Tracking input vs output?

Steven Lake
Steven Lake Solar Expert Posts: 402 ✭✭
Okay, I've got a crazy question for you guys.  Is there a simple way to track input (ie, amp hours generated) vs output (ie, amp hours or watt hours used)?  I'm looking to evaluate some of my systems and see how much is being generated vs how much is being used.  Right now it's more just a morbid curiosity than a necessity.  I guess the curiosity bug got the better of me and I wanted to see if there was an easy way to do both.  I know you can track watt hours used with a simple usage meter, but I wasn't sure about tracking amp hours used or generated.  Anyone know of something, or is that one of those "nobody does it so no there's nothing that can do that" kinda things?

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    since I have Midnight, Xantrex and Morningstar gear, I log manually, data every day, showing harvest, loads and time in Abs & Float and lowest voltage.   I keep it all in a spreadsheet:


    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 ,

  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,713 ✭✭✭✭✭✭
    The Outback and Schneider systems will give you more data than a human should be looking at. All very easy if you have the equipment. It will e-mail,text,cloud, and with google voice call you.  I would much rather be outside than play with this stuff. I have to for my clients but really all that is required is looking out the window, did you complete charge yesterday? Was the KWH produced about normal? And when is the next scheduled EQ and maintenance.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail [email protected]

  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    Sorry for being away for so long.  I got sidetracked with life.  Go figure.  So, is this equipment that's part of your charging gear, or is it something separate from the charge controller?  I'm looking for something easily mobile that I can tag on as needed and test various units around the farm as required.  I don't need to monitor one thing all the time per say.  I'd prefer being able to go out to, for example, a unit that's under performing or regularly running out of power, and slap this on it to see what it's doing or not doing.  For me it'd be more of a troubleshooting tool than one of those "Hey, look how much I made!"  I've got a complete monitoring setup on my main rigs (comes with the charge controllers) but nothing for the smaller stuff, especially the remote monitors.  For me those monitors, small as they are, have been a thorn in my side.  If I had my way I'd get rid of them.  But since we can't due to their necessity, I'm looking for solutions to make maintenance and repairs easier by helping me with troubleshooting. :)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,412 admin
    Some sort of standalone data logger (Battery Voltage can tell you quite a bit):

    http://www.dataq.com/data-logger/voltage/
    http://www.mccdaq.com/usb-data-acquisition/USB-503.aspx

    -Bill

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    Okay, yeah, now THAT's what I'm talking about!  :D  Thanks as always, BB. :)  That USB 503 should be exactly what the doctor ordered.  Just tag and forget more or less and then come back in a couple days to see how the performance is. :)  Perfect.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,412 admin
    Of course, you can measure mVolts across a shunt (precision/high power resistor)--And that would be converted to Amp*Hours in/out (+/- polarity on voltage across shunt).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    edited October 2015 #8
    • I'm with Dave. I eyeball the panel on the CC in late afternoon.  If our system reaches float each day I'm quite content. I don't need to know more than that, but I do admit I look at the kWh production too.  If the CC doesn't reach float and it's because it was cloudy or we had company and used a lot more power for some reason I'm aware of, I'm okay with that too. If bad weather persists a few days, I run the Honda a while. I'm okay with that too as the Honda can use a little run every so often.  I have a log for battery cell sp. gr. That is more important data than all the other stuff, IMO. 
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,713 ✭✭✭✭✭✭
    That SG log is really helpful when things turn sour. A client with 8 new Trojan L16's had 4 batteries with a good 4 week history all of a sudden not go above 1.200.  Yea, 12 cells all bad at once. He was lucky to have a good distributer who loaned him 4 while Trojan does an FA. 
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail [email protected]

  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    Wow, Dave, that's crazy.  Oddly enough I've had a number of bum cells lately too.  A lot more than I should have.  Thankfully though they've all been on the small remote units and not the bigger home or barn units.  Most are the 9ah or smaller batteries, and the vast majority of those, oddly enough, come from UPG who I've had great luck with prior to this.  But this year, and part of last it's been the UPG graveyard around here it seems.  Lots of RMA's.  That's what spawned one of my other posts about dry cells trying to find a way to store batteries for hot swaps without worrying about the battery degrading in storage.  Of course, at the rate in which those batteries have been cratering, it hasn't been an issue yet.  lol. 

