Pressure pump using battery backup

We have a full time off grid home with a 500' deep well.  Currently we have a soft start Grundfos 5SQ-410 pump that runs at 6.6 gallons per minute into three pressure tanks for a total of 98 pressurize gallons .  It takes just over 15 minutes of running to pressurize the house at 30/50# of pressure.  The problem is the well pump comes on at night which really hammers our batteries.  The current well pump draws 11.2 amps and shows about 2.5 kw while running.  I'm thinking of going to a 1000 gallon cistern with a smaller pressure pump so that it can run at night if needed.  I will have the solar to use the well pump during the day to pump into the cistern.  By the way, our household uses 230-260 gallons of water per day and our elevation is 8,600'.   The options I have are as follows: 1)I've found a Grundfos JP05D-CI jet pump that is 1/2 hp and is rated at 3.61 amps at 115v or 7.06 amps at 230v that pumps at 12.5 gallons per minute and uses about 770 watts while running.  It is not a soft start pump but will pump up my 98 gallon pressurized tanks in just under 8 minutes which will save some power.  
Option 2) is a Grundfos scala2 "on demand" pressure pump that would not need the pressure tanks I currently have in place.  It would power up every time you open a water valve or flush a toilet.  This pump can be plugged into a 115v outlet and uses 5.7 amps and pumps at a rate of 13 gpm and uses about 550 watts while running.  It has a variable smart control that "learns" your plumbing to control speed and power necessary to maintain a pressure you select up to 60#.  
So, my question is which of these two alternative would offer the least impact on the health of my battery bank?  Or do you have a recommendation for a pump or setup that will reduce my battery usage in the evenings?
Thanks for any info you are willing to share.

I have a 6 gpm grundfos sqflex, its wired to 1000 watts of monocrystaline panels at 200 v DC. I leave it on all the time. It pumps to a 500 gallon tank that is open to the atmosphere, no pressure. Overflow from that tank runs to a pond. So everyday my tank is full and I pump 3000 ish gallons a day. From the 500 gallon static tank I have a shureflo on demand pump plumbed to a 20 gallon pressure tank. This gives us about 40ish psi of water pressure.  This pump runs off my solar system from the house. Seems to be pretty efficient but noisy.  What I think would be an ideal system and I will do when my shure Flo pump goes bad, is buy just a cheap 110 v a.c. well pump, they can be had on Amazon for less then 200 bucks. I would just lay the pump in the bottom of my 500 gallon static tank, and plumb it to the pressure tank and place a pressure switch on the pressure tank that runs the pump.  Since your not requiring your well pump to pump into pressure it should be very easy on that pump, and the 110v pump in the static tank does not have to overcome 150 ft + of head pressure on it(depending on static water level), so I think you could run the pressure 50 60 psi easy and not be too hard on the pump. I feel like it would be a quiet robust system, and really pretty efficient.  As you've found, the hardest part is getting the water out of the 500ft hole. Storing it on the surface is a better idea not only for efficiency for your batteries, but in case of mechanical break down.  My friends well pump just quit. He had to come borrow water from me. If mine quits, I have a 500 gallon reserve to deplete to give me time to fix it.   You could buy a new 1000 gallon septic tank and bury it, it would never freeze. My tank is in my shop.

Eric Hammond wrote:I have a 6 gpm grundfos sqflex, its wired to 1000 watts of monocrystaline panels at 200 v DC. I leave it on all the time. It pumps to a 500 gallon tank that is open to the atmosphere, no pressure. Overflow from that tank runs to a pond. So everyday my tank is full and I pump 3000 ish gallons a day. From the 500 gallon static tank I have a shureflo on demand pump plumbed to a 20 gallon pressure tank. This gives us about 40ish psi of water pressure.  This pump runs off my solar system from the house. Seems to be pretty efficient but noisy.  What I think would be an ideal system and I will do when my shure Flo pump goes bad, is buy just a cheap 110 v a.c. well pump, they can be had on Amazon for less then 200 bucks. I would just lay the pump in the bottom of my 500 gallon static tank, and plumb it to the pressure tank and place a pressure switch on the pressure tank that runs the pump.  Since your not requiring your well pump to pump into pressure it should be very easy on that pump, and the 110v pump in the static tank does not have to overcome 150 ft + of head pressure on it(depending on static water level), so I think you could run the pressure 50 60 psi easy and not be too hard on the pump. I feel like it would be a quiet robust system, and really pretty efficient.  As you've found, the hardest part is getting the water out of the 500ft hole. Storing it on the surface is a better idea not only for efficiency for your batteries, but in case of mechanical break down.  My friends well pump just quit. He had to come borrow water from me. If mine quits, I have a 500 gallon reserve to deplete to give me time to fix it.   You could buy a new 1000 gallon septic tank and bury it, it would never freeze. My tank is in my shop.

