My Personal Experience

Even before I moved into my current temporary home, one of the early issues encountered was water.  The submersible pump was quite undersized and could hardly pump water to the surface, let alone pressurize the water system.  So I needed to make some changes, including the pump.  I decided to go with a Shurflow 9300 Submersible DC water pump for a number of reasons:

• Greater energy efficiency
• My well is very slow and most DC pumps are also slow, thus giving the well more time to produce extra water during the pumping cycle
• A DC water pump is more likely to function after an Electromagnetic Pulse as it does not depend on an inverter for AC electricity, but rather is powered straight from the batteries which should survive and can be charged from solar panels/hydro/wind which (debatably) should also survive if properly grounded and shielded
• Since the inverter is not required to power the pump, there is less to go wrong with a DC pumping system

Slower Pump

The Shurflo 9300 is not a top-of-the-line pump but does come at a fairly affordable price compared to some others ($700+).  It is capable of pumping 230 vertical feet to an unpressurized cistern and is not recommended for pressurizing a home water system because it is so slow.  But that slowness is what I was looking for when dealing with a very poor well.

This unit is capable of pumping over 80 gallons per hour when connected to a 24 volt battery or 36 gallons per hour when used with a 12 volt system.  If your system is 12 volts and you want the faster pumping speed that 24 volts brings, a transformer may be used to step the voltage up, provided it is capable of handling at least 4+ amps.  When our pump is in operation, it uses plus or minus 100 watts, which is pretty amazing.  The 9300 is also rebuildable, to a certain extent.

My Conclusion

So far I have been happy with it.  What remains to be seen is how well it holds up.  It seems to handle running dry reasonably well, although doing so is not recommended.  When I get the chance, I plan on installing a timer so every drop of water the well produces can be pumped out, but for the present we turn the pump on and off manually to fill our small cistern.

Installation was quite simple, especially since I used the recommended 1/2" drinking quality rubber hose.  Installing a pump can't be much easier than that!  Just make sure you have a good safety line attached to the pump as the hose is more likely to come off than PVC or other pipe.

Although I am happy with this pump, I would probably do something different if I knew then what I know now.  Both Robison Pumps and Sun Pumps look very interesting for my application (200 feet or less of vertical rise) and appear to be of a more durable construction while maintaining a similar price point.  Give all three a good look before you decide on a DC slow submersible pump with 200 feet or less of vertical rise.