds during dry conditions (because the pond eventually goes dry). The pump sits near the edge of a pond in a waterproof plastic container, and only has to suck the water up about 3' before pushing it uphill. A check valve is used to help the pump keep its prime, but this pump is self-priming; the flow check valve just saves a lot of time (and battery power) waiting for the hose to fill and for the water to arrive at the cistern. This pump has a built-in pressure switch with a little room for adjustment, but I usually just run it while working in the gardens, and manually switch it off when I'm ready to leave (I don't have a low-voltage disconnect installed to protect the battery).

Hopefully all this stuff can be used by someone, even though Dave found a good solution for Alex already.

Great info Brad. One thing that did worry me for my own situation is that my lift could be 110 meter meaning a pump of 90 psi ain't gonna cut the mustard.

is there some reason the solar panel has to be exactly where the pump is?

I am wondering, if there is enough flowing water in that creek can you not set up a hydro powered pump to move a small amount of the water uphill? http://www.daycreek.com/dc/html/dc_hydro.htm

Hi Laura, i would love to use a hydro/ram pump but i have nowhere near the flow it would take to power these types of pumps.

alex I am sorry I should have been more specific, check out ram pumps. They require very little water, they simply work more often when there is more water, the power source is the water you are harvesting....this to me is perfection in itself

here is a link with someone using a ram pump from a seep.

http://next-iteration-freyja.blogspot.com/2011/02/hydraulic-ram-pump.html

These require a certain drop from where you get the water to where you are pumping it. I am not absolutely sure this is for you but it is an inexpensive item you should know about. On that page above, there is a diagram of how to build one.

Bob
What would you recommend for a 250' deep well,10gpm. Solar?

A big thanks to Permies and everybody that helped me sort out my water pumping problem,especially Mr Dave Turpin. Finally had everything delivered and have everything up and running. Could'nt have gone any better. I am now able to pump around 4-500 litres per day from a 150 euro 240 watt panel, enough to water all of the kitchen garden and green house throughout the summer. Could not be happier.

pictures are on my blog at: http://permaital.blogspot.it/

Building your own solar panels is not that hard. On Ebay do a search for "solar cells 3x6". You can get 40 1.8 watt cells for around 30-35 bucks. You will need tabbing wire, flux, buss wire, a diode and a soldering iron. Next buy a Solar panel frame for $35-50 and buy a piece of glass locally. You can get glass on ebay as well. You must also seal the cells from oxygen to prevent oxygen from degrading the cells. So look up a Encapsulation Kit as well. There are several You tube videos that explain how to put it all together.
So you can get a 65 watt panel for a about 100-120 bucks








Consider getting a European 220 VAC Inverter to power your normal Well pump. In other words have 2 inverters. One at 110 vac to run household stuff and another at 220vac to run your well pump. Search ebay for "power inverter 220v". They have a Universal Socket on them but if you look carefully the socket will accept a normal power plug. What I would do is wire the power to my well pump through a double pole double throw switch so either grid power is going to the pump or a plug that goes to my Inverter. Look up "Transfer switch"


A word about inverters. They are basically power oscillators and the components take a lot of stress. In other words they don't last very long. If you open one up you will see a long row of power transistors on a heat sink. Testing these transistors isn't that hard. Just unsolder them and test them with an ohm meter. So you might open yours up and get the parts numbers off the power transistors and get some extras. Either that or buy a couple extra Inverters. Or just wait till yours blows up, because it WILL.

How to test a Transistor

[youtube] https://www.youtube.com/watch?v=REW2lF0sb74[/youtube]

Someone give me a little help here ,All our North American Equipment is 60 cycles, the European Union is standardized at 50 cycles Right ! Can we get away with
running a 60 cycle motor off of a 50 cycle 220 vac Inverter? I frankly admit to being over my head here !

Sorry I didn't even notice that. I would think it would not matter but I have not tried nor do I have knowledge that it would work. I did find a couple Inverters that would do both Freq. I also posted a question to one of the sellers since it should be fairly easy to modify one to change freq. Its only 10hz which is very minor. I would love to hear from someone with firsthand knowledge though.

I found a Inverter that will do 220vac and 60hz Here

Villiam Jones : During the aftermath of the Earthquake and Tsunami, It was announced that the Northern Half of Japan was 50 cycles and the bottom half was 60 cycles.
Much then was made of the fact that It was not going to be easy to 'wheel' Electrical power from one location to an other ! Thats what raised a red flag with me !

Something left over from the American Occupation after WW11, I assume ! For the Craft ! Big AL