somebody double check these figures (sanity check)

KenMorganKenMorgan Registered Users Posts: 43 ✭✭
So after crunching kw/h numbers for what seems like over a year I came up with the following for my cabin:  my usage per month in the winter over the last three years was 200 kw/h per month this is due to occasional heat tape use for the water pipes when the temps dip hard  -20C (-4F)  at night.

I chose a 3.6kw array with a 600 a/h 48 vdc bank. winter peak solar hours are 3.5 for this area.  Solar controllers are morningstar ts60-mppt x 3,  and inverter is a MS4448PAE with BMK,/AGS. 

Currently we only go up on the weekends, and the only load while gone is a 4 cubic feet refrigerator and nothing else as the pipes are drained each week.   daily use works out to about 8 kw/h so I am hoping for enough battery and panel to cover at least 2 days without the diesel generator firing up, though my muddling away seems to indicate possibly three with very limited if any sun.  can anybody confirm these rough calculations? 

Sign me: a former Marine living on Fuji and muddling his way though life
18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
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Comments

  • petertearaipetertearai Solar Expert Posts: 454 ✭✭✭✭
    daily use 8kw  with only a fridge running ?
    1kw for fridge , what else is using power ?

    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • mike95490mike95490 Solar Expert Posts: 9,185 ✭✭✭✭✭
    Something is wrong.   I run a household, shop and we have 2 full size energy star fridges and a upright ES freezer.  2 laptops, garage door opener, water treatment, and use 7kwh a day.     Those mini-fridges have mini-insulation and that compressor runs way too much
    And maybe your inverter is sucking too much at idle
    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 ,

  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    edited December 2018 #4
    that was the average of the power bill from Tokyo electric for the winter months over the last three years.  while we are there my wife uses a kotatsu (heated mini table with a blanket that traps the heat) its nameplate says 750 watts.  That's from the time turned on until she stops using it so basically all waking hours as she does not shut off.  or the time that i am out cutting firewood and working in the shop (shop is currently 3p generator but lighting and 120 equipment just started on the solar system this month). 

    Now this is not running in the middle of the week, just the weekends and originally all lighting was 40 year old incandescent.....  I just installed all new fixtures and changed to led lights so i am hoping for that to help.  but the really big draw in the winter is the heat tapes.  back then i ran them from the time we arrived, until shut off.  I have since blocked off all of the access to under the house to include insulation, and the heat wraps are now on a timer to turn them on at 2330, and then off at 0730.  I also set the timer to run 45 minutes on and 15 off to help negate the usage.   We also now run wood stove only which keeps the forced air kerosene heaters off so that helps as well.  many changes since I started calculating this, and I am hoping that with the changes it will help bump up the available reserve for less than stellar solar production. 

    Understand i still have a line tied to the grid that runs through a transfer switch, but if this winter works out, that will be gone, and then replaced with a line from the generator instead.
    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    edited December 2018 #5
    shoot seems like my last edit erased all.  as i said we are only there on the weekends, but while there my wife runs a kotatsu (heated table) thats nameplate is like 750 watts, if both (kotatsu) are on full blast its 1500 watts. (this can run up to 8 or 10 hours. )  the heat tape while running is 1200 watts or soand was originally on 24-7 for the weekends we were there.  I have since taken some measures to help, by insulating the underside of the house, and blocking air flow under it by sealing (for the winter) the crawl spaces.  I also put the heat tape on a timer so that it only runs during the coldest hours (2300 to 0700)  I also replaced all the incandescent lights with LED's.  the monthly figure is directly form the bill from Tokyo power company, but that was the three preceding years before the changes in insulation etc.

    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • petertearaipetertearai Solar Expert Posts: 454 ✭✭✭✭
    without doing calks , on  a glance you need a bigger system .
     However if you have grid power , stick with that . Easeyer and far Cheaper !
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    well part of this is a proof of concept for stage two which is the disconnect.  if needed i will increase the panel and battery numbers.  got plenty of space here on the side of fuji to pop up another 20 panels if needed.  batteries are a consumable in this equation so the big question is if I have enough to keep the DoD  reasonable or not.  losing power in this region soon do to lack of people living here and the cost of private ownership of lines that will entail to keep power here.  (for japan this is the boonies)  and none of the younguns want to live this far out...I kinda like it, thought the wife is not quite so amenable to the idea  ;) 
    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • mcgivormcgivor Solar Expert Posts: 3,665 ✭✭✭✭✭✭
    The Kotatsu tables will demand so much energy making off grid unreasonable, unless money is no object, traditional tables used charcoal, are gas ones available ?  
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    edited December 2018 #9
    mcgivor said:
    The Kotatsu tables will demand so much energy making off grid unreasonable, unless money is no object, traditional tables used charcoal, are gas ones available ?  
    Sorry this is so disjointed, I tend to jump around a bit when explaining.  The system is in place and awaiting final wiring into the house panel via a transfer switch. 
    the above numbers were the peak of what we used originally prior to re-insulating, sealing the underside of the house and pipes, and changing to all LED lights.

    Look at photo I attached its a "hori" kotatsu  IE:  one that is sunken into a pocket.  so i insulated around it with the 1" thick foam blocks this, along with covering the entrances to under the house (see avatar and look at large openings under house (now covered)) to kill any air movement under the house has reduced the need so that we only use one of the heaters now.  Its three settings are 750, 550, and 350 watts respectively for one unit.  It originally used two of the heaters in the area where you put your legs so we have reduced the number to one or 750 watts max with the insulation.  The heat tapes also do not kick on as often as they need to drop to sub 5 c to turn on, and with the reduced air movement they do not turn on as often.   I am hoping that we can run it at a lower setting with the extra insulation as well, time will tell.  

    This system was basically the size system that the sponsor of this forum had as one of their turnkey setups according to the usage charts to what I would need (prior to re-insulating etc.) for the winter months. I added a slightly larger battery bank.                                                                                           .                

    The red thing is the heater and the rest is the surrounding frame work that extends under the house to allow your feet to dangle in the heated space.which is now all foamed in.

    The solar power system is basically a much larger copy of the system I ran in my camper for the last 3 years (500 watts @12 volts @ 400ah w/2000 watt inverter for boondocking here in japan.)  with the house now being 3600 [email protected] volts @ 600 ah w/4400 watt inverter.

    I guess that my next question for those of you used to using larger systems is battery wiring.  currently I have the 12 batteries wired in a series parallel setup so that it is 48 volts at 600 amp hours.  see system diagram below.  (disconects and fusing not shown in full)




    is there a better way to wire the batteries to the charge controllers?  currently one controller goes to each battery bank though they are tied together at the negative at the battery monitoring shunt, and at the positive at a bus bar that feeds the inverter
    would it be better to have all the positives from the controllers meet at the same busbar and then feed both the banks and the inverter?  or is it better to have them go directly to their respective battery banks?

    lastly how would I wire in another bank of batteries if I need to add more?  I purposely oversized the solar controllers so that i could add another 20 panels and not strain the system if needed, would I need to add 12 more, or could I add just four or eight and still get a balanced charge? currently 600 Ah so examples would be 800 ah at 48 VDC if I added 4 more.  batteries are 1 month old from factory so at the end of this winter they will be 6~7 months old...still not to late to add four or eight I think...thoughts?


    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • EstragonEstragon Registered Users Posts: 4,482 ✭✭✭✭✭
    Heating anything with electicity for any length of time off-grid, except as an opportunity load when batteries are full, is pretty impractical.  Increasing battery and solar capacity to handle such a load is possible, but expensive.

    If gas fired tables aren't available, or you don't want to replace the tables for other reasons (eg. sentimental value), maybe it would be possible to retrofit a gas or diesel fired hydronic heating system into the tables, or the floor below.  Something like this:
    https://www.eberspaecher-na.com/products/fuel-operated-heaters/product-selection/coolant-heaters/hydronic-s3.html

    This might also work as an alternative to electric heat tape for some or all of the water line?  
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    Estragon said:
    Heating anything with electicity for any length of time off-grid, except as an opportunity load when batteries are full, is pretty impractical.  Increasing battery and solar capacity to handle such a load is possible, but expensive.

