Homestead mailing list

[Roy Morgan <k1lky AT earthlink.net>]

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