Thanks for that reply.  I do have space in my workshop for the 1000 gallon tank and the year round temp in there is 56-60 F so it will work.  Trying to bury anything on this granite rock out cropping I built on is costly.  I will look into that cheap well pump as a solution as I want to most efficient one I can get.  Wish I had put in the 6sqf originally, but it's too late for that now.  Just need to figure out how to store solar in water and pressurize the house.  Thanks again.

I've done tons of research into solar well pumping, as I'm sure you've found there are very very few of us ACTUALLY doing it, so I was super excited to see your post!  If you need anything, let me know. I've spent a ridiculous amount of money on water, but I finally feel like I have a system that works for me and my family.

Best of luck!

I like the cistern and booster pump from pv direct well source approach and have installed solar powered systems similar to both, your and Erics systems.

What size is your battery?
How much of your water is pumped at night?
Inflexible time of use?

The reason i ask, is you already have a super well pump for operation off grid.

It looks like about 65-70 amp hours to run for one hour or 52ish amps plus losses could be as high as 70amps effectively. Gallons per watt is gallons per watt.

Thats 98 gallons or however many you use plus recovery, it varies with gpm delivered vs time and full volume of a pressure tank is not delivered to your taps. There is a spec., and if you have three of the big boys and assume 98 gallons delivered plus run time while full, if any.

Its still not a whole lot of power in watt hours and if its too high a draw in amps to come on once or twice over night and you did not want to shift time of use (cheapest method, highest efficiency), then your battery is experiencing this during the day, some days anyhow.

Your whole household power system will likely benifit from a larger battery as if you use that much water after sundown, i would suspect higher levels of power use for lights, towel heaters, entertainment/communications, cooking, hobby, laundry and whatever else you may doing.

The cost and building constraints of all of the upfit and installation required for a two pump system should be weighed against the same for a battery upgrade.

The battery upsize in amp hours and or retrofit to lithium or other tech allowing higher amp draws per amp hour of capacity has benifits aside from gallons of water delivered after sundown. My guess would be greatly improved battery service life if you are undersized now.

Erics system is one of the best configurations for keeping amperage from battery storage/inverter watts down in a common residential situation.

The battery is usually the step-child component!

Eric Hammond wrote:I've done tons of research into solar well pumping, as I'm sure you've found there are very very few of us ACTUALLY doing it, so I was super excited to see your post!  If you need anything, let me know. I've spent a ridiculous amount of money on water, but I finally feel like I have a system that works for me and my family.

Best of luck!

I found this well pump on Amazon which looks pretty good for what I want:  https://www.amazon.com/gp/product/B01A7S4Q0Y/ref=ox_sc_act_title_1?smid=A1Y4RBJHD0SC34&psc=1

It's rated for 25gpm, and with the cistern to the pressure tanks I'm only lifting the water about 7 feet so it shouldn't run for very long and with low amps.

Johnny Ainsworth wrote:

Eric Hammond wrote:I've done tons of research into solar well pumping, as I'm sure you've found there are very very few of us ACTUALLY doing it, so I was super excited to see your post!  If you need anything, let me know. I've spent a ridiculous amount of money on water, but I finally feel like I have a system that works for me and my family.

Best of luck!

I found this well pump on Amazon which looks pretty good for what I want:  https://www.amazon.com/gp/product/B01A7S4Q0Y/ref=ox_sc_act_title_1?smid=A1Y4RBJHD0SC34&psc=1

It's rated for 25gpm, and with the cistern to the pressure tanks I'm only lifting the water about 7 feet so it shouldn't run for very long and with low amps.

