Baja Beach House Solar System...your opinions?

System
System Posts: 2,511 admin
Hi,

This is a great forum. I am putting together a solar system for my new 2 bed/2bath 1600sf beachfront casa in Baja. It is off-grid with possibility of being grid tied in next year or two. It gets a ton of sun. It is mainly a vacation house for my family but we will rent it as well. I spent 2 1/2 months there from Feb to April (drove back up due to swine flu scare) and learned to live on very little power.

The issue is that renters will not conserve so for those several weeks out of the year I rent it I will need some type of generator that will keep those renters happy. I do not want to spend the big bucks on sizing the solar system for those times renters come but rather spend it on a propane generator.

Oh and we need to order all this and have it by July 1st to drive it down in our Ford 150 v8 long bed.

So here is my proposed configuration and all the items on a quote I rec'd:

8 Kyocera KD135 panels
1 Xantrex XW6048 Inverter
1 Xantrex XW Power Distribution Panel
1 Xantrex XW Remote System Control Panel
1 Xantrex XW60 SCC MPPT60-15, 60 amp charge controller

now the following was in the quote but I don't really know what they are for:

1 XW 60 amp DCBreaker 160 VDC surface mount
1 XW 80 amp DCBreaker 125 VDC surface mount
1 MidNite MNPV-6, 6 position combiner box
2 CBI OBPV-15 DC Breaker 150 VDC din-rail mounted
4 MC4 10 AWG - 30' cable extension
1 4/0 - 120" UL Cable, Battery/Inverter (Black)
1 4/0 - 120" UL Cable, Battery/Inverter (red)
1 Xantrex TM500 AH/Volt Meter with Shunt
1 Xantrex TM500 TM-48 adapter for 48VDC systems
4 IronRidge Rail, XRS 1 at 120" (10 ft) Set, Anodized
4 IronRidge Kit, XRS Feet-Tall (4) set
3 IronRidge kit, Mid Clamp 2.0" (4) Set,Bronze
2 IronRidge Kit, End Clamp 1.50" (4) Set, Bronze
4 Lay-in Ground Lug with Stainless Screw (1)
16 IronRidge XRS WEEB Grounding Clip
6 UniRac 30" Low Profile Tilt Leg Kit (1 leg/kit)

My question is if I'm spending 1k+ on the distribution panel are all these other cables etc needed?

Also, what is a Volt Meter with Shunt? and is it necessary? that is the most expensive item of the misc items above i do not understand what they are.

I currently have installed down there 4 Trojan L16 6v 390ah batteries. I will be bringing 4 more down there for a total of 8. I realize i am undersized on the batteries but they are heavy and I am running a 48v system so it is either 8 or 16 running 8 in parallel right? or could I bring 8 for a total of 12 and still run a 48v system?

I want to also bring down a generator that will automatically turn on when it senses a surge or low battery power. Any recommendations on a generator that uses propane, is liquid cooled, runs 1800 rpm and will run a 2 bed, 2 bath house with one family of 4 using blow dryers etc?

So what I'm asking in general is I know I undersized the solar system for renters, but am willing to put the dinero ($) into a decent generator and am looking for one I can buy here and drive down there.

A local will be installing the system. I am purchasing it up here as the cost of this stuff is basically 2x down there. Wondering if I need to bring down all the stuff to perch the panels on the roof or just buy it from a hardware store down there.

While we're at it I also need to buy an energy efficient front loader washing machine...any recommendations? I couldn't find any in Cabo at Costco or Home Depot. I also need a dryer that runs on propane. Will try to buy and fit as much as possible into our truck for the drive down.

Any help will be appreciated.

BajaSur

Comments

  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Baja Beach House Solar System...your opinions?

    The shunt is a gizmo that you put in the battery negative line.

    It's heavy duty like the battery cable, has a calibrated resistor in the center and has two "taps" that allow you to attach meter leads on either side of the resistor.

    This way, you can run thin wire from the shunt to the meter, and the meter doesn't have to be able to handle a bunch of amperes of current passing through it.

    If I were spending what you are spending, I would definitely include a battery meter - which will need a shunt.



    You might also want to search this forum for a user named AlanRT. There are several long threads discussing what he's been going through troubleshooting a customer's system down in Baja.

    Notably, his customer has already had several generators fail.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Baja Beach House Solar System...your opinions?

    In a heart beat :http://www.usa-generator.com/honda/

    PLEASE NOTE THAT I ERRED IN MY MATH,,, AND FIGURED THE NUMBER OF BATTERIES IN A 48 VOLT STRING WRONG!!! AS A RESULT ALL THE NUMBERS ARE WRONG,,, EVEN THOUGH THE IDEA IS RIGHT,,, I THINK!

    On the hand a Onan emerald series Rv generator is pretty reliable,, and can be had quite cheap. Both Honda and Onan can be had to run on Propane.