    And if this keeps going I'm just gonna find me another brand for my small capacity batteries for my remote stations.  It's not the end of the world when they die, as it just means a little extra ATV time to go check on the herds.  But even so it's still a pain in the butt because when one dies makes my life more difficult as a number of them are kinda hard to get to way out in the back 40.  Thankfully so far the full extent of my problems with my solar powered remote monitors has just been primarily the batteries as the rest of the units have worked fine.  Even so it's annoying.  lol.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,412 admin
    Out of curiosity--What are the monitors monitoring?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    Well, on the big rigs have monitors for everything from usage to production.  So basically cradle to grave observation.  The small ones presently don't have any monitors.  That's why I wanted the portable units so if one of the remote monitors goes down and I discover it's because it ran out of power, I just toss one of these onto that unit and find out where the kink in things is.  Or at least that's what I'm hoping this will do.  Up to this point I've had to kinda guess my way through a problem.  The little units you suggested would make that process a lot easier.  At this point most all of my problems have been battery failures.  However, I'm suspicious if it's really a whole pack of bad batteries, or if I've got other issues that I need to address.  I'm hoping these little monitors will tell me which it is.  I'm not sure if it's insufficient production, too much draw on the battery, not enough charge entering the batteries, or if it's something else.  Since I don't have time to babysit the units, having the ability to go out there and snap one of these on and come back in a few days to see what the deal is will prove invaluable to me.  I wish I didn't have any problems with my solar rigs.  But as good old Murphy's law states, you can't have everything be perfect all the time. :P
  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    Okay, just wanted to give everyone a quick update.  So far I've got three of the four "problem children" solved using the monitors that you guys recommended.  Two were insufficiently sized panels.  Apparently for some reason two of the field and cattle monitor stations weren't getting enough juice from the panels to top off the batteries, or even really keep them in a decently usable state, thus the tanking batteries that were dying prematurely.  New panels didn't seem to solve the issue (most likely just the location) so I went a size larger and all is happy.  The third was a case of a bad charge controller, and the fourth I'm still not sure on.  All checks out power generation wise, but it's still killing batteries.  So if I can't figure out what's wrong by spring I'll probably just replace the entire setup and start from scratch across the board.

    One neat little addition I have to my shop that you guys might get a bit jealous of is a set of grow lights.  Why would that be important to solar power?  Because they generate the same conditions as direct sunlight, so I've been using them to test panels. :)  We have enough panels on the farm now that I've begun to build my own little solar workshop to keep everything humming right along. ;)
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    ...
    One neat little addition I have to my shop that you guys might get a bit jealous of is a set of grow lights.  Why would that be important to solar power?  Because they generate the same conditions as direct sunlight, so I've been using them to test panels. :)  We have enough panels on the farm now that I've begun to build my own little solar workshop to keep everything humming right along. ;)
    Cool. One thing to keep in mind when testing panels with discrete (point) light sources is that the output of the panel is limited by the least illuminated part of the panel and it can be hard to get a uniform light distribution with a homebrew setup. For comparative rather than absolute tests it should work just fine.
    SMA SB 3000, old BP panels.
  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    Yeah, that's all I'm doing with them.  I'm using an old set of 1000w Virtual Sun grow lights with the heavy duty ballasts and the broad hoods.  Suckers will give you a suntan if you're not careful.  lol.  Plus the danged ballasts will about give you a hernia lifting them.  haha.  I have them setup so they try and minimize those dark spots to ensure I get the best results when testing.  The only thing I don't like about them is when I switch them on my power bill nearly doubles.  hahaha.  Otherwise they've been really useful for testing purposes.  Ironically I got them for a song at a police seizure auction for like $20 for the pair with all the extras (fan, ballast, etc).  Evidently nobody knew what they were. :P  If I'd known that I probably would have bid $5 for the pair instead of $20.  lol.