Hey, thanks for you input.  There are always constraints with any energy system and it's taken me a while (9 years) to understand the dynamics of how to best optimize the constraints so that things run relatively smoothy.  That being said, there are some things I am now changing and will change as time goes on.  First, when I replace this current lead/acid battery bank, I will be going to a NiFe battery setup of some kind, though hopefully that will be a few years down the road.  Currently, I have 24 2v Trojan L16RE-2V that have been in service since October, 2013.  I'm using on average 16.02 kWh per day, my solar is producing 14.198 kWh per day and the balance has been generator run time, this over the past 2 months.  We are at 8600' elevation in Colorado and the last couple of months have been unusually cloudy.  My biggest energy uses are our well pump, then our refrigerator which uses 1.96 kWh per 24 hours, then my mother in laws inverter refrigerator which uses .75 kWh per 24 hours, then our small freezer which uses .52 kWh per 24 hours, then our Dish network receiver which uses .50 kWh for 5 hours per day!  We have in floor heat which is supplied by 5 Grundfos Alpha pumps which use about 14-20 watts each all the time.  Our heat is from our outdoor wood furnace which is great, but we do have a propane furnace as back up.  What has been happening was that our well pump was running at least one time at night (after sunset and before we start getting solar generation) and sometime more.  Well it takes about 15 minutes for it to pump up our pressure tanks so it's pushing our battery voltage from about 48.6v down to 46.4v when I've watched it.  If the batteries didn't absorb or float the evening before the readings are 47.6v to 45.6 volts which means my batteries are essentially empty.  Now, in the ladder case, when the well pump turns off, the voltage climbs back up to 47.6v before the sun comes up.  So, what I did several months back was to set my generator on a Load start between the hours of 4pm and 7am so that if the well pump comes on, the generator starts after 2 minutes and runs until 4 minutes after the well pump load ends.  That has helped a lot, but it is using a lot of propane since we have an oversized generator or 12kw (another thing I would have changed though at 8600' elevation it does compensate for the derating due to elevation).  Anyway, the next thing I'm adding right now are more solar panels.  The original panels consisting of 12-190watt panels in 2008 and 4-220 watt panels (2013) only supply about 1/2 of the power needed for my 24 Trojan batteries (2013) which is a big part of my problem.  I am about to install another 9-300watt panels on another FlexMax 80 Charge controller that will give me plenty of solar generation. So, to take advantage of that and to keep heavy loads off of our batteries during the night, I am going with a 1000' water cistern so that I can run the heavy loadwell pump during the day to "store" solar in the form of water for the night or multiple days in case we have snow for a couple of days.  

Nice details. 1100ish ah @48v  and 80% dod 42kwh! 26kwh@ 50% dod. You seem to have enough experience, observation and decent equipment. True, pv watts are way low for that battery, still 3000 watt hours is 3000 watt hours and that 10whr per gallon.... the pump draw is 1/16 battery capacity nameplate, not bad.

One of two things, or both. I would do a countdown of capacity in amp hours actual usable without charging. If you do not get appropriate numbers, you have degraded capacity. Your system monitor may have a setting for actual capacity correction to soc read.

The battery voltage when the generator starts for protection or the inverter disconnects under a voltage setpoint at a setpoint in soc or projected voltage for soc is usually load compensated and is a better measure if so. I install these for a living and still have to force myself to ignore operating battery voltage for actual condition.

This stuff IS expensive and i still cringe, even though i know better. A quick specific gravity measurement at the condition/times you detailed would serve as proper confirmation related to your dasboard readings as a reference. Less cringe!

Soc is soc regardless of battery voltage with a load and .5v is alot of watt hours for you. 50-75amps from a healthy battery of that size should not be a problem unless its old or cold, especially with a duration of 15 minutes.

We are lucky to be able to run a 1/2hp pump and have excellent service, shift time of use to avoid multi load laundry to daytime hours and shut down our refrigerator in november to febuary, no generator.

This will not work for most. The overlap of our pump and washer is 1440w, this causes no issues at 440ah/24v and a load of laundry is about 550whr. Our capacity vs yours is about 20% and pump load, less than half, all things being equal, you should have no damage from your use.