    A couple of quick observations on your system. First,, I would be very careful adding new batteries to an existing string. The net effect of doing so significantly shortens the live of the newest batteries in the string. Not really a problem if the batteries are ~1 year old or so,,, but if they are older,, you are throwing a good number of years away potentially on your extra batteries.

    Second, I would make sure that your charge/generator parameters are set strongly in favour of using the genny,, to keep the batteries from being over discharged. With tenants who don't understand the system,, setting the genny to start when the batteries reach say 75% soc might be way better in the long run than setting it to start at 50%.

    You can run any combination of batteries in a string that add up to 48vdc,, 4 paralleled 6 vdc=48vdc . 3 sets of 4= 12 batteries=48 vdc. What you want is the net battery size to be right for the loads on a daily,, or multiday basis, AND you want them to be able to be charge at a rate of ~5-13% of TOTAL AH capacity by your solar array.

    So for example 4 batteries strung to make 48vcd would have a ah capacity of 390ah at 48 vdc. Three strings would then make ~1170 ah @ 48 vdc,, requiring a charge rate of between ~ 58 and ~150 amps @ 48 vdc (nominal) Your given panel array would yield somewhere in the neighbourhood of only ~20 amps,,, not really enough. Unless you are prepared to use the generator extensively, you run the risk of chronically undercharging your battery bank,,, and hastening it's demise. Of course you can supplement the batteries with the genny,, but you have to factor in the run time and the fuel cost,,, as well as if people don't like to hear it, particularly at night.

    Finally,, in the Baja,, what do you need a dryer for.. Won't things air dry in a matter of a couple of hours?


    Good luck, welcome to the forum,,, and you are doing the right thing by reading and learning BEFORE you "ready, fire, aim."

    Tony
  • System2
    System2 Posts: 6,290 admin
    Re: Baja Beach House Solar System...your opinions?

    In a heart beat :http://www.usa-generator.com/honda/

    On the hand a Onan emerald series Rv generator is pretty reliable,, and can be had quite cheap. Both Honda and Onan can be had to run on Propane.

    Thanks for the info on gennys. Will check them out.


    A couple of quick observations on your system. First,, I would be very careful adding new batteries to an existing string. The net effect of doing so significantly shortens the live of the newest batteries in the string. Not really a problem if the batteries are ~1 year old or so,,, but if they are older,, you are throwing a good number of years away potentially on your extra batteries.

    Current batteries installed are 3 months old.


    Second, I would make sure that your charge/generator parameters are set strongly in favour of using the genny,, to keep the batteries from being over discharged. With tenants who don't understand the system,, setting the genny to start when the batteries reach say 75% soc might be way better in the long run than setting it to start at 50%.

    Good info...will do.



    You can run any combination of batteries in a string that add up to 48vdc,, 4 paralleled 6 vdc=48vdc . 3 sets of 4= 12 batteries=48 vdc. What you want is the net battery size to be right for the loads on a daily,, or multiday basis, AND you want them to be able to be charge at a rate of ~5-13% of TOTAL AH capacity by your solar array.

    What does vdc mean? I thought they had to be in lines of 8 if they are 6v so 6x8=48. How do you get to 3 sets of 4 = 48v? I know I'm missing something on this one...


    So for example 4 batteries strung to make 48vcd would have a ah capacity of 390ah at 48 vdc. Three strings would then make ~1170 ah @ 48 vdc,, requiring a charge rate of between ~ 58 and ~150 amps @ 48 vdc (nominal) Your given panel array would yield somewhere in the neighbourhood of only ~20 amps,,, not really enough. Unless you are prepared to use the generator extensively, you run the risk of chronically undercharging your battery bank,,, and hastening it's demise. Of course you can supplement the batteries with the genny,, but you have to factor in the run time and the fuel cost,,, as well as if people don't like to hear it, particularly at night.

    OK I'm a bit confused by what you say in the above paragraph. Are you saying that if I have 12 of these batteries my current panel wattage isn't sufficient to charge them enough? in that case getting more panels would solve this problem or putting 8 batteries instead of 12 might be better so as not to have to buy more panels?


    Finally,, in the Baja,, what do you need a dryer for.. Won't things air dry in a matter of a couple of hours?

    Well yes but to run a dryer on propane doesn't cost much. Plus it makes the towels not stand straight up. So you can hang everything outside but to make it soft you can throw them in the dryer. Other reason is if we have renters back to back we may need to dry sheets, towels quicker. Or I guess I could always buy extra sheets and towels.


    Good luck, welcome to the forum,,, and you are doing the right thing by reading and learning BEFORE you "ready, fire, aim."