    If gas fired tables aren't available, or you don't want to replace the tables for other reasons (eg. sentimental value), maybe it would be possible to retrofit a gas or diesel fired hydronic heating system into the tables, or the floor below.  Something like this:
    https://www.eberspaecher-na.com/products/fuel-operated-heaters/product-selection/coolant-heaters/hydronic-s3.html

    This might also work as an alternative to electric heat tape for some or all of the water line?  


    at one time I was considering a buried and insulated 8000 gallon heat reservoir using 10 or 12 of the japanese solar water heaters (used of course) to heat the tank through the summer to do something similar...

    ....then a squirrel ran by (I am kind of like a golden retriever)... and probably ADHD as well so I built a wood stove from scratch instead.  (One project at a time.)

    Though I still might do the whole heat reservoir in the future, though that would be next year or so....still need to figure out the calcs for that IRT gallons of water at what temp to provide floor heat and under house protection through the winter.  the idea was to bury a stainless tanker truck tank from a decommissioned fuel hauler and then insulate it with foam prior to burying and covering it and then using natural convection to move hot water up the pipes and under the house in the winter...the heaters will heat about 200 gallons a day to about 190f so to heat and keep heated a 6000 gallon tanker tank i was thinking about 5 of them running in the summer, and then five more to go online in the winter months to help keep the temps up.they are pretty efficient and provide houses even at fuji hot water through the year... but once again Squirrel so my mind has wandered again  :) 
    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • EstragonEstragon Registered Users Posts: 4,482 ✭✭✭✭✭
    I did propane heated infloor radiant as a supplement to woodstove.  It does a good job of taking the chill off the floor, which can be chilly because of stratification of stove heat.  It also does domestic hot water, with glycol solution heat loops heated via a heat exchanger.

    Output is a function of water temp, flow rate, pipe size, floor material, etc., but ~25 btu/hr/sq.ft. is a reasonable OOM guess.   I did mine with 16"O.C. spacing as it's just for supplemental heat.  If doing it again, I'd do closer for more even heating.

    I don't think natural convection would give enough flow, but it doesn't take a lot of pump to circulate.  I have 4 zone pumps plus HX pump, on-demand propane heater, and lights running easily on a 300w inverter.  I run it for an hour or two maybe a couple times/day to take the chill off.  Solar heat wouldn't work too well in my (mid-Canada) climate.  Seems like we haven't seen sun for weeks, and when we do it's brief and low in the sky.

    Your bank appears to be 3 strings in parallel.  Wiring would normally create the parallel connection close to the batteries (with string fuses in the case of > 2 strings), then a single (big) +/- wire to a breaker then +/- bussbars.  The controllers would connect (via breakers) to the busses.

    Adding battery string(s) is possible, but gets unwieldy.  Some strings end up getting better charged than others, so you have to monitor individual strings carefully.  If flooded, it also gets to be quite a chore checking SG and watering.   Generally it's best to get bigger cell, lower voltage batteries so you get your design capacity with one or two parallel strings.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • BB.BB. Super Moderators, Administrators Posts: 31,326 admin
    Ken,

    I found your post #4... Not sure why it ended up in the spam queue.

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Registered Users Posts: 4,482 ✭✭✭✭✭
    Reading post #4 has me wondering more about the heat tape.  The ones I'm familiar with are self-regulating, and run~3-5w/ft or so.  For it to run 1200w for the line implies it's running full out on a pretty long line (eg. 1200/5=240' line).

    Is the line insulated with the tape between the insulation and pipe?  If so, the tape should self-regulate down to what's needed to maintain just above freezing temp.  If the pipe isn't insulated, most of the heat will be lost to surrounding air (or water/ice).

    Is the line supplying water from a well or other downhill source?  If so, you may be able to pump to a holding or pressure tank, and let water drain back to source between cycles, which may reduce or eliminate the need to run heat tape.

    Just some thoughts
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mcgivormcgivor Solar Expert Posts: 3,665 ✭✭✭✭✭✭
    edited December 2018 #15
    With the 3 parallel battery strings a DC clamp on ammeter https://www.amazon.com/Best-Sellers-Industrial-Scientific-Clamp-Meters/zgbs/industrial/5011680011
    would make verification of current ballance a much simpler task, maintenance is important to avert supprises. The controllers outputs would probably be better connected to a common point on the busbar but spaced apart (negative and positive ) so as not to favor a single battery, for example both positive and negative connected in the center, same goes for the inverter connections. Understandably the diagram above may be a representation of actual layout, with 3 battery strings it's wise to have individual fuses for each string to the busbar, in case of a battery failure the fuse would prevent the other strings dumping all their current into one in fault, not a common thing to occur but a possibility.