Still, with 1100ah, it is a 1.5-2 day battery without input at your consumption rate. 2200ah equivalent to flooded lead acid when sizing for NIFE would likely serve nicely.

Some just let the generator cover it.
I would rather adjust usage to avoid even owning a generator, not doable for most, and not suggested for a battery investment of your size. I install that capacity and that battery at about half of our residential of grid sites, so far no issues as long as consumption or habits do not change drasticly from my recommended 8-10kwh daily and oversize arrays.

Thanks for the data on your scenario, it helps our education.

[quote=frank li]Nice details. 1100ish ah @48v  and 80% dod 42kwh! 26kwh@ 50% dod. You seem to have enough experience, observation and decent equipment. True, pv watts are way low for that battery, still 3000 watt hours is 3000 watt hours and that 10whr per gallon.... the pump draw is 1/16 battery capacity nameplate, not bad.

One of two things, or both. I would do a countdown of capacity in amp hours actual usable without charging. If you do not get appropriate numbers, you have degraded capacity. Your system monitor may have a setting for actual capacity correction to soc read.

The battery voltage when the generator starts for protection or the inverter disconnects under a voltage setpoint at a setpoint in soc or projected voltage for soc is usually load compensated and is a better measure if so. I install these for a living and still have to force myself to ignore operating battery voltage for actual condition.

This stuff IS expensive and i still cringe, even though i know better. A quick specific gravity measurement at the condition/times you detailed would serve as proper confirmation related to your dasboard readings as a reference. Less cringe!

Soc is soc regardless of battery voltage with a load and .5v is alot of watt hours for you. 50-75amps from a healthy battery of that size should not be a problem unless its old or cold, especially with a duration of 15 minutes.

We are lucky to be able to run a 1/2hp pump and have excellent service, shift time of use to avoid multi load laundry to daytime hours and shut down our refrigerator in november to febuary, no generator.

This will not work for most. The overlap of our pump and washer is 1440w, this causes no issues at 440ah/24v and a load of laundry is about 550whr. Our capacity vs yours is about 20% and pump load, less than half, all things being equal, you should have no damage from your use.

Still, with 1100ah, it is a 1.5-2 day battery without input at your consumption rate. 2200ah equivalent to flooded lead acid when sizing for NIFE would likely serve nicely.

Some just let the generator cover it.
I would rather adjust usage to avoid even owning a generator, not doable for most, and not suggested for a battery investment of your size. I install that capacity and that battery at about half of our residential of grid sites, so far no issues as long as consumption or habits do not change drasticly from my recommended 8-10kwh daily and oversize arrays.

Thanks for the data on your scenario, it helps our education.
[/quote]

Frank,
Thank you for the detail analysis of my system.  I agree with you on this and I'm pretty certain I've lost some capacity.  Just so you know, I've never had SOC activated gen start or a low voltage gen start and I have those set at the appropriate set points.  I am conservative on my absorb set point and time along with the float time with the absorb set point at 57.2 for 1 hour and the float at 54.0 for 1 hour.  Realistically, I can't go any further than that during this time of year.  In the summer, I've floated for as long as 3 hours.  With the addition of the new panel array, I should be able to absorb for 2 hours and float longer.  Also, I do not equalize...ever.  I would be interested in your thoughts on that.  Typically, if I don't absorb or float for three days, I will run the generator to get to the float stage.  

As an Australian I am surprised at the depths you are going to for water.
Here we mainly catch it off roofs, I store about 300,000 Litres in tanks.
Is such a thing possible for you, my rainfalls 450 mm [18 inches] per annum

John C Daley wrote: As an Australian I am surprised at the depths you are going to for water.
Here we mainly catch it off roofs, I store about 300,000 Litres in tanks.
Is such a thing possible for you, my rainfalls 450 mm [18 inches] per annum

There are certainly locations in the U.S. that have significant rainfall amounts like yourself, but we live at 8600' elevation in what is known as a high desert mountain area between two ranges of mountains.  Our rainfall is likely less than 20" per year and our snowfall is about 80" per year.  We do have a creek about 300' below our home, but due to the water laws of Colorado, it is not usable for us.  I do catch snow melt off of our roof for garden irrigation and am contemplating using our grey water for the same.
By the way, originally we drilled 650' for water and got only 3/4 gallon per minute.  We lived with that for about 3 years until it went dry, then fracked the well an now have an acceptable flow of 5gpm.  When we fracked the well, some of the rock dislodged and now our well is estimated to be about 550' deep.  Our pump is at 500'.
Have a Happy New Year!

