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    For our "well" in the vegetable garden.
    need to lift water about 6m
    I am considering a Maplins sourced 45wp, charging a redundant(i.e. past its best) 12V lorry battery,(or I could purchase a new battery) and a Shurflow type pump.
    to fill a 1750 litre header tank
    The "well" tapping into the run off from the several hundred acres of peat moss behind our house, which runs through below our garden in an 18" dia concrete pipe, about 3.0m deep.
    or i could just run a mains lead from the house 50 m away, but that be far too simple and un-green!
    • CommentAuthorEd Davies
    • CommentTimeMay 17th 2016
    Posted By: orangemannot: “I am considering a Maplins sourced 45wp”

    You can probably get better value for money elsewhere. E.g., http://bimblesolar.com/ though postage to NI might eat the difference, I suppose.

    Posted By: orangemannot: “charging a redundant(i.e. past its best) 12V lorry battery”

    If you have one to hand then by all means use it to get the system set up but don't expect it to last. Applications like this kill even new SLI (starting, lighting, ignition) batteries quickly as they're designed to be recharged immediately. They have large-area thin plates designed to source high cranking currents and are not tolerant to being left in a part-discharged state for long.

    How are you planning to control when the pump runs? Just when the battery voltage is high enough?
    (i) Thanks for that link, Maplins was the "first iteration" in my usually long and tortured/convoluted decision making process. And the 45wp seemed reasonably matched to the 4.5Amp draw of the Shurflow pump, at least with a battery buffer.
    (i) I was aware I would probably need a proper "Liesure" lead acid battery, at least?,which I know, are significently more expensive.

    I would actually rather couple the pump direct to the Solar output, and, after my header tank has filled to capacity then let the surplus water run "to waste", (perhaps artistically driving a waterwheel in the process) across the garden, or via a small pond for the frogs.
    Assuming this would not in some way knacker the pump with insufficient voltage or current.
    On the basis of (effectively) no Sun when the ground is likely to be saturated with excess rainfall, or I can simply turn the pump off or divert the flow back into the storm drain.

    to me this is the perfect match, when the Sun shines we need the water, when it dosnt we dont.
    I like that.

    wot controls
    (probably float switch controlled, cutting out when the header tank is full)
    thanks again
    • CommentAuthorTriassic
    • CommentTimeMay 17th 2016
    Is the bog uphill from you? If so, why not use a surface laid pipe,to a suitably wet area and let gravity do the job for you?
    Not technically feasible, therefore economically feasible ( in the 57 year old water loving farmers son/failed BSc Civil eng. eyes)
    The 18" pipe is 3.0m(measured) below garden level, and was very professionally installed with a minimal gradient, ergo nowt to be gained by "chasing a fall".
    Ed, thanks again for that "bimblesolar" link
    • CommentAuthorringi
    • CommentTimeMay 17th 2016
    The Centre for Alternative Technology has (or had?) a solar powered pump on display that using the PV to charge a capacitance. When charge enough to do one “kick” of the pump, the power is allowed into the pump. This lets the pump run at a rate that matches the power output from the PV.
    • CommentAuthorEd Davies
    • CommentTimeMay 17th 2016 edited
    Posted By: orangemannot: “I would actually rather couple the pump direct to the Solar output”

    Yes, that'd be nice. The problems are:

    0) Even “12 V” panels tend to have a Vmpp around 17 V and Voc well over 20 V. I have some (4) 15 W amorphous panels from Maplin which produce a maximum output current into 12 or 13 V of about 2 point something amps - not the 5 or so amps that a naive thought of 60 W and 12 V might suggest.

    1) In less than full sun you might be able to pump for some fraction of the time on average which you'd lose without some sort of storage. Worse, there might not be enough current available to start the pump but there might be enough to slowly cook it in the absence of the back-EMF when it's turning.

    2) Or the panel is larger than actually needed in full sun for the pump in which case it'll over volt/current in full sun. E.g., 1x15 W panel alone was enough to blow up a computer fan:


    CAT has (had?) a demo with a solar panel driving a pump via a capacitor (actually, a number of fairly chunky electrolytics). There was a small amount of electronics to turn on the pump when there was enough voltage in the capacitors to get it started and to cut it off when it dropped to a level where there was a danger of the pump stalling and cooking.

    The result is that the pump runs intermittently with a duty-cycle proportional to the available sunlight - a sort of very slow pulse-width modulation.

    With current technology something with super-capacitors in series might be practical.

