Flood relief off grid solar

Howdy y'all.

I have an interesting problem and some experience with off grid solar and I'm looking for advice before I make a decision.

Here's the deal:
I live in Lyons, Colorado, which just got hammered by floods. My place is generally fine, but we've all been evacuated and there is no power, no gas, no water, no sewer. They are saying it will be 2 to 6 months before folks are allowed to move back in. It's unclear when they'll have gas and power back on -- they are saying they don't want gas and power back until they can provide fire protection (seems like a few weeks out, but unclear at this time). It's also possible that the power connections to this particular spot are trashed (the river ate an electrical box adjacent to the property).

I'm trying to help some friends with their basement, which was badly flooded and now sits pretty close to where the new river runs. It has sump pumps which quit when the power went out. I want to power them up again to help the basement stay dry and avoid mold growth (it's been wet for a week now). I think we can power one at a time and they draw 400 watts. I'm concerned the thing is going to run continuously, 24/7. The sump isn't very big and my recollection is it runs all the time (possibly a crummy design, or maybe the float switch should be higher or something). So that's 9600 watt-hours/day (pretty damned big load, really). There's actually a large natural gas backup generator on site... which doesn't work because they actually turned the gas off before the electricity... They are letting us in to do work intermittently.

Question 1: What could I do, or should I do, to cut the load down? Buy a smaller pump? Use just the "back-up" pump, which I believe has a higher float switch position? Just put it on a cheap timer and use that to chop the load (i.e. on for 30 minutes, off for 30 minutes?)

Question 2: Could I rent a solar powered system for a few weeks or a month until we get power or gas? Any recommendations?

Question 3 is: What would it really take to cobble together a system? They might have a solar-powered golf cart sitting there. I scoped it out earlier, before the evacuation and I believe it has 6 T-105 batteries and a 120 watt solar panel. It's set up as a 36V system, but I'm assuming I could ditch the panel and just use the batteries configured as a 12V system.

I'm wondering if I could cobble together a hybrid generator and solar system with a significant battery bank. Assuming we could get in there every day, we could run a generator for an hour or two in the morning and then maybe again later in the day. In theory we could also add solar to this system. If the batteries are good for 4000 watt-hours of storage and I could cut my load down by putting the pump on a timer of some sort, I think we could make this work. If I cut it down to 6 hours of runtime between generator runs, then the battery bank should be able to handle it pretty well. I think we could get a pretty cheap generator new and then keep it for the next time they lose both gas and electricity.

Question 4: What's out there for a good, inexpensive 12 V inverter/charger that would mate well with a 12 V, 675 Ah nominal battery bank?

Of course folks are concerned about money, given that they are all out of their houses, etc., so cheaper is definitely better. I'll be doing my homework, but nothing obvious has jumped out yet. Thanks a bunch for any ideas you might have.

Comments

  • bill von novakbill von novak Solar Expert Posts: 891 ✭✭✭✭
    Re: Flood relief off grid solar
    Question 1: What could I do, or should I do, to cut the load down? Buy a smaller pump? Use just the "back-up" pump, which I believe has a higher float switch position? Just put it on a cheap timer and use that to chop the load (i.e. on for 30 minutes, off for 30 minutes?)

    There are a variety of lower power pumps, but you're not going to get around the power needed to lift X pounds of water Y feet in Z seconds. A larger pump will run less often; a smaller pump will run more often.
    Question 2: Could I rent a solar powered system for a few weeks or a month until we get power or gas? Any recommendations?

    Unlikely. They're not commonly "rented" items. Might be able to borrow some panels from a helpful supplier or homeowner.
    Question 3 is: What would it really take to cobble together a system?

    Take the batteries, borrow a few 12V panels, get a 12V PWM controller (cheap) and get a 12V sump pump. Ideally you'd use a second controller set up as a LVD to protect the batteries against overdischarge. Make sure you protect it with adequate fusing on the battery + terminal - that's the big risk for fire in the event of a short.

    In the short term borrow a small generator to run the main pump to clear out most of the water, and use the 12V system to keep it dry.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Flood relief off grid solar

    i'm not so sure solar is the answer here. get a good inverter generator and use it to power the pump. they are good on gas, but you may need to run more than one pump to get any real volume of water out of there in a quicker manner.

    you would also need to stop in and refill the gasoline for the genny periodically.
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Flood relief off grid solar

    In my experience solar isnt something you really 'cobble', being neither cheap not quick. A generator is what springs to my mind.

    However a RV style 12/24v pump could maybe be rigged off the golf cart. Theyll pump 10l/min, draw about 75watts, and will run for a couple hours without melting. I have no idea how much water we are talking but assuming you ran it for 2 hours a day, thats 1200 litres, and 150Wh.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Flood relief off grid solar

    Go right to gasoline-driven pump would be my suggestion if you've got the huge volumes of flood water to remove.

