solar pump power regulator?

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doctorface

3 posts

Wannabe Geek

#95096 27-Dec-2011 14:53

Hey guys

Im new and know very little about electrical know how but have done a course years ago in basic electronics so have some idea
anyways i have a spa pool that i have hooked up to a small circualting pump that operates on 8w and i have solar panel that produces a maximium of 10w, it pumps water from my spa through 200metres of coiled black pipe on a roof top of a small pump shed that is 1.2metres off the ground, it is wired direct without any circuits but anyways it works very well to heat and pump the water but only at full sunlite in summer, i would like to add on another 10w solar panel so it could possibly work at low level sun(cloudy) but don't want to cook the pump (I may need to add more coils of black pipe, low level sun = less heat but i can work that out), how do i wire something in to restrict the power to 8w, also how do i wire the solar panels series or parrelal, i want this to be very basic as thats what its about, trying to be energy conservative etc

please focus on how to restrict the the solar power feed to 8w's as thats what i need help on expecailly if you disagee or don't belive for what ever reason that what i am doing works as in prior online forums i have had this result although i have had good feed back about geekzone

thanks for reading

hellonearthisman

1819 posts

Uber Geek

Trusted

#561861 27-Dec-2011 15:51

Add a battery, drive off the battery and use the panels to charge the battery. The battery would work like a capacitor.

dontpanic42

1574 posts

Uber Geek

#561869 27-Dec-2011 16:07

Is the pump 12 volt? I assume your solar panel is 12volt? Do you know what type of panel it is... e.g. Monocrystalline, polycrystalline, or amorphous?

If the pump is rated at 8W, then it will only ever draw a maximum of 8W. Even if the solar panel is in full sunlight, and is capable of providing its full rated output of 10watts, the pump will still only draw 8watts from that 10watts.

With your current 10W solar panel, during low sunlight conditions, the panel obviously doesn't have enough juice to power the pump.

If you don't already have the amorphous solar panel type, you could grab one of these
http://www.jaycar.co.nz/productView.asp?ID=ZM9030&form=CAT2&SUBCATID=1004#12
and just wire it up in parallel to the other 10W panel that you already have.
The amorphous panels are better at producing energy in low light conditions. In low sunlight conditions you may just have enough juice from both panels combined to get the pump going at a slow speed, which would probably work in the system's favour anyway as the collectors wouldn't be absorbing much heat anyway.

As suggested above, you could also put a battery into the mix, but you would probably have to add some form of circuitry to stop the pump from pumping all the time so as to not drain the battery.