    Dunno if that's the sort of thing you could do yourself. If not that company that Gotanewlife has mentioned a few times might be able to help.

    (PS, cross posted with Ringi.)
    thanks again Ed,
    I just tasked our failed Mechatronical Engineering Graduate student & currently unemployed Son to do some homework on my behalf.
    This should work even if he does not.
    • CommentAuthorgyrogear
    • CommentTimeMay 18th 2016
    Wonder if THIS would do the trick ?


    • CommentTimeMay 18th 2016
    They have a collection of ram pumps at the Lost Gardens of Helligan, they are just great.
    I am reasonably versed in the workings of a Blakes (or other manufacturers) Hydram, having grown up with them pumping water for our dwelling and the livestock.
    I think dad had about 3 or 4 working at one time, as bought and salvaged and re-installed by himself, with my teenage help, on two different streams, they will still no doubt be in-situ in their over constructed protective cramped concrete blockhouses.
    I got NO fall, to speak of, the usual common denominator of a Peat Moss being its flatness, or indeed in a landlocked hollow, in the overall landscape, otherwise the peat could not form.
    I admired the hydrorams at Heligan, through the grimey glass, since at that time, guessing 20 year ago, they were as yet unrestored.
    see link
    Posted By: Ed DaviesWith current technology something with super-capacitors in series might be practical.
    Current technology? Was that a pun?

    Did you mean super-capacitors in parallel might be more practical?

    • CommentAuthorgyrogear
    • CommentTimeMay 18th 2016
    Posted By: orangemannotusual common denominator of a Peat Moss being its flatness, or indeed in a landlocked hollow, in the overall landscape,

    OK, no fall: would you be interested in air-lift by any chance ?
    ( I have a couple of French links FWIW...)

    • CommentAuthorEd Davies
    • CommentTimeMay 18th 2016
    Posted By: davidfreeboroughCurrent technology? Was that a pun?
    Not deliberately though I did wonder about putting some sort of note/excuse.

    Did you mean super-capacitors in parallel might be more practical?
    Been a while since I looked but IIRC super-capacitors tend to have low maximum voltages (2.5 volts or so). Putting them in series allows higher voltages for the same capacitance. You need a resistor chain down the side to keep them balanced.
    getting warmer(or should that be wetter?)
    Anyway, presuming tis Ok to post a link(to a commerical site)
    I found this site genuinely very useful;
    • CommentAuthorEd Davies
    • CommentTimeJun 4th 2016
    Posted By: davidfreeborough: “Did you mean super-capacitors in parallel might be more practical?”


    Julian Ilett. 100 F 2.7 volt capacitor. Mildly interesting if you're interested in that sort of thing. Little aside about supercaps available on boards with protection and balance circuits. Do wish he'd get a proper bench supply and measure things, though.
    Re-visiting thissun, since I am now retired, and started gardening.

    Has anything changed, technology wise?

    • CommentAuthorMikC
    • CommentTimeMay 5th 2018
    PV has got cheaper :)
    Ay, but I got neither any wiser nor better educated, in the meantime.

    but see link;


    is this a suitable panel/kit?

    Oops !
    I finally remembered the name of the solar outfit , someone on here recommended suggested = Bimblesolar
    • CommentTimeMay 5th 2018
    Posted By: MikCPV has got cheaper :)
    Not by much
    • CommentTimeMay 5th 2018
    Seems to me that either the bimble solar water pumping page or the AltE products (surface shurflo pump & shurflo linear booster perhaps) would be good places to figure out what was required to make a working system. Then check whether they are overcharging enough to make it worth looking elsewhere to actually buy the kit. If they're not overcharging, then the project is nice and simple :bigsmile:
    Maybe work out a way to do it in 2 or 3 stages with those little submersible 12V pumps.

    Use small float switches and relays to protect the pumps and switch the panel to power one at a time, bit tricky though :-S
    I found this pump


    with a 20 W solar kit, incl solar charge controller, from "Photonics" off ebay for £50.00

    plus an £18.00 battery Guard for pump motor undervoltage protection

    Plus a 12 V battery

    Should pump a min of 1000l per day?

    Ay surplus can overflow back into the "well"

    Which will suffice

    How many litres a day need to be pumped?
    None, absolutly, but guessing I should get at least 1000 l per day (as per my above comment)

    I might buy a 50W or a 100W solar panel kit, to be sure, to be sure

    100W kit c/w solar battery charge control unit is only £100.00 odd off Ebay/Amazon
    cheers all
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