Sorry for all theses newb questions

Options
Zakarume
Zakarume Solar Expert Posts: 143 ✭✭
in Solar Beginners Corner #1
This is bugging the hell out of me. I have switched to 24v system. better than the 12v i had

I have 4 x 100 watt panels. I have wired them in series.

My question is this. I know wiring in 2 panels in series made a large 24v panel. Amps stayed the same, but does the wattage go to 200 watts also?
1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
· Share on Twitter

Comments

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #2
    Options
    Re: Sorry for all theses newb questions

    You have it right volts add, watts add and Amps are the same in series.. you will have 2 - 200Watt arrays and 400 Watts total. NOte with parallel arrays the Amps add...
     
    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
    · Share on Twitter
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #3
    Options
    Re: Sorry for all theses newb questions

    Yes. Although if you are using a PWM controller the results are not necessarily that simple.
    For two 12V panels, the only way to use them on a 24V battery is to put them in series to get enough voltage for charging.
    But if you put two more panels in series AND you have a PWM type CC, then you will get any more power at all because the extra voltage will just be wasted.
    With an MPPT CC you will actually get twice the power going to the battery.
    SMA SB 3000, old BP panels.
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
    Options
    Re: Sorry for all theses newb questions
    inetdog wrote: »
    Yes. Although if you are using a PWM controller the results are not necessarily that simple.
    For two 12V panels, the only way to use them on a 24V battery is to put them in series to get enough voltage for charging.
    But if you put two more panels in series AND you have a PWM type CC, then you will get any more power at all because the extra voltage will just be wasted.
    With an MPPT CC you will actually get twice the power going to the battery.

    No.

    He has switch to a 24 Volt system. Same panels as before, just re-arranged the configuration of Watts into 2X the Voltage and 0.5X the current.
    · Share on Twitter
  • stmar
    stmar Solar Expert Posts: 370 ✭✭✭
    #5
    Options
    Re: Sorry for all theses newb questions

    Don't be sorry for the newbe questions, read some of my threads, lol. How else will we learn if we are doing it correct and advance our systems and knowledge? Appreciate all the help this forum gives, I have learned quite a bit and I actually had an electrical background.
    · Share on Twitter
  • Zakarume
    Zakarume Solar Expert Posts: 143 ✭✭
    #6
    Options
    Re: Sorry for all theses newb questions

    Thanks for the info. After switching to 24v on my watt meter the reading stay more stable than it did on the 12v
    1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
    · Share on Twitter
  • jvanhare
    jvanhare Registered Users Posts: 5 ✭
    #7
    Options
    Re: Sorry for all theses newb questions

    Yes, wattage increases, amps remain the same. Higher voltage and lower amps is the way to go with a DC system due to inherent losses in DC wiring. I have something similar to your system, but I use an MPPT charge controller.
    An Instapark MPPT-2010 12V/24V 20 Amp Solar Power Charge Controller, 240W/480W
    It's working well though I have my original Renogy PWM charge controller and 100 watt panel on my camper up north. I'm using 3 of the Renogy 100 watt panels in series @66 volts into the MPPT Charge Controller out to 4 deep cycle batteries and an 800 watt inverter, run my TV, surround sound and CFL bulbs in my living room. Works well so far. (Less than a year still). It's worked well when the power is out and I have a Champion 1400/1800 generator I got for $200. It is relatively quiet and very fuel efficient.
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #8
    Options
    Re: Sorry for all theses newb questions
    jvanhare wrote: »
    Yes, wattage increases, amps remain the same.

    No, it doesn't.

    Wattage remains the same.

    If the original configuration is 17.5 Vmp and 5.7 Imp (99.75 Watts - '100 Watts') * four in parallel totaling 17.5 Vmp and 22.8 Imp (400 Watts) for a 12 Volt system putting then putting the panels in a series/parallel configuration for the 24 Volt system raises the Vmp to 35 and the Imp becomes 11.4. It is still 400 Watts.
    · Share on Twitter
  • jvanhare
    jvanhare Registered Users Posts: 5 ✭
    #9
    Options
    Re: Sorry for all theses newb questions

    Yes, I guess I wasn't very clear, his system peaks at 400 watts, rereading his post I'm concerned that he is running all 4 in series into a PWM controller and wasting a lot. Wouldn't he want two series circuits connected in parallel for 24 volts out. These panels read about 22v out each open.
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #10
    Options
    Re: Sorry for all theses newb questions
    jvanhare wrote: »
    Yes, I guess I wasn't very clear, his system peaks at 400 watts, rereading his post I'm concerned that he is running all 4 in series into a PWM controller and wasting a lot. Wouldn't he want two series circuits connected in parallel for 24 volts out. These panels read about 22v out each open.

    I sure hope he hasn't got them all four in series on a PWM controller: I've explained this so many times everyone ought to understand it by now. :roll:

    Voc is pretty much irrelevant for charging purposes. It does matter on the issue of exceeding input Voltage to a controller. That also should not be an issue here.
    · Share on Twitter
  • jvanhare
    jvanhare Registered Users Posts: 5 ✭
    #11
    Options
    Re: Sorry for all theses newb questions

    Exactly, when you look at the original post, he is asking if the 2 100 watt panels in series will yield 200 watts, at 24 volