Jeremy, A Grundfos SQFlex model 3 SQF-3 will run on just two 250W 60-cell modules in series. At 600 feet of head, with 500W of PV, it will do just about 1 gpm at noon peak.
However, if the static level is 200 ft in a 600 ft deep well, you have a lot of water storage sitting in the well casing. That will allow you to pump at a rate above the well's underground inflow for some period of time. A 4" well casing holds about 0.6 gallons per foot. The pump will start out only having 200 ft of head, so it will pump at a faster rate, but as the water level drops, the flow-rate will drop off. Hopefully it will reach equilibrium, or the tank will be full, before the pump runs dry. And of course, the amount of sunlight will decline as the day gets later, slowing down the delivery rate, so it may not be an issue at all. The SQF pumps have a low water sensor that will shut the pump off if it does run out of water. If you find the pump shutting off due to low water before the day's sunlight is over, you can also just turn the PV array away from due south to limit output. Another strategy to control pump flow rate is to drill a hole in the pump output piping to allow some of the pumped water to flow back into the well, reducing delivery. Or just install a tee in the pipe above ground, put a valve on it (gate or ball valve), and run a pipe from the valve back into the well. That way you can adjust the valve to get the exact bypass needed for delivery flow control. Brian Teitelbaum AEE Solar -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of All Solar, Inc. Sent: Wednesday, May 07, 2014 2:28 PM To: RE-wrenches Subject: Re: [RE-wrenches] Low flow high head pump Static level is 200 feet Well produces ~1 gallon per minute. 4 inch casing. 200 gallons per day requirement Jeremy Rodriguez, President All Solar, Inc. 1463 M Penrose Colorado 81240 719-372-3808 office 719-372-3804 fax www.asolarelectric.com Sent by Jeremy's iPhone. Sorry for typos and shorthand! > On May 6, 2014, at 6:43 PM, Brian Teitelbaum <bteitelb...@aeesolar.com> wrote: > > Hi Jeremy, > > PV-direct pumps operate at variable speeds depending on the amount of > sunlight and time of day, so a GPM figure is not very helpful in sizing the > pump. It's useful info if the water source will not produce more GPM, since > you don't want to over-pump the source, but it's not enough info to do proper > design. > > What are you pumping out of? Well, pond, spring box? > > How many gallons per day (GPD) do you need delivered, on average? GPD is a > much more useful figure for sizing PV-direct pumps. > > Is that "600 ft" of head measured from the standing water level to the top of > the storage tank, as just elevation change and not distance? > > A 600 foot-deep well might actually have a standing water level at 300-400 > ft. Even if the pump is set at 600 ft, it only takes energy to lift water > from its standing level, so your head figure would be inaccurate if that is > the case. > > If it's a well, what is the diameter of the well casing? > > What are the peak sun-hours at the site during the darkest time of year that > the water is needed? > > There are lots of other questions to ask, but these should help a lot. > > Brian Teitelbaum > AEE Solar > > > -----Original Message----- > From: re-wrenches-boun...@lists.re-wrenches.org > [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of All Solar, > Inc. > Sent: Tuesday, May 06, 2014 5:08 PM > To: re-wrenches@lists.re-wrenches.org > Subject: [RE-wrenches] Low flow high head pump > > Hi all, > Any recommendations for a low flow, high lift pump, PV direct pump. > 1 GPM @ 600 ft of head. Maybe a conventional pump on a timer? > > > Jeremy Rodriguez, > President > > All Solar, Inc. > 1463 M > Penrose Colorado 81240 > 719-372-3808 office > 719-372-3804 fax > www.asolarelectric.com > > Sent by Jeremy's iPhone. Sorry for typos and shorthand! > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