    With  the TS60 's use the battery sence input at the same point as the output connections this will keep the controllers in sync with regards to transition voltage, having MS View software will be an asset, it allows finer adjustments and monitoring, if you don't already have it. 
    Just some thoughts.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    Estragon said:
    Reading post #4 has me wondering more about the heat tape.  The ones I'm familiar with are self-regulating, and run~3-5w/ft or so.  For it to run 1200w for the line implies it's running full out on a pretty long line (eg. 1200/5=240' line).

    Is the line insulated with the tape between the insulation and pipe?  If so, the tape should self-regulate down to what's needed to maintain just above freezing temp.  If the pipe isn't insulated, most of the heat will be lost to surrounding air (or water/ice).

    Is the line supplying water from a well or other downhill source?  If so, you may be able to pump to a holding or pressure tank, and let water drain back to source between cycles, which may reduce or eliminate the need to run heat tape.

    Just some thoughts


    originally this was built as a summer only cabin.  so the bottom of the house was totally open (it stands on a poured concrete 1 meter tall foundation).  I just enclosed this all this fall and I can tell you the heat tapes and the kotatsu heaters were working overtime.  the south face got all the wind and was wide open to make a wind tunnel under the house for cooling in the summer.  blocking it off really changed the metrics trust me.

    the japanese heat tape is set rate type, it gets hot and has thermostat that is outside insulation and turns on at 5 deg celecius and off at 15 degree celcius.  it was wasting energy when it did not need it that why i put it on a timer this year as well. 

    the run was not that long, but I had wrapped all of the pipes as they were all exposed.  total heat tapes were 10 wraps of varying lengths two for kitchen pipes, two for bathroom sink, one for hot water heater, one for toilet, two for shower, and two for bathtub.  shortest one was 9' and the longest run was 24'.

    the package they came in was in japanese kanji with some crappy pictographs so I wrapped them with 3/8" spacing and then wrapped them with the foam tape that was supplied.  found out that first year that they were supposed to have a 1/2"~3/4" spacing when I had very warm water come out of my cold water pipes. 

    I have since received (but not installed) a 80' roll of the the US style heat tape (heat trace) that they use for new construction in the area I am from (Indiana) according to it I need to lay it flat on the bottom fo the pipe tape into place and then insulate with foam noodles.  this is next springs project, so it should help immensely with power useage.


    (also found out there is a difference between heat "traces" and heat "tapes" with me currently having heat tapes which use more electricity, I will be replacing this spring with heat traces to shave off some more power)

    so LSS (long story short) you are all correct about the heat tapes useing way too much power and the Kotatsu, I am addressing both but the heat wraps will be next spring, gotta muddle through this winter as its already too cold to climb under and change the tapes for this year.
    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    edited December 2018 #17
    Estragon said: edited for space
    "Your bank appears to be 3 strings in parallel.  Wiring would normally create the parallel connection close to the batteries (with string fuses in the case of > 2 strings), then a single (big) +/- wire to a breaker then +/- bussbars.  The controllers would connect (via breakers) to the busses.

    Adding battery string(s) is possible, but gets unwieldy.  Some strings end up getting better charged than others, so you have to monitor individual strings carefully.  If flooded, it also gets to be quite a chore checking SG and watering.   Generally it's best to get bigger cell, lower voltage batteries so you get your design capacity with one or two parallel strings."

    Me:  so currently I have three 48 volts strings you suggest the larger 6 volt or 2 volt batteries?  that will have to wait until these die then as they are brand new.  I did see offers for 1000 ah 2 volt batteries   

      this.


    Is this the type you are suggesting?  they run 300/unit with a minimum order of 10.  I would need at least  24 of them.  thats still going to run about 10k shipped with all customs etc paid.  something that big I would prefer something i could water myself vice the AGM style.  they offer both, just not sure about how I would ship the battery acid etc if I went flooded.but hopefully thats 7 or 8 years down the road, if not then i will just have to pull the trigger when the time comes.