    Solar to produce that kind of Watt hours would be big and expensive.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Flood relief off grid solar
    Go right to gasoline-driven pump would be my suggestion if you've got the huge volumes of flood water to remove.

    Solar to produce that kind of Watt hours would be big and expensive.

    good point coot as i totally forgot about those.
  • MainerInExileMainerInExile Registered Users Posts: 6
    Re: Flood relief off grid solar

    I think the plan is to use a gas powered pump tomorrow to pump the place out. I'm trying to work out a long term solution to keep the place dry over say the next month or two and that's what I really need help designing, as we're not going to run a generator for the next 1500 hours.

    In the immediate term we're talking gas powered pump and/or generator.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Flood relief off grid solar

    If you need to have back-up or off-grid power to run a pump you can skip the solar part and go with batteries + inverter to power the pump, and then recharge the batteries from the gen (or utility) with a charger. Not perfect, but cheaper than investing in solar panels & controller and will work in any kind of weather.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Flood relief off grid solar

    good luck with this and let us know in general how it went.
  • TulumtamTulumtam Solar Expert Posts: 37 ✭✭
    Re: Flood relief off grid solar

    It may be too late to chime in on this one, but I'm not on here every day!

    What about a PV direct pump? You can get a good 4-5 hours a day of pumping without worrying about damaging batteries or running out of fuel.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Flood relief off grid solar
    Go right to gasoline-driven pump would be my suggestion if you've got the huge volumes of flood water to remove.

    Solar to produce that kind of Watt hours would be big and expensive.

    I agree. Instead of burning gasoline to generate electricity to run an electric motor to run a pump it makes more sense to me to run the pump directly off the gasoline motor.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Flood relief off grid solar
    Tulumtam wrote: »
    It may be too late to chime in on this one, but I'm not on here every day!

    What about a PV direct pump? You can get a good 4-5 hours a day of pumping without worrying about damaging batteries or running out of fuel.
    I don't think that would be practical if there is a very large volume of water to move.
  • BeachnutBeachnut Registered Users Posts: 3
    Re: Flood relief off grid solar
    Howdy y'all.

    I have an interesting problem and some experience with off grid solar and I'm looking for advice before I make a decision.

    Here's the deal:
    I live in Lyons, Colorado, which just got hammered by floods. My place is generally fine, but we've all been evacuated and there is no power, no gas, no water, no sewer. They are saying it will be 2 to 6 months before folks are allowed to move back in. It's unclear when they'll have gas and power back on -- they are saying they don't want gas and power back until they can provide fire protection (seems like a few weeks out, but unclear at this time). It's also possible that the power connections to this particular spot are trashed (the river ate an electrical box adjacent to the property).

    I'm trying to help some friends with their basement, which was badly flooded and now sits pretty close to where the new river runs. It has sump pumps which quit when the power went out. I want to power them up again to help the basement stay dry and avoid mold growth (it's been wet for a week now). I think we can power one at a time and they draw 400 watts. I'm concerned the thing is going to run continuously, 24/7. The sump isn't very big and my recollection is it runs all the time (possibly a crummy design, or maybe the float switch should be higher or something). So that's 9600 watt-hours/day (pretty damned big load, really). There's actually a large natural gas backup generator on site... which doesn't work because they actually turned the gas off before the electricity... They are letting us in to do work intermittently.

    Question 1: What could I do, or should I do, to cut the load down? Buy a smaller pump? Use just the "back-up" pump, which I believe has a higher float switch position? Just put it on a cheap timer and use that to chop the load (i.e. on for 30 minutes, off for 30 minutes?)

    Question 2: Could I rent a solar powered system for a few weeks or a month until we get power or gas? Any recommendations?

    Question 3 is: What would it really take to cobble together a system? They might have a solar-powered golf cart sitting there. I scoped it out earlier, before the evacuation and I believe it has 6 T-105 batteries and a 120 watt solar panel. It's set up as a 36V system, but I'm assuming I could ditch the panel and just use the batteries configured as a 12V system.

    I'm wondering if I could cobble together a hybrid generator and solar system with a significant battery bank. Assuming we could get in there every day, we could run a generator for an hour or two in the morning and then maybe again later in the day. In theory we could also add solar to this system. If the batteries are good for 4000 watt-hours of storage and I could cut my load down by putting the pump on a timer of some sort, I think we could make this work. If I cut it down to 6 hours of runtime between generator runs, then the battery bank should be able to handle it pretty well. I think we could get a pretty cheap generator new and then keep it for the next time they lose both gas and electricity.

