newb' to run a well pump on part time solar


New Member
hello all, shout out to will for the youtube vid's directing to this forum :)

i'm a complete newb to the solar scene, but been diy for a long while. i've done some basic homestead electrical work, so have some working skill

what i need to do is get my deep well submersible pump system solar compatible by the end of autumn. the idea is in preparation for normal, occasional short term power outages, the freak weather disaster long term outages, and for when/if the SHTF. ideally to run on grid normally, but switch to temporary solar in the aforementioned scenarios. who knows....maybe eventually go solar full time with it when this pump dies

what i have is a grundfos SQ running on 240v. here's some data.

1) it's 2.6 inch diameter body as it's the only size/model to fit in the well since it collapsed 15 years ago from nearby interstate blasting.
2) i have it run off a 1hr cycle timer set to trip every 20 minutes for 30 seconds run time. this is the only configuration i can run since the recovery rate and capacity is so low from the blasting. we lost over 20ft of depth
3) the well is 160ft + deep. i had to pull it a few years ago to repair the electric line, so don't want to do that, again, anytime soon unless the pump dies. iow's, not looking to put in a new/different pump just to run solar by deadline
4) it's a soft start pump requiring no power surge on start up. and, a gentle run time since the well wall is weakened. also, it's designed for immediate stop/start scenarios continuously with no limit, in case you are wondering in terms pump longevity and power load
5) pretty sure it's 1/2hp. not sure how much wattage is necessary, but the same model run on 120v can be run on a 1200w system. i'll find out more on that tomorrow or friday

so far, this is the second forum i've joined, been reading up and watching some vid's, and window shopping at equipment. really not sure where to start, but it seems i can put together a pretty simple kit for maybe under $3k? some things i've determined i'd need are panel/s, control box, inverter, cables, battery/s. and i don't know what else. this is where i could use help. i mean, if the 120v pump needs a 1200w set up, i kinda shudder to think what 240v will need. but, don't know how voltage translates to wattage

thanks in advance,


New Member
i can see this is a FAQ type of question, and i'm doing reading on other threads. i thought i should add

the pump is on a 4 wire feed; 2 hot, 1 neutral, and ground. it runs maximum 36 min's every 24 hrs. at times, less since there are points when the tank is full overnight and the float switch cuts off


New Member
If I'm correct in assuming your well pump can operate at either 120v or 240v AND it consumes 1200w at 120v, it should also consume very close to 1200w at 240v. The only difference would be the Amps needed, ie when running at 120v it would use 10A, but only 5A at 240v. That assumes it's the same motor.


New Member
well, no sooner starting on this than minds have changed. i guess we're going to go with a new gas generator and water catchment to supplement. sorry to waste your time. easier than building a solar system, anyway.