Solar Well Questions

SystemSystem Posts: 2,511 admin
Hello All,

Pardon my ignorance, but I know nothing about wells, especially elecric vs. solar. I am about to acquire some rural land where I plan on building a house. I will need to drill a well as there is no city water available. I live in Florida, so the threat of hurricanes disrupting power for weeks at a time is a plausable situation.

My ideal situation would be to have a well that relies on solar power so that if the electricity goes out I will still have running water. Is it plausible to do this? If so, what is involved in setting up a well like this? Thank you for the information.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,204 admin
    Re: Solar Well Questions

    I don't have a well--so this is all academic for me... But, a nice looking system is the Grundfos SQFlex series... The pump motors (at least some of them?) have the ability to run on both AC and DC voltages. Really cool, you can run DC solar panels for most of the time and run AC/Generator/battery for backup...

    Try this link for the SQ Flex Product Guides or go to www.grundfos.com and search for literature L-SP-TL-014 (link may not be accessible directly)...

    Also, our Wind-Sun folks here sell Grundfos pumps and equipment--so they would be a very good source to ask for help from.

    Actually, they have the same product guide on their website--so that is probably a better place to start.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Solar Well Questions

    Haha, I grew up with wells and except for a few years in the city, have always lived with wells. The solar part I'll leave to those more experienced in that field, however the basics I can cover.
    First, before you purchase a pump, get your well drilled, to find out from how deep down the pump must bring the water to get it to the surface. AND have that water tested to make sure it's usable, as wells sometimes deliver water loaded with toxic metals etc leached from the underground rock formations and you may have to get another drilled in another location. Hopefully you will have real good water and not too deep down. Most well pump systems provide water to the home at pressures between 30 and 50 PSI, with the pump starting when the pressure drops to 30, it them pumps water into a cold water storage tank, usually inside your home, until the pressure reaches 50 PSI, at which time the pump shuts off. The tank is usually pre-pressurized with air, over a bladder, which prevents that air being dissolved into the water (which over time, perhaps 2 or 3 months, would remove the air). It's the air that provides the pressure to push the water back out of the tank under pressure when you meed it. The air does have to be checked and added to every couple of years, and the instructions for that will be with the tank. There are many types of pumps. Some actually sit inside your home and if the well isn't more than 30 or so feet deep, will "suck" the water up out of the well, but nearly all drilled wells use submersible pumps that sit way down in the water and push it to the surface. The deeper the well, the more powerful the pump you will need. It takes roughly 1 PSI pressure to push water up 2 feet, so if your water is down 300 feet below the surface, the pump must provide 150 PSI just to get it to the surface, and will need to be able to provide another 100 PSI as a safety margin, to make sure it can build up enough pressure to fill the tank and shut off again, especially if the water level drops in the well later on. Otherwise, it could run non stop trying vainly to build the pressure up, using lots of electrical power while wearing itself out.
    A properly installed system will be almost like your freezer, out of sight, out of mind and always there for you. Very low maintenance and very reliable.
    Hope this helps a bit.
    Wayne
  • System2System2 Posts: 6,290 admin
    Re: Solar Well Questions

    Oh, I forgot, there are some people who have "constant pressure" water systems. I HATE those systems. They require that your pump NEVER stops, it's always running, always sucking up electricity providing constant pressure, just in case you might sometime open the kitchen faucet. No wonder North American society is looked on as spoiled and wasteful by most of the world.
    You will soon not notice, or find it inconvenient at all, that your water pressure varies between 30 and 50 PSI. It's NO big deal at all!
    Cheers
    Wayne
  • System2System2 Posts: 6,290 admin
    Re: Solar Well Questions

    I also was wondering about the following scenario. If I use an electric pump and the power goes out, would it be possible to use a solar pump as a backup so I can still have water if I dont have electricity? Thanks
  • mike95490mike95490 Solar Expert Posts: 9,459 ✭✭✭✭✭
    Re: Solar Well Questions
    blantana wrote: »
    I also was wondering about the following scenario. If I use an electric pump and the power goes out, would it be possible to use a solar pump as a backup so I can still have water if I dont have electricity? Thanks

    You have 1 pump, at the bottom of the sealed well shaft.

    You might consider a 100 gallon tank, in an attic, or up a hill, might be easier to run off that for 2 days, than get electric running.

    If it's an AC pump, you might want to wire a DPDT switch to it, so you could run it off an alternate AC power source (generator, inverter........)

    If it's a DC pump, you already have it hooked to solar.

    Water pump starting loads are notoriously high, and you may have to have a very robust inverter with 24V/48V battery, to get it to start properly. (deeper the well, higher the load, you have to get xx Feet of water moving, at once, water does not compress)
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2System2 Posts: 6,290 admin
    Re: Solar Well Questions

    You can also consider a power outage as an emergency, in that, think about it - - just how much water do you REALLY need during an emergency? Thus how much backup supply do you REALLY need. During non emergency times, we tend to let the water run far more than is necessary and use a lot more than necessary, just because we can. All my life, if there's a big storm, or one is forecast, it's common practice to fill a couple of buckets and have them as backup. Some people, if they're really worried, might even fill their bathtub at the beginning of a huge storm. Hey, it is an emergency situation, so we make do with a lot less. To us, it's normal.
    Not telling you what to do, just giving you something to think about. And if there's a nearby stream, just carry a couple of buckets of water if you have to.
    Wayne
  • System2System2 Posts: 6,290 admin
    Re: Solar Well Questions

    That's all well and good. But down here in FL we have hurricanes that knock out your power for weeks. Last hurricane I was in 2 years ago knocked out my power for 2.5 weeks. A couple of buckets of water is not going to last that long. I just think it would be nice to be able to have some water for shower/etc if that happens again
  • System2System2 Posts: 6,290 admin
    Re: Solar Well Questions

    Haha, well you're right about that, 2 1/2 weeks without power would be a whole other story. Here in Nova Scotia, if we loose power for 2 1/2 DAYS, some think the end of the world has come :blush:
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