PV Gap

Anthony Said:

I need a switch to turn off a water pump at night?

We Answered:

Your second example is way over complicated to do a simple job. Just use a light sensing relay.

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Katherine Said:

How to pump water from a stream?

We Answered:

A surface pump would do it for you. You'd need to protect it from the weather, but it goes beside the stream instead of in it. SHURflo makes a 12V pump that can be powered directly from a solar panel. It is self priming up to 12'. http://www.altestore.com/store/Solar-Wat… A 135W panel would power it at about 2 1/2GPM. http://www.altestore.com/store/Solar-Pan… You can optionally have a controller with a float switch that would turn it off when the tank is full.

Kathleen Said:

what specific power or capacity of water pump we need for an irrigation?

We Answered:

Figure how much water (in gallons per hours) you can move with your pump, and figure out how much water is consumed by your crop (rainfall totals, Farmer's Almanac, whatever).

This will tell you what size of field your pump will irrigate and will let you know how close your source water has to be.