OP
handirifle
Veteran Member
Not sure what company you mean except maybe for the system that was too pricey? Couldn't tell you what equipment they were installing. Not sure what the square flex is.
Thinking of a solar back up for well pump
- Thread starter handirifle
- Start date
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OP
handirifle
Veteran Member
If the sq flex is a solar panel, I have read flexible panels are less effecient. I know they do better in partial sum but with over 300 days of sun a year, thats not a big worry.
jenkinsph
Super Star Member
If I were trying to get by during a power outage using batteries for a power source I would use the rv as it would require less power to function.
For a fresh water pump using your storage tank I would use an rv 12 volt pressure pump with automatic on off control. A single 12v deep cycle battery group 29 would deliver a lot of water for your use. It may not produce as much as you are accustomed to but you could learn to live with it. Pump, battery, battery box and charger would cost about $250 to $300.
I don't see how your math works for the storage batteries. Most deep cycle batteries should not be discharged below about 50% and that cuts the available power in half. Some of the expensive batteries such as Odyssey Extreme are made to discharge to 80% so more power available between charges. In short terms you need a real battery bank to supply a 4000w inverter if you intend to run pumps for hours a day instead of minutes per day. Trojan batteries come to mind and they are not cheap. 4000w /12v=380 amp load with inverter losses included. So the 175 amp hour battery bank you mentioned would last maybe 10-20 minutes before the voltage dropped below 10 volts.
Just my opinion and I have looked into providing mobile power in my work for long duration times the cheapest way to power 230 v pumps is using a diesel generator. My reasoning for this is because batteries are expensive and require replacement frequently enough to make the systems operating cost too high. Natural gas pipelines may be shut down during a major fire. Gasoline does not store well and large quantities are unsafe to have around a home.
For a fresh water pump using your storage tank I would use an rv 12 volt pressure pump with automatic on off control. A single 12v deep cycle battery group 29 would deliver a lot of water for your use. It may not produce as much as you are accustomed to but you could learn to live with it. Pump, battery, battery box and charger would cost about $250 to $300.
I don't see how your math works for the storage batteries. Most deep cycle batteries should not be discharged below about 50% and that cuts the available power in half. Some of the expensive batteries such as Odyssey Extreme are made to discharge to 80% so more power available between charges. In short terms you need a real battery bank to supply a 4000w inverter if you intend to run pumps for hours a day instead of minutes per day. Trojan batteries come to mind and they are not cheap. 4000w /12v=380 amp load with inverter losses included. So the 175 amp hour battery bank you mentioned would last maybe 10-20 minutes before the voltage dropped below 10 volts.
Just my opinion and I have looked into providing mobile power in my work for long duration times the cheapest way to power 230 v pumps is using a diesel generator. My reasoning for this is because batteries are expensive and require replacement frequently enough to make the systems operating cost too high. Natural gas pipelines may be shut down during a major fire. Gasoline does not store well and large quantities are unsafe to have around a home.
OP
handirifle
Veteran Member
jenkinsph
I get what you are saying but it would never be under a full load, as you described, but for more than a fraction of a second. During motor startup. If you read my posts carefully, you'll see it would rarely, if ever need to run the well pump, which would be the 2hr run.
My point is to avoid moving into the RV. If it were going to be a LONG term issue, that might have to happen but if I can get by for a few hours or few days without it, then I would. I also cannot fill the water tank on the RV without pressure, as it is not a pour in opening, it's a regular hose connection, requiring pressure to fill. So it would mean getting pressure somehow, or storing the fresh tank full for months on end, with the possibility of it getting bad.
Even if the system only gave me one hour total of run time, it would most likely suffice.
As for generators, even storing diesel fuel can cause issues. The crud in diesel fuel can gel and cause major problems. I know cause it has when I store it for my truck and tractor. If I went generator, it would be a dual fuel (gasoline and propane) and be connected to a spare 120 gallon tank I have. I just don't want to have to turn on a generator to wash my hands, or leave it running all day. That is the negative of a generator, it is not demand friendly.
I have no desire to walk 30 yards up a hill, in the middle of the night so I can flush a toilet.
I also thought of other ways by running a smaller 110v pump and using existing generators or batteries, but a 110v motor is less efficient and uses just about as much juice. The only advantage is a cheaper inverter. A large enough 12v pump is a closer solution, one worth considering, as it would eliminate the need for an inverter.
I get what you are saying but it would never be under a full load, as you described, but for more than a fraction of a second. During motor startup. If you read my posts carefully, you'll see it would rarely, if ever need to run the well pump, which would be the 2hr run.