Man I'm glad I don't live in Colorado, I just glanced through their water rights laws, what a mess.  Did you know that while you are now allowed to capture rainwater from your roof, you're only allowed to store 2 barrels (110 gallons) worth of it?  That's kind of pointless.

You mentioned a creek.  While it might be to difficult to get rights to the water in the creek, is it suitable for a micro-hydro setup?  New federal laws make it much easier to get permits for micro-hydro installations.

I'd go to the 1000 gallon tank and put a clock on the well pump so that you don't pump at night. If you're using 260 gallons a day you're only drawing down 25% during the entire 24 hours. At night I'd guess your water usage is less than during the day. Even if the usage is the same at night you'd be down 13% by morning.

Shoulda thought that one out longer. Seems like you need a larger well pump tank, or put any tank between your well pump and your house plumbing. Think of your hot water tank. It's in the line between your pump and your faucets. It's pressurized like anything else in your plumbing system. Any tank you put in the plumbing system will pressurize as well. So you need a larger tank and a timer that allows your deep well pump to run during the day.

John Duda wrote:Shoulda thought that one out longer. Seems like you need a larger well pump tank, or put any tank between your well pump and your house plumbing. Think of your hot water tank. It's in the line between your pump and your faucets. It's pressurized like anything else in your plumbing system. Any tank you put in the plumbing system will pressurize as well. So you need a larger tank and a timer that allows your deep well pump to run during the day.

I have a tankless hot water heater with a heat exchanger in front of it from the Outdoor Wood Furnace.  The configuration we have set up now worked until we added another person to the household and it was just enough to make it inefficient.  So, yes a 1000 gal cistern is in the works with a time as you suggest to pump only during the day.  I've also thought about a solar relay so that it won't pump on cloudy days.  I'll need to research that a bit more.

Peter VanDerWal wrote:Man I'm glad I don't live in Colorado, I just glanced through their water rights laws, what a mess.  Did you know that while you are now allowed to capture rainwater from your roof, you're only allowed to store 2 barrels (110 gallons) worth of it?  That's kind of pointless.

You mentioned a creek.  While it might be to difficult to get rights to the water in the creek, is it suitable for a micro-hydro setup?  New federal laws make it much easier to get permits for micro-hydro installations.

Yes, the water "rights" in Colorado are archaic.  While we account for much of the snow melt in the lower 48, we send it to California and Kansas while we have to account for every drop we use to ensure we don't violate our well permits.  

It's my opinion that the water that people and plants use winds up back in the soil. There's some evaporation of course. But the water that falls on my roof should be my property to evaporate as I see fit. To say that I can't evaporate enough water to grow the food that I need to keep myself alive is beyond belief. When I was young the phrase "It's a free country" was commonly spoken. Today the most common phrase is "we need a safe place".

A man who doesn't have the right to grow his potatoes, has no rights.

[quote=Johnny Ainsworth][quote=frank li  education.
[/quote]

Frank,
Thank you for the detail analysis of my system.
-  I am conservative on my absorb set point and time along with the float time with the absorb set point at 57.2 for 1 hour and the float at 54.0 for 1 hour.  Realistically, I can't go any further than that during this time of year.  In the summer, I've floated for as long as 3 hours.  With the addition of the new panel array, I should be able to absorb for 2 hours and float longer.  Also, I do not equalize...ever.  I would be interested in your thoughts on that.  Typically, if I don't absorb or float for three days, I will run the generator to get to the float stage.  [/quote]

Trojan uses 59.28v as the absorb voltage. Some battery makes have a range of suitable voltages indicated. I do tend to roll back a bit of i notice excessive water use or other signs of over-charging, sometimes it is capacity loss or other damage.

