Tuesday, July 11, 2017

LND: Water.

   Water is just below air at the top of the list of things you need in order to postpone dying.  Virtually unlimited, uninfected supplies of fresh water are one of the unsung heroes that enabled the big lifespan increase in the Western World through the 20th Century.  So maintaining the flow is a high priority.

The Typical Farm Well Pump...

   The best source of clean water is a well drilled into a reliable aquifer.  The most common set-up for getting the water from the bottom of the well to your spigots is a grid-powered, automatic, submerged pump with pressure tank.  If you acquire rural property with an established home site, this is what will probably already be there.  If you buy raw land, this may be the simplest thing to have installed.

   The well casing is essentially a big (usually around 6" diameter) pipe that goes straight down to into the ground to below the water level.  Near the bottom of the casing, deep under water, is the actual pump.  A cylindrical thing connected to what is essentially a heavy-duty hose and some wires which run back up the casing to the surface.  The upper end of the hose connects to pipe which, in-turn, connects to a 20 to 50 gallon tank and then out to the homestead plumbing. The wires from the pump run to a pressure switch at the tank, which then connects to the household panel electricity.

   When the pressure in the tank is below a set minimum (usually 30 to 40psi), the switch will send electricity to the pump, which will force water up the hose pipe into the bottom of the tank, compressing the air in the tank into a smaller space at the top.  When the pressure reaches a set maximum (usually 50 to 60psi), the switch will stop power to the pump.  The compressed air in the top of the tank acts as a spring, maintaining fairly constant water pressure for the plumbing without the pump needing to switch on every time water is used.

   Wells under 100' may use surface pumps to pull water up, but deeper wells, and the higher flow rate needed for farms, makes the submersible pump more common in most rural areas.

Alternative Power For Standard Well Pump...

   If you've set-up a backup generator for your doomstead (as detailed in another chapter), you're already ahead of the game.  The well pump should be powered along with everything else when your generator is going.  But you may not want to run the generator 24/7.  So be sure to flush your toilets, fill your water jugs, top-up the livestock troughs, and so-forth while the generator is going. 

   A freestanding solar power station is a more long-term (not to mention quieter) solution for running the well pump.  (You may want to read through the Generator chapter for some info on basic electrical stuff.)

   Contrary to what you may have seen on Captain Planet, photo-voltaic solar panels are kinda' wimpy.  The standard circuit feeding my well pump can provide 3,600 watts.  It would take thirty big solar panels to collect that much power.  At high noon. On a clear day.  So you can't just run a typical well pump system directly from solar panels.

   Fortunately, a pump doesn't draw full power constantly.  In fact, most of the time, it doesn't use any.  When it cycles on, it pulls a big surge of electricity for a second or two, then settles down to more moderate wattage until the pressure maxes out and it cycles off again.  While solar panels collect only a relative trickle of energy, they do it for hours on-end on clear days.  That can add-up to enough to supply the big gulps of power needed for the pump, if you have some way to store the accumulated energy.

   We have two 12 volt, 10 amp solar panels connected to four big marine 12v  batteries.  (These are better for extended charging/output cycles than automotive starting batteries, and better for the high-amp starting load from a well pump than pure deep cycle batteries.)  There's a 35 amp-rated charge controller between the panels and batteries, which keeps the batteries from being overcharged by effectively disconnecting the panels when the battery voltage gets above 15v, reconnecting them when it drops below 13v.  During the day, the solar panels act as a trickle charger to top-up the batteries for when the pump needs power, day or night.

   Problem is, the solar panels and batteries produce low voltage, Direct Current.  The well pump runs on 240v Alternating Current.  To rectify this, we use an inverter.  A device which inputs low voltage, high amp, DC electricity and outputs high voltage, low amp, AC electricity.  Once connected to the inverter, the pressure switch controlled well pump works exactly the same as when it's on grid power.

   Naturally, the solar panels have to be out in the open.  Usually oriented to face directly towards the sun at midday in the Spring and Autumn.  It may be worthwhile to mount them in a way that allows you to adjust them (more upright in Winter, at a shallower angle in Summer) to catch maximum sunlight.

   The batteries and charge controller need to be under cover.  The inverter is the most vulnerable component, and needs more protection from the elements.  It is also capable of producing sparks which could ignite gas vented from the batteries.  So the inverter needs to be enclosed separately from them.  We have the batteries under an old camper shell, with the inverter in a large wooden box also under the shell.  A canister of silica gel beads are kept in the box like a gun safe, to reduce moisture condensation on/in the inverter.

   Remember that low-voltage, DC electricity doesn't carry well over distance.  Keep your components reasonably close together, and wires short.  Use the heaviest wire practical for connecting the panels to the charge controller, and controller to the batteries.  Use the thickest automotive battery cables and clamps to connect the batteries to one-another and the inverter.  Our inverter takes 12vDC input, so the entire DC side of the system is wired in parallel.

   We use a modified sine wave 12vDC to 240vAC inverter which is considerably more affordable than pure sine wave inverters in the 5000 watt range, and works just as well for our purpose.  Oddly enough, it has weird sockets designed to accept a lot of different electrical plugs, including standard American 120vAC extension cords.  This could actually be a hazard if someone plugged a 120vAC device into these 240vAC-only sockets.  But, since the inverter is out by the well house, that's not likely to happen, and the use of a common plug came in handy for us.