My point is to avoid moving into the RV. If it were going to be a LONG term issue, that might have to happen but if I can get by for a few hours or few days without it, then I would. I also cannot fill the water tank on the RV without pressure, as it is not a pour in opening, it's a regular hose connection, requiring pressure to fill. So it would mean getting pressure somehow, or storing the fresh tank full for months on end, with the possibility of it getting bad.
Even if the system only gave me one hour total of run time, it would most likely suffice.
As for generators, even storing diesel fuel can cause issues. The crud in diesel fuel can gel and cause major problems. I know cause it has when I store it for my truck and tractor. If I went generator, it would be a dual fuel (gasoline and propane) and be connected to a spare 120 gallon tank I have. I just don't want to have to turn on a generator to wash my hands, or leave it running all day. That is the negative of a generator, it is not demand friendly.
I have no desire to walk 30 yards up a hill, in the middle of the night so I can flush a toilet.
I also thought of other ways by running a smaller 110v pump and using existing generators or batteries, but a 110v motor is less efficient and uses just about as much juice. The only advantage is a cheaper inverter. A large enough 12v pump is a closer solution, one worth considering, as it would eliminate the need for an inverter.
Redneck in training
Elite Member
You can use VFD (variable frequency drive) programmed for a ramp start of the pump. That way you could get by with smaller inverter. They are cheaper than large inverter
OP
handirifle
Veteran Member
I will have to research that one. Thanks
jenkinsph
Super Star Member
Here is a link to the Grundfos MQ pumps I have used and sold. They work pretty well and are soft start. These would still require a good power source though. http://us.grundfos.com/products/fin...oads/download_2/file/file.res/L-DWS-SL-02.pdf
For your needs I would still recommend a 12v rv pump and get by with that.
To run the existing 230v pump you speak of with 8 amps running that is still a 153 amp load at 12volts. That is a heavy load on a battery bank rated for 175 amp hours, too much in my opinion. If you must run these larger pumps I recommend you up the battery storage by about 5 times to 750 =1000 amp hours.
OP
handirifle
Veteran Member
Well, personally 750-1000 to my thinking is way overkill. Would have been cheaper to go with the commercial bid, than hobble that together.
I have done some more reading and will post what I decide to build. One idea that caught my attention, was a guy that had a bank of batteries and used a 110v trickle charger to maintain them. Then he just ran them till they dropped off. I could recharge them with solar or a small generator. A second, smaller 110v pump was my very first, original idea, even a few years ago, that I could power with a generator, but I shelved the idea because I didn't want a generator running all the time.
I have done some more reading and will post what I decide to build. One idea that caught my attention, was a guy that had a bank of batteries and used a 110v trickle charger to maintain them. Then he just ran them till they dropped off. I could recharge them with solar or a small generator. A second, smaller 110v pump was my very first, original idea, even a few years ago, that I could power with a generator, but I shelved the idea because I didn't want a generator running all the time.
RNeumann
Elite Member
The solar/battery "need" is always difficult. The time of year/weather and uses are factors that only you can decide. Of course the power will go out on a stormy....yada yada yada.
Remember inverters are only 70-80% efficient. You will lose a lot right there. Also consider the amp hours for the draw. At higher draws you EXPONENTIALLY less usable power in the battery- batteries can only make power so fast. A factor for battery type and size.
It may be cheaper to figure a way to backfeed the well circuit or panel with the existing system. Maybe an extension cord or something similar. A dedicated system doesn't seem to be the best approach.
If it was me I'd add a hand pump to the well. They sit next to the existing pipe and can run a shower etc just fine. You typically back feed the plumbing via a hose bib. Their is a company in North Idaho that makes a nice one.
Remember inverters are only 70-80% efficient. You will lose a lot right there. Also consider the amp hours for the draw. At higher draws you EXPONENTIALLY less usable power in the battery- batteries can only make power so fast. A factor for battery type and size.
It may be cheaper to figure a way to backfeed the well circuit or panel with the existing system. Maybe an extension cord or something similar. A dedicated system doesn't seem to be the best approach.
If it was me I'd add a hand pump to the well. They sit next to the existing pipe and can run a shower etc just fine. You typically back feed the plumbing via a hose bib. Their is a company in North Idaho that makes a nice one.
OP
handirifle
Veteran Member
As I mentined before, the well is almost 600ft from the tank. This boy ain't pumping no hand pump.
