Different Types of Pumps
Pumps do not like to pull (or suction). They are much more effective at pushing. For this reason, we have two main categories of pumps--submersible and surface (along with the numerous subcategories for each). Because the water level in wells is often greater than 15-20 vertical feet (the usual maximum distance any pump can pull or suction), the submersible pumps are used in this application--so they are submersed in the water and can push rather than pull. For applications where water is already at or near the surface, a surface pump is used to push the water somewhere else and/or pressurize a water system. Lets take a look at some of the options.
Pitcher or Cistern Pumps
These hand pumps come into their own when you have an energy independent means of pumping water to your cistern and want a completely power-free way to pump that water to your house. Pitcher pumps (AKA cistern pumps) bolt to your counter top and can pull water from a cistern or even shallow well as long as the water level will never be more than 20 feet in elevation below where the pitcher pump will be mounted. Certain higher-end models feature a pipe connection for forcing water up to a tank in the second story of your house. Even if using a hand pump is too primitive for you, pitcher pumps are a wonderful backup for pulling water from your cistern.
Gasoline Powered Water Pumps
Although these pumps use a resource which would not be available in a time when buying and selling is impossible, they may still have a place for specific situations. Gasoline powered water pumps must be placed within approximately 15 feet in elevation of the water source (stream, springhead cistern, etc.) but some models can pump water to over 100 feet in elevation above the pump. They are very good at moving large quantities of water periodically (i.e. filling your cistern once a week) and are usually quite conservative on using gasoline (in our experience, around 1 quart of gasoline will pump 1,200 gal. of water 100 feet in elevation uphill through around 600 feet of 1 ¼ in pipe in 45 minutes). Here are a few tips on the use of these pumps:
Always make sure it is properly primed before using (running the pump dry could damage your pump).
Remember to drain the water out of the pump after every use in the winter or anytime it could freeze (this includes draining the suction pipe).
At the very bottom of the water line (right next to the pump), install a 1 inch valve and pipe for quickly and easily draining the system down to the pump. Place the pump at a location where spring floods will not wash it out.
Before buying, be sure to know the head (elevation rise) that the pump will need to be able to handle. Another use for gasoline powered water pumps is for fire protection in dry climates. A cistern of water on the back of a pickup truck and a good water pump could be a very good idea if wildland fires are a possibility in your area. Our Honda water pump has performed very well and has given us good service (it even survived freezing with water in it with minimal damage). Other water pump manufacturers are listed here.
These pumps are primarily used to pressurize a household water system from a nearby cistern but can also be used in wells with a static water level of around 20 feet or less. Unlike submersible pumps, piston pumps are usually located in an outbuilding. They suction water up from 20 feet or less below and can pump quite a distance uphill, but are often used to pressure a household diaphragm tank in the house. Piston pumps can be obtained in 12, 24, or 48 volts DC with some models also being available in 120 volts AC. They are probably the most energy efficient way to move water from the cistern to your home with pressure. 120 volts AC submersible pumps are another option for doing that but are probably not as energy efficient.
If the cistern is located within a couple hundred feet of your house, using one of the DC models would be preferable as there is less power serge requirement when the pump starts up, the power would come directly from the battery bank which eliminates losing power through the inefficiency of an inverter, and because it will free up your inverter to handle other items that might need electricity.
But if the pump will be some distance away, a 120 volts AC model might be best because 120 volts AC is able to run on a much smaller (and thereby economical) electrical wire. Another option with one of these pumps is to connect it directly to an array of solar panels for operation during sunny days. Certain models can be obtained which can be operated this way. We recommend the Dankoff Solar Force piston pumps as they have an excellent reputation for longevity.
Like piston pumps, a booster pump will take water from a nearby source that is above or below the home and pressurize it in one's household (utilizing a household diaphragm tank). If the water source is above your home, but not far enough above it to yield acceptable water pressure, a booster pump could be the ideal solution to pressurize your household diaphragm tank. It could relieve you from needing to install a pump and extra cistern above your home for a gravity flow system. This is a surface pump that must be within . 12, 24, and 48 volts DC and 120 volts AC models are available with the DC models being preferable for operation within a couple hundred feet of your home due to more efficient energy use. The Flowlight booster pump, manufactured by Dankoff is an excellent choice.
Another option is the Dankoff Slowpump. It is DC powered and is a great little pump for slowly and efficiently moving water up to a cistern. It is capable of lifting water 450 feet if it is not pressurizing it, and is can operate straight off of solar (linear current booster recommended). This is not typically suited for pressurizing a system, as the flow is not very great, but it is an efficient water mover.
12, 24, and 48 Volt DC Submersible Pumps
While 120 volt AC pumps are great for pumping water out of a well and straight into a diaphragm tank (pressurized), these DC pumps are used primarily for moving water from your well, springhead cistern, etc. to another cistern above your house. In other words, a non-pressurized use, where all you want to do is move water with the least amount of electricity. For applications like these, DC water pumps excel, because they require less electricity to operate than the 120 volt AC pumps and can be run straight from batteries or (for certain models) directly from solar panels.
DC submersible pumps are not generally used for supplying pressurized water straight to a house because they pump slower than their AC counterparts. Once again, they are great water movers. Grundfos is one of the leading submersible AC/DC pump manufacturers and their SQFlex series of pumps is capable of lifting water up to 800 feet to a cistern (less if it will be used to pressurize the water). This pump is capable of operating on a wide variety of voltages from both AC & DC electricity. Sun Pumps also manufactures efficient DC powered solar pumps capable of pumping water up to 600 feet to a cistern (less if it will be used to pressurize the water).
120 Volt AC Submersible Water Pumps
Normal submersible well pumps are 120 or often 240 volts pumps that can use very large amounts of electricity and have a big power serge requirement when the motor starts up. This serge is important because it is often so large that many inverters (in an alternative energy system) cannot handle it. Here is where the "soft start" feature fits in. It is more efficient than regular pumps and features a "soft start" which avoids the large serge of power when the pump turns on. These pumps can be run on an alternative energy systems which makes it an excellent option for those with a well who want to be free from dependence on utility companies.
One of the best options in this class is the SQ series, made by Grundfos . Regular 120 volts AC submersible pumps may be used as long as you are certain your inverter can handle the serge requirement of the pump motor. 240 volts pumps should generally be avoided when using an alternative energy system with a battery bank because the inverter that converts the DC electricity in the batteries to AC electricity normally does not supply 240 volts, but 240 volt inverters are becoming readily available.