This depends on how a battery is used in a system, they are sometimes quite different. I will generally set up systems in the top 10% range of voltage settings, in the case of trojan, it says 59.28, i set 59.28 or closest increment and the owner will monitor from there.

22amps end amps setting, 10-12hr absorb, float constant 54v and lower time setting to avoid excessive water consumption... 'circ pumps run all the time'.  You will not likely absorb for 10 hours, the.setting makes sure accumulated time at the absorbtion voltage is ample to charge to full. End amps, if your controller has it, is a better indication and limit.


Standing loads and on low input days, should be floated with pv if possible, and without a high rebulk setting. Not usually gonna float at all on the generator for battery charging, unless its shoptime or other load based operation and float time is available.
 
Sufficient daily discharge and Pv charging capacity with upper range points and times not exceeding manufacturer suggested voltages will help reduce the need to equalize a well connected battery.

If there is a disparity in specific gravity from cell to cell, equalization is required.

In my personal system, I equalize once or twice a year. I water approx 2 times per year(,charge to full, water, charge to full, equalize 1 hour, check water.)

Some of the systems i maintain use more, but require higher charge-discharge rates, and use more water as a result.

Generator/ inverter-charger should run a bulk charge to the absorb setpoint if you can bridge it on solar. Charge through to 75-80% soc or 80% of absorb time and higher end amps generally and only go through a complete charge cycle (still 0 float time), if it has not been charged to full in a couple weeks and it doesnt look like it will soon.

It sounds like you have operated successfully with your settings, so i would ask the same of you about your experience, running that profile.

I generally back off a little on specified max charge amps for all batteries and avoid excessive pv float times and voltages if not in daily use.

I think raising your absorb voltage and equalizing will probably recover some capacity by charging fully, as long as there is no permanent damage. I doubt it would hurt anyway, but if specific gravity is good, you technically should not need to equalize.

[quote=frank li][quote=Johnny Ainsworth][quote=frank li  education.
[/quote]

Frank,
Thank you for the detail analysis of my system.
-  I am conservative on my absorb set point and time along with the float time with the absorb set point at 57.2 for 1 hour and the float at 54.0 for 1 hour.  Realistically, I can't go any further than that during this time of year.  In the summer, I've floated for as long as 3 hours.  With the addition of the new panel array, I should be able to absorb for 2 hours and float longer.  Also, I do not equalize...ever.  I would be interested in your thoughts on that.  Typically, if I don't absorb or float for three days, I will run the generator to get to the float stage.  [/quote]

Trojan uses 59.28v as the absorb voltage. Some battery makes have a range of suitable voltages indicated. I do tend to roll back a bit of i notice excessive water use or other signs of over-charging, sometimes it is capacity loss or other damage.

This depends on how a battery is used in a system, they are sometimes quite different. I will generally set up systems in the top 10% range of voltage settings, in the case of trojan, it says 59.28, i set 59.28 or closest increment and the owner will monitor from there.

22amps end amps setting, 10-12hr absorb, float constant 54v and lower time setting to avoid excessive water consumption... 'circ pumps run all the time'.  You will not likely absorb for 10 hours, the.setting makes sure accumulated time at the absorbtion voltage is ample to charge to full. End amps, if your controller has it, is a better indication and limit.


Standing loads and on low input days, should be floated with pv if possible, and without a high rebulk setting. Not usually gonna float at all on the generator for battery charging, unless its shoptime or other load based operation and float time is available.
 
Sufficient daily discharge and Pv charging capacity with upper range points and times not exceeding manufacturer suggested voltages will help reduce the need to equalize a well connected battery.

If there is a disparity in specific gravity from cell to cell, equalization is required.

In my personal system, I equalize once or twice a year. I water approx 2 times per year(,charge to full, water, charge to full, equalize 1 hour, check water.)

Some of the systems i maintain use more, but require higher charge-discharge rates, and use more water as a result.

Generator/ inverter-charger should run a bulk charge to the absorb setpoint if you can bridge it on solar. Charge through to 75-80% soc or 80% of absorb time and higher end amps generally and only go through a complete charge cycle (still 0 float time), if it has not been charged to full in a couple weeks and it doesnt look like it will soon.