    Question 4: What's out there for a good, inexpensive 12 V inverter/charger that would mate well with a 12 V, 675 Ah nominal battery bank?

    Of course folks are concerned about money, given that they are all out of their houses, etc., so cheaper is definitely better. I'll be doing my homework, but nothing obvious has jumped out yet. Thanks a bunch for any ideas you might have.

    MainerInExile

    My condolences for having to live through such a hard situation. Many people think when the water / floods recede, the problem is over. But I know, the work lasts for years to put things back together. I went through two back to back multi week floods from the Napa River, in Napa, CA. It was horrendous! The "mud" that is left behind in houses, in walls, even behind sheet rock, is a combination of raw sewage, toxic waist, and natural mud. Be ever careful when dealing with it, as you surly can get real ill from it. (When the "mud" dries, it turns into toxic dust which is easy to breath in too!) Our subdivision that I lived in was "protected with a levy", and a natural gas emergency back up generator, to keep the neighborhood park pond pump running to keep us from flooding internal. The levy circled the entire subdivision, the pump was to pump the storm drain water from the central park pond / sump for our storm water, out to the flooding river. Was told upon buying the house "a 100 year flood will not touch you", yea, right!! Yup,, as soon as the flood from the Napa river hit the town, power went off, and sure enough, they shut the natural gas off too! No nat gas,, no generator for the pump for our neighborhood, and we flooded from our own storm water, and a levy breach on the inland side levy from another 6' diameter storm drain breach / backed up from the river being too high for water to flow into it... Living through such events can mess with ya for years, financially and mentally. (Just wait till it rains hard again, and you will see)...

    I can not help with your questions, other than to say gasoline generators worked best in our case. They actually brought in some HUGE gasoline pumps used to drain dry docks at Mare Island Naval shipyard to drain our neighborhood. The rest of town was drying out, but our neighborhood was like a swimming pool! Those huge pumps were totally amazing and ran for days! I hope all your family remained safe. I also hope they do not rebuild in the "flood zones" again, as many did in Napa. But they finally built the "Major flood control project". Time will tell if that works..... I just moved to the "dry" side of town, then left that tourist trap entirely! My thoughts and prayers are with you and your community.
  • MainerInExileMainerInExile Registered Users Posts: 6
    Re: Flood relief off grid solar

    Thanks folks for the advice, etc.

    We wound up with a low cost, non-solar option. We rewired the golf cart to just serve as a big 12V battery bank, then purchased an inexpensive charger, inexpensive inverter, and borrowed a generator. The larger pump actually draws 900 watts, which is a lot of juice. We basically go in, run the generator for a while (like 4 hours) to run the pump and the charger, then plug the pump into a timer plugged into the inverter to run intermittently over the rest of the day. It's working OK. We are hoping to get electricity turned back on in the next week or two, so the low cost option made sense. We have about $300 into modding this system between wire, inverter, and charger.

    This experience has gotten me thinking though about configuring solar systems with an option to change array connections to serve a golf-cart based battery bank, with an MPPT and 48V inverter charger. You'd have a hell of a good charger for the golf cart then, plus you'd get to have your golf cart batteries do double duty. So you'd spec something like an XW 6048 with an MPPT instead of a grid-tied inverter. It seems like for the cost of a golf cart plus maybe $3k, you'd have a really nice emergency backup system and if you left the golf cart plugged in when you weren't using it, it could work pretty well.

    As an aside, I'm never putting my faith in a natural-gas powered emergency generator again. In an emergency, you should assume you'll have to be completely off grid, i.e. no natural gas either. Is having a diesel tank annoying? Yup. And is the diesel genny more expensive? Yup. But it should be a lot more fail safe.
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Flood relief off grid solar

    why not go a bit simpler, 48 v inverter ($$), a MidNite classic 150, the GC battery (stock 48v), and you're off to the course every other day...2 carts will get you golfing every day. PV would be as needed to get those GC's charged in 5 (?) hrs depends on # of good sun hrs. What Ahr rating do they have?
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • BB.BB. Super Moderators, Administrators Posts: 30,497 admin
    Re: Flood relief off grid solar

    There are also "layered" prep too... Natural gas for "normal outages", propane/diesel/gasoline for short term/wide area outages, solar for long term/just enough for a few lights and a fridge (if needed) outage.

    I still like to use this as a planning guide too (rules of three). You are/can be dead if:
    1. 3 minutes without air
    2. 3 hours without proper shelter (storm/ice/heat)
    3. 3 days without water
    4. 3 weeks without food

    Many people (at least those in the city) are not really ready for 3+ days without water.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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