In most rural areas, wells are still the primary water source. Most of those wells employ electric well pumps to get the water to the surface. These pumps generally run on 230VAC at significant power draw. What happens when the power is off for an extended period of time?
For short term outages, many families use a generator connected to their electric panel to run the well pump. This takes a several thousand watt generator, but works well enough (no pun intended). However, fuel is an issue and is generally limited in supply, so the water is, too.
For long term power failures, there are other options.
If your well is shallow enough, a hand pump may suffice. Various pumps are manufactured for the range of depths found in well water systems, perhaps to 300 feet. The deeper the well, the more manual work you will have to do to get a gallon of water to the surface.
Check the specifications on the hand pump of interest to determine the recommended depth range. Many of these pumps come with sectional tubing and push rods so that you can buy only what you need for your well.
Solar Powered Pumps
There are specialized solar powered well pumping systems. These require the addition of another pumping system to supplement your existing electric pump. With a larger well casing, this is not a problem. These systems typically run on 12 volts, as from common solar panels. A backup battery would allow you to pump water when the sun is not in full glory.
People ask whether they can use a solar panel setup to run their existing well pump. That’s not practical, and here’s why. For a common pump, perhaps 500 watts will be consumed while running. That equates to about 2 amps of current, for a 230V supply. Running such a pump ultimately from a 12V solar panel will require almost 42 amps of current, which is quite large, requiring some pretty healthy wiring. This does not factor in inefficiencies, which make matters worse.
Also, if that were not bad enough, when a motor starts it draws a current perhaps 20 times that of the running current. So your solar panel system would have to produce currents of hundreds of amps every time the well pump starts. Ouch!
The specialized solar well pump systems use smaller motors, and are designed to limit the huge startup currents. They will not pump 10 gallons per minute, but when the power is out and your kids are thirsty, half a gallon a minute is great!
Air Lift Well Pumps
If you run a hose down a well and pump water up toward the surface by some means, you are doing work proportional to the weight of the water being lifted. This makes sense. What if we are not lifting a solid column of water, but water mixed with air? That mix is lighter and easier to lift!
That’s the idea behind an air lift well pump. This type of pump is pretty simple, consisting of two tubes lowered into the well. One tube takes air from a compressor and channels it into the end of the other tube. The air bubbles lift water through the water tube and presumably into a tank at the surface.
The air lift well pump is simple and has no moving parts. It’s easy to make, and lightweight. However, a common complaint is that it only lifts water at one rate. That is, if you change the air flow, the water flow does not change much. The specific flow rate depends on the depth of the water, the distance to the surface, the pipe diameter, and air flow.
Air Operated Well Pumps
If you add a couple moving parts to an air lift pump, you get a water pump that is more controllable. See this diagram of an air operated well pump.
This pump has a couple check valves to allow water to flow in only one direction (shown by the arrow). The diagram explains the various phases of operation. The disadvantage is that the pump has two valves in the air line that have to be operated in sequence, presumably by electrical means, though there are pneumatic valves that could be used for a non-electric solution.
The air operated well pump lifts water out of the well in bursts. The air pressure can be adjusted to vary the force with which water is delivered. The cycling of the valves can be delayed to slow water delivery to any rate needed.
This pump is characteristic of various pumps on the market, some patented.
What Do I Do With All This Water?
Once you have your emergency pump in place, where do you store the water? Some pumps have the ability to connect to your existing pressurized water system, but not many.
A common option is to use a potable water tank to hold some hundred or more gallons of water. You then have a tap for filling containers, or a small hand pump in your house to move the water to where it is used. Pumping water 100+ feet out of a well takes some elbow grease, but pumping it 15 feet from the basement to the kitchen is easy!
Please also be careful because water weighs 8.3 pounds per gallon, so 100 gallons of water makes 830 pounds. This may be too heavy to store on anything but a concrete slab. Be careful of storing water in attics where heat is extreme, and cold could cause the tank to freeze and split, giving you a surprise when the weather warms.