   After switching off the pump circuit at the main panel (of course), I reworked the well house junction box so that, instead of connecting the underground electrical conduit from the house to the pressure switch, the line from the house connects to a short 'pony tail' ending in a heavy-duty standard type extension cord socket.  The line from the pressure switch connects to a section of heavy extension cord long enough to reach the inverter in its box, and ends in a standard plug.  This enables me to switch pump power from grid to solar simply by unplugging from one and plugging into the other.  There is no 'suicide cable' risk, as the pronged plug is never live when out of a socket, and no chance of backfeeding as the well can only be plugged into one power source at any given time.

Operating Notes:

   Always power-up the inverter first, then connect a load.  In fact, I've found that it's best to leave the inverter on at all times, even when your using grid power, as powering up from cold seems to really tax the electronics.

   Try to do your heavy water use in the middle of the day, so that the batteries will be charged up by the morning sun after the night's drain, and so that the afternoon sunlight can charge the batteries up before the coming night.

   You may need to open up your power system to fresh air in the heat of Summer.  The inverter will shut down if overheated.  Remember to put the lid on your silica canister when the inverter box is open.
   Still on my To Do List (yes, after two decades on the doomstead, I still have a long one!) is the addition of a small wind turbine to top-up the batteries during the dark seasons.  It should be possible to simply wire it in like another solar panel, although another charge controller may be needed.

   During the aforementioned extended periods of gloomy weather, I have run a trickle charger to keep the batteries up on occasion.  In a few pinches, I've used jumped cables from an automobile to charge the battery array. 

Off-Grid From the Start...

   If you're starting from scratch, or determined to be fully self-sufficient, you may want to skip the whole grid AC and pressure tank set-up altogether.

   You can't get much more Old School than a hand pumped well.  (Well, you could lower a bucket on a rope, I suppose.)  No electricity involved.  Back down in the Lowcountry, a lot of Old Timers (including my grandfather) insisted on having a pitcher pump backup for their well.

   Of course, hand-pumping water for just household use can be a big chore.  If you need more fore livestock, irrigation, etc., a hand pump isn't going to be sufficient.

   But it's not quite rocket science to build a windmill and have it mechanically drive the pump for you.  You'll see this sort of thing filling stock tanks on big cattle farms across the country. 

   If you set up a windmill-driven pump, and have it push water into a water tower, you can not only have plenty of water even when the wind is calm, but also have gravity-provided water pressure to your plumbing.  (You'll need to make sure the bottom of your water tower is a few feet higher above the ground than your highest shower head!)


   A limitation on hand and mechanically-driven wind pumps is that they can't pull up water from very deep wells.  Nothing really beats a submersible, electric pump for that.  But, using the same water tower approach as a windmill, you can forego the battery array and inverter to have solar panels and/or wind turbines power the well pump directly.

   The problem is that low voltage, DC pumps drive water up the pipe slowly and at low pressure.  So they won't work with a typical pressure tank.  But they can tickle-fill a water tower whenever the sun shines or wind blows...  If you have enough panels and/or turbines. 

Artesian wells...

   Some underground water sources are naturally pressurized to the point that you don't need a pump at all.  Just drill a pipe into the aquifer and the water gushes up.  But you're very lucky if that happens, because it requires rather specific geological conditions which are not that widespread.

Other sources...

   Deep wells are your safest, most reliable source of potable water.  Surface water, such as creeks, ponds, springs, collected rain, and condensation are subject to many sources of pollution.  As infrastructure declines, the likelihood of surface water sources being contaminated will get even worse.  

   Filtration, boiling, distillation, UV, and chemical purification of surface water may be useful means to get through rough spots.  But, unless you are part of a group that can do this on a fairly large scale, it won't be enough to maintain a comfortable standard of living long-term.


   In the Doomstead Layout chapter, I mentioned that you want the well house near the middle of your barnyard to minimize hose drag.  Even so, you're probably looking at 100' or more hose to reach all the stalls and paddocks.  Don't cheap-out and try to use ordinary, vinyl-shell garden hose.  Not only will it fail often (I mean every few weeks), but it also doesn't patch well due to its layered construction.  Get the heavy, solid rubber hose.  It's more than worth it.

   For the 'way down yonder' troughs and garden sprinklers, it may be a good idea to just leave a section of hose running back from them to within range of your regular hose, so you can just connect to run water out there without having to drag the full length every time.

   Rather than a spray head or other restrictive valve on the hose (which slows down bucket filling), I prefer about a 6' section salvaged from an old hose with replacement fittings on both ends.  Having this on the end of the main hose allows me to crimp the water off a few feet from the outlet as I thread the hose through a stall wall or paddock fence to water the stock, or to allow easy connection to one of the aforementioned extension lines.  The frequent crimping will wear the hose, but just the easily replaceable 6' piece. 

   Weird thing about the solid rubber hose is that it will conduct high voltage electricity.  So you (or your critters) can get zapped running it over an electric fence.  Wrapping about 18" with electric tape just where you need to lay it across the fence will fix this.


   Solar panels can last decades.  Batteries can go several years, and can be rejuvenated if replacements aren't available.  Charge controllers seem fairly tough, and you can get by without them in a pinch if you figure out how to balance panels/turbines, batteries, and power usage.  Inverters are the weak link in standard well pump to alt energy conversion.

   Modern, electronic inverters are simple to use, provide very stable output, and are very efficient.  But moisture, heat, overloads, and various other things can mess them up.  And they aren't easily reparable.  So it's worth investing in a backup or three for the long term. 

   It's also probably a good idea to look into old-fashioned mechanical inverters, dynamotors, and the like.  These are basically some form of DC motor driving an AC generator or alternating switching system into a transformer coil.  Nowhere near as efficient or self-monitoring as modern electronic inverters, but they can give you AC from DC sources, and can be repaired or even built from scratch by a handyman.




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