    Thanks Tony...that is my objective. That is why I'm kind of undersizing right now as I figure I will learn a lot over the next couple years what our true needs are. I stayed there for 2 1/2 months using 2 10 year old 80w panels with 4 of these batteries. Of course sometimes I had to turn our LOUD construction grade 5500w generator on for showers (for water pump) or when battery power was too low.

    Tony
  • TnAndy
    TnAndy Solar Expert Posts: 249 ✭✭
    Re: Baja Beach House Solar System...your opinions?
    icarus wrote: »
    I

    You can run any combination of batteries in a string that add up to 48vdc,, 4 paralleled 6 vdc=48vdc . 3 sets of 4= 12 batteries=48 vdc. What you want is the net battery size to be right for the loads on a daily,, or multiday basis, AND you want them to be able to be charge at a rate of ~5-13% of TOTAL AH capacity by your solar array.

    So for example 4 batteries strung to make 48vcd would have a ah capacity of 390ah at 48 vdc. Three strings would then make ~1170 ah @ 48 vdc,, requiring a charge rate of between ~ 58 and ~150 amps @ 48 vdc (nominal)



    Tony


    I'm confused too by that battery math. I think, Tony, you are mixing 12v in the batch there....

    It would take 8 -- 6v L16's wired in series to make a 48v string @ 390amp/hrs.

    Additional strings would have to be more groups of 8, wired in parallel to the first one, each on adding another 390amp/hrs of capacity.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Baja Beach House Solar System...your opinions?

    TNANDY,

    How right your are,,,math was never my long suit.

    6 volt batteries,, need 6 per string! Dumb me. If each 6 volt in the string is 390 ah @ 6vdc,, a string of 6, six volt batteries in series will be 48vdc,,390 ah or ~18,720 watt hours (1 six volt at 390 ah =~2340 watt hours. (If my math is right this time)

    To Baja Sur,

    12vdc= 12 Volts Direct Current.

    Since Baja Sur has responded to my original response I won't go back and edit,,, as that would only make things more confused..

    Sorry for the current confusion.

    T
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Baja Beach House Solar System...your opinions?

    While you are wireing up, take a look here
    http://www.smartgauge.co.uk/batt_con.html
    about connecting on the "diagonal".
    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 ,

  • TnAndy
    TnAndy Solar Expert Posts: 249 ✭✭
    Re: Baja Beach House Solar System...your opinions?
    icarus wrote: »
    TNANDY,

    How right your are,,,math was never my long suit.

    6 volt batteries,, need 6 per string! Dumb me. If each 6 volt in the string is 390 ah @ 6vdc,, a string of 6, six volt batteries in series will be 48vdc,,390 ah or ~18,720 watt hours (1 six volt at 390 ah =~2340 watt hours. (If my math is right this time)


    T


    ahahhaaaaaaa......OK man....this is getting downright funny now....

    6x6v=36v

    Takes 8

    ( and I'm buying you a cheapy calculator for Xmas..... ;) )
  • System2
    System2 Posts: 6,290 admin
    Re: Baja Beach House Solar System...your opinions?

    Tony
    OK well at least I understand math if not this solar stuff. Thanks so much for your help. To confirm 6vx8=48v. Builder just said to change inverter to 24v to have more flexibility with batteries. I told him I kinda like the XW6048 inverter and wanted to stick with that...this is all so confusing...

    So I just found out the existing 4 batteries I have in baja are L-16 AEC. What the heck are those? I hope I can find ones that match.

    BajaSur
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Baja Beach House Solar System...your opinions?

    Andy,

    There you go again,,, confusing me with facts!!

    Boy do I feel stupid!

    If we weren't so far into the thread I would have everyone delete their own contribution to save me some public shame!

    BB

    (think I can get away with that?)
  • TnAndy
    TnAndy Solar Expert Posts: 249 ✭✭
    Re: Baja Beach House Solar System...your opinions?

    Just tell me where to send that calculator, and we'll call it even....ahahaaaaaa.....I have those days too......
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Baja Beach House Solar System...your opinions?

    My problem is that it is not just one of those days,,, I think I am fundamentally dislexic, not real smart either!

    Tony
  • TnAndy
    TnAndy Solar Expert Posts: 249 ✭✭
    Re: Baja Beach House Solar System...your opinions?

    Nah....ain't buying that.....seen enough of your posts to know you're a pretty sharp cookie.....I may not always agree with you, but you have my respect.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Baja Beach House Solar System...your opinions?

    Send the calculator to PO box 218,,, no wait,, that was 812 no, it is 182 ,,,oh never mind!

    Tony
  • hillbilly
    hillbilly Solar Expert Posts: 334 ✭✭
    Re: Baja Beach House Solar System...your opinions?

    Thanks Tony,
    I'm glad to see that I'm not the only one prone to some moments of sdlexsia. 'Sides I always have felt that math was overated by a good percentage...
    :)