It sounds like you have operated successfully with your settings, so i would ask the same of you about your experience, running that profile.

I generally back off a little on specified max charge amps for all batteries and avoid excessive pv float times and voltages if not in daily use.

I think raising your absorb voltage and equalizing will probably recover some capacity by charging fully, as long as there is no permanent damage. I doubt it would hurt anyway, but if specific gravity is good, you technically should not need to equalize.[/quote]

Thanks for that Frank. I check water levels every two months and will water as needed.  That usually means watering about every four months approximately 1-2 gallons for my batteries. Once I have the solar capacity with the new panels I will move the absorb point higher and longer for the winter.  I will also run a equalize cycle to see if that improves the output.

Great system details!  Based on what you have laid out your system is well designed although as you noted a little light on the solar.
When I look at your stats I come up with another idea. Can you split up your pressure tanks?  If you have valves at each tank try shutting one off at night. Ideally you will have shortened the pump runtime in half and lessened the hit your l16's are taking when they are at their most weakened. If a scenario like that works I might consider doing away with one tank completely or some solenoid valves on tank 2 for nightime shutout controlled by a timer. Yes you will create more run cycles on the pump but will probably add life to the batteries to compensate and will have minimal cost for new gear. If you switch to Nife batteries remember that their instantaneous discharge rate is lower then lead so size accordingly.
Cheers, David Baillie

David Baillie wrote:Great system details!  Based on what you have laid out your system is well designed although as you noted a little light on the solar.
When I look at your stats I come up with another idea. Can you split up your pressure tanks?  If you have valves at each tank try shutting one off at night. Ideally you will have shortened the pump runtime in half and lessened the hit your l16's are taking when they are at their most weakened. If a scenario like that works I might consider doing away with one tank completely or some solenoid valves on tank 2 for nightime shutout controlled by a timer. Yes you will create more run cycles on the pump but will probably add life to the batteries to compensate and will have minimal cost for new gear. If you switch to Nife batteries remember that their instantaneous discharge rate is lower then lead so size accordingly.
Cheers, David Baillie

David, thanks much for that well thought out solution.  I hadn't considered separating those tanks with a valve I could turn on/off and that will be a possible short term solution.  I have decided on the 1000 gal cistern with a Grundfos scala2 pump which should give us very good pressure along with modest impact on the batteries.  The way I am setting this system up will be to put a diversion valve from the well pump into the cistern and also a diversion valve from the new Grundfos into the house water supply so that I can run either if at some point in time I will need to do so.
Thanks for the heads up about the Nife batteries discharge rate.  I wasn't aware of that lower discharge rate.

Eric Hammond wrote:I've done tons of research into solar well pumping, as I'm sure you've found there are very very few of us ACTUALLY doing it, so I was super excited to see your post!  If you need anything, let me know. I've spent a ridiculous amount of money on water, but I finally feel like I have a system that works for me and my family.

Best of luck!

Eric,
I don't know if you kept up with the rest of the comments on the solar water setup.  I've decided on putting in a 1000 gallon cistern and will pump from my 600' well during the day which gives me some flexibility on which days to pump.  Inside the house, i am going to bypass my pressure tanks and install a Grundfos scala2 constant pressure pump which runs when you have a faucet running then turns off.  The Grundfos scala2 is a smart pump that is soft start, pumps only to pressure set and backs off power automatically once pressure, gpm, or energy levels are optimum.  The 115v pump uses between 5-5.7amps while running which is less than a 1/4 of my well pump was using.  Just wanted to hear your thoughts on this and what you are using.
Thanks,

1) Reduce how much water you use overall, thus reducing pump/battery usage (poop at work...toilet=50% of water usage, batch prep your meal/laundry on the weekend daytime)
2) Time shift your water usage to mostly day time, thus using more direct solar and less night time battery energy (I see some remote start washers)


a) Well Pump       (1gal/min=60gal/hr=240gal in 4hr. Some kind of auto-switch when the tank is filled/overflow, and a timer to only turn on during the day)
b) Tank               (250gal tank in the basement for manual operation in emergency, could be used to operate a radiant celling panel chiller in the summer)
c) Tank Pump      (make it DC powered directly from the battery bank, more efficient, 12gal/minute)