Subject: Re: [Homestead] Solar System for well pump
Date: Mon, 3 Nov 2008 22:27:13 -0500
On Nov 3, 2008, at 7:58 PM, Robert Walton wrote:
Someone here posted a while back that they have bought or are going to
buy a solar system for their well pump.
Rob,
It was not me. I may have mentioned the idea of having a solar run
pump to get water out of a dug well here, and into a pond very
nearby. No pressure, no big lifting distance, and people would not
depend on it.
And I don't have any facts on solar electric systems, but here is my
guess about the idea:
A well pump of the normal sort might be like this: drilled well, maybe
100 feet deep, and feeding a 40 PSI accumulator tank in your cellar.
It takes more than a couple of light bulbs worth of power to run the
pump. It runs only some of the time, of course, depending on your
water use. The circuit might be 220 volts, and draw maybe 20 amps on
startup and 7 to 10 running. This would require a very bug solar
system to run the thing.
One difficulty with solar power is that the solar cells on the roof or
wherever make direct current. In order to have electricity of the
sort used by many household systems, (and most well pumps) you have to
both store the power and then make it into alternating current. This
means batteries and somewhat sophisticated electronic conversion
devices.
All that may add up to a solar system which you can't afford.
Begin the Conjecture Part:
Now, instead of having a 40 PSI water system, you have storage tank in
the attic, and you count on the solar system to run a DC pump of
small size to simply put the water into the tank, it could be a whole
different story. The pump would run as long as needed to fill the
tank in the daytime at whatever rate it could. You would have very
low water pressure in your house, and no water heater maybe. The pump
could deliver low volume all day and none at night.
I await ideas from folks who may have some facts and may have thought
it out more.
Roy
Roy Morgan
k1lky AT earthlink.net
529 Cobb St.
Groton NY, 13073