    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    mcgivor said:
    With the 3 parallel battery strings a DC clamp on ammeter https://www.amazon.com/Best-Sellers-Industrial-Scientific-Clamp-Meters/zgbs/industrial/5011680011
    would make verification of current ballance a much simpler task, maintenance is important to avert supprises. The controllers outputs would probably be better connected to a common point on the busbar but spaced apart (negative and positive ) so as not to favor a single battery, for example both positive and negative connected in the center, same goes for the inverter connections. Understandably the diagram above may be a representation of actual layout, with 3 battery strings it's wise to have individual fuses for each string to the busbar, in case of a battery failure the fuse would prevent the other strings dumping all their current into one in fault, not a common thing to occur but a possibility.

    With  the TS60 's use the battery sence input at the same point as the output connections this will keep the controllers in sync with regards to transition voltage, having MS View software will be an asset, it allows finer adjustments and monitoring, if you don't already have it. 
    Just some thoughts.


    so instead of the battery sense going to the plus & minus terminals of each string, they should be at the junction of the three strings?

    I have 100 amp T class fuses between each bank and the bus bar mounted 6 inches from the battery bank.  I have a 150 amp T class fuse going from the buss bar to the inverter along with a 300 amp disconnect.  the diagram does not show all of the disconnects and fuses, jsut the major components I had to source for the initial planning.


    Please folks keep the comments coming,  final hookup into subpanels are 10 days away.  I will still have the grid mains coming in as a back up, but I want them gone next year if possible.  the biggest hurdle i have left is hooking the diesel generator up with the magnum auto start.  My genset is 30 years old so I have to figure out the wiring as it has no provisions for remote start.  it has a standard key like you would see on a car, back for glow plugs and forward for start....fun times  :)


    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • mike95490mike95490 Solar Expert Posts: 9,185 ✭✭✭✭✭
    Well, it's already been mentioned, using lower voltage ( 6, 4, 2v ) batteries with higher capacity and only one string, will save you a lot of watering time.
     L-16 floor scrubber batteries are a choice, golf cart batteries are another option.
    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 ,

  • mcgivormcgivor Solar Expert Posts: 3,665 ✭✭✭✭✭✭


    so instead of the battery sense going to the plus & minus terminals of each string, they should be at the junction of the three strings?

    I have 100 amp T class fuses between each bank and the bus bar mounted 6 inches from the battery bank.  I have a 150 amp T class fuse going from the buss bar to the inverter along with a 300 amp disconnect.  the diagram does not show all of the disconnects and fuses, jsut the major components I had to source for the initial planning.


    Please folks keep the comments coming,  final hookup into subpanels are 10 days away.  I will still have the grid mains coming in as a back up, but I want them gone next year if possible.  the biggest hurdle i have left is hooking the diesel generator up with the magnum auto start.  My genset is 30 years old so I have to figure out the wiring as it has no provisions for remote start.  it has a standard key like you would see on a car, back for glow plugs and forward for start....fun times  :)



    The voltage sense wires if commoned to the same point will ensure the controllers follow each other more closely, one point worth adding is, that if remote temperature sensors are used they would all have to be at a single point as well, as different temperatures will offset voltage output. My suggestion is ask tech support at Morningstar, they will suggest the best arrangement, they are extremely helpful.

    The cost of off grid will far exceed grid even at a dollar per Kwh, perhaps double that when life expectancy of batteries and equipment are included. 

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • BB.BB. Super Moderators, Administrators Posts: 31,326 admin
    Just an FYI:

    mcgivor said:
    With the 3 parallel battery strings a DC clamp on ammeter https://www.amazon.com/Best-Sellers-Industrial-Scientific-Clamp-Meters/zgbs/industrial/5011680011

    MicGivor's link is very nice with lots of meters listed. However, not all meters in the list are DC Current Clamp type DMMs.

    For our solar power systems, I highly suggest you get the DC Current Clamp DMM/Meter (also usually does AC Current Clamp too).

    It is great to be able to just zero the DC current clamp meter (DC C.C. meters have "zero drift" and can require re-zeroing every few minutes) and clamp it on a cable to measure the DC (or AC) current flow.

    Many of the meters in the above link are AC current clamp meters with AC/DC volt meter functions too.

    For example, here are a couple of low/medium priced AC/DC Current Clamp DMMs:

    https://www.amazon.com/gp/product/B019CY4FB4
    https://www.amazon.com/gp/product/B07546L9RT

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    edited December 2018 #22
    mcgivor said:


    so instead of the battery sense going to the plus & minus terminals of each string, they should be at the junction of the three strings?

    I have 100 amp T class fuses between each bank and the bus bar mounted 6 inches from the battery bank.  I have a 150 amp T class fuse going from the buss bar to the inverter along with a 300 amp disconnect.  the diagram does not show all of the disconnects and fuses, jsut the major components I had to source for the initial planning.


    Please folks keep the comments coming,  final hookup into subpanels are 10 days away.  I will still have the grid mains coming in as a back up, but I want them gone next year if possible.  the biggest hurdle i have left is hooking the diesel generator up with the magnum auto start.  My genset is 30 years old so I have to figure out the wiring as it has no provisions for remote start.  it has a standard key like you would see on a car, back for glow plugs and forward for start....fun times  :)



    The voltage sense wires if commoned to the same point will ensure the controllers follow each other more closely, one point worth adding is, that if remote temperature sensors are used they would all have to be at a single point as well, as different temperatures will offset voltage output. My suggestion is ask tech support at Morningstar, they will suggest the best arrangement, they are extremely helpful.

    The cost of off grid will far exceed grid even at a dollar per Kwh, perhaps double that when life expectancy of batteries and equipment are included. 


    I disagree with that last statement, I have does a full cost analysis and even with accounting for prices rising on all components over a 10 year span I will have saved money/broken even.  over a 30 years span even with replacing major components i will save money
    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    Part of this is I did not buy products from the "big names" except for the inverter, and solar controllers.   Panels and batteries were straight from the manufacturer and much much cheaper that listed prices for the same items in the states.  If you want to know what factory makes Q cells, then research the particulars in china....they are very open in regards to finding out the info of who makes and sells to who.
    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • littleharbor2littleharbor2 Solar Expert Posts: 1,589 ✭✭✭✭
    BB. said:
    Just an FYI:


    For example, here are a couple of low/medium priced AC/DC Current Clamp DMMs:

    https://www.amazon.com/gp/product/B019CY4FB4
    https://www.amazon.com/gp/product/B07546L9RT

    -Bill



    I have both the Klein and Uni-T DC clamp meters. Like them both. The one thing I like the Klein meter more for is the magnet feature on the back of the unit, It will stay put on a metal surface. Otherwise the Uni-T unit is a great value and a nice slim, handy size.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mcgivormcgivor Solar Expert Posts: 3,665 ✭✭✭✭✭✭
    KenMorgan said:
    Part of this is I did not buy products from the "big names" except for the inverter, and solar controllers.   Panels and batteries were straight from the manufacturer and much much cheaper that listed prices for the same items in the states.  If you want to know what factory makes Q cells, then research the particulars in china....they are very open in regards to finding out the info of who makes and sells to who.
    Fully understand buying directly from the manufacturer, my purchase of LFP batteries directly from the manufacturer were a fraction of the cost of commonly available offerings, but given the option I would still choose grid power if it were available. This is subjective, if the infrastructure maintenance costs are passed on to the consumer skewering calculations, which I'm sure this are factored into your long term projections. Things  may be different, but in general terms, it's hard to compete with grid power, many will verify this. The loss of the first set of batteries within a year or two, is all too common, hence the advice of using  a single string of batteries  as opposed to parrallel strings. If however you have vast experience which supercedes the collective experience pool, continue with your quest, disregarding all advice, I'm delivering a message the way a "Marine " needs to hear it, blunt but to the point. No offense intended.

       
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • EstragonEstragon Registered Users Posts: 4,482 ✭✭✭✭✭
    FWIW, I also had an open crawlspace under the cabin, which I've now enclosed and insulated.  Height varies, but likely averages about the same 1m.  It's made a huge difference in moderating temps in both summer and winter.

    Changing to the self regulating heat tape/trace and foam noodle should help at lot.  I redid all my supply lines except the main to be contained inside the cabin using pex and sloped for ease draining down. The old copper stuff in the crawlspace was a mess anyway, having obviously been frozen a number of times.  Main supply drains back between fill cycles, so my only heat trace is where the line goes through ice as backup in case air pressure system fails to push water down far enough.

    Definitely wait for the (hopefully distant) demise of existing bank before thinking of replacement.  My comment was just to point out the challenge of going to more than a couple of strings.  Once you've addressed the excessive loads, you may find the existing works fine.

    Doing a breakeven on solar is tough when future grid cost assumptions are little better than a WAG.  If they're likely to stick with big ongoing maintenance/capex bills, having an option available makes some sense.  For the other stuff, figure ~8yrs for decent well maintained FLA batteries, 10yrs for electronics, 20-25yrs for panels/racking/breakers/wire etc.  Off-grid, that typically seems to work out to ~ $0.50 - $1/kwh.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭
    edited December 2018 #27
    The internet is a piss poor place to chat as it never shows your state of mind,  that or my english communications skills are slipping even worse then I thought  :smiley:   I just meant to say that I think with the current direction that the power company is taking in my area and the dropping cost of batteries and panels that I will be able to actually save money over the long run.  sorry if I sounded snippy,
    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭

    so this past winter was as follows... average temps were running about 20 degrees on average in the daytime and about 0 at night. Blocking in the bottom of the house however severely limited the need for the heat tapes. my avverage overnight drain on the battery bank was 18 percent with 82 percent remaining. I had three or four times when it dipped down to 70 percent remaining after 3 or 4 days of poor production. this was running the two fridges 24-7 as well as ceiling fan, LED lights, the occasional water pump and the weekly kerosene fan heaters (about an hour each) when we first arrived on friday nights. This was running the heat tapes on a 15 on 30 off setting through the coldest parts of the night. later after I had enough data i eventually stopped turning them on at all as it was maintaining just above freezing under the house 33 to 38 degrees depending upon time of day. i did keep the heat tapes for the on demand water heater going through the night though as they have a 12" section that is not under the house and is exposed to the elements. but I double wrapped them and they shared one piece of 3 foot heat wrap between them. about 1/4 of the way through the winter Ihad to ditch my old fridge as it did not like swaping between 100VAC/50Htz to 120 VAC/60Htz the few times I ran on mains to allow the batteries time to completely charge only did it once and the fridge crapped out. the new one has had no issues to date though and I have done it twice to it. now to see how it works in the summer.

    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭

    Ken, if you have mains power why did you not just let t he 4448 Inverter do the charging vs plugging the fridges into the Mains?

     
    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
  • KenMorganKenMorgan Registered Users Posts: 43 ✭✭

    West Branch currently to meet code I had to have a disconnect outside of the inverter that mechanically disconects 100%. So the mains go into the disconnect as does the inverter. I was demonstrating the disconnect to a friend when I fired the refrigerator....it was a small 80liter unit that was about 25 years old and came with the cabin, so I was not surprised.


    Running solar this winter last months bill was 1247 yen or about 10 bucks. in the past it was over 250 USD in the winter. between the mods i made to the house, and not using the mains I have for a fact saved about 600 over the last three to four months. summer will not be as drastic as no kotatsu or heat tapes, but it will still run around 60 to 100 per month.


    Tepco is following through with their plans on chargeing independantly for repairs for the mountain cabins and vacation homes So I expect a really rude letter in the near future when they go to levy some bills to pay for some repairs as I will tell them to unhook.

    18 JA solar 200 watt panels, morningstar controller(s) and a magnum 4448 inverter with all the usual junk that goes with it. and a 600 a/h 48 volt battery bank
  • EstragonEstragon Registered Users Posts: 4,482 ✭✭✭✭✭

    Hopefully they'll let you unhook on reasonable terms.

    I had a rental I expected to be vacant for some time, and asked to have water shut off. Aside from wanting to avoid fixed charges, I had heat turned down and didn't want frozen pipes. They said "no, the bylaw doesn't allow it". I read the bylaw, which does allow it. When I pointed this out, they changed their reply to "yes, we can turn it off, but we don't want to, and the bylaw doesn't give you any ability to make us".

    Oddly enough, the bylaw doesn't even impose a duty to actually supply water on the utility, just a bunch of duties on property owner in support of the utility.

    As renewables grow in some places by enough to be more than just a nuisance to utilities, I suspect there will be more moves to impose sunk costs as exit charges on grid cord-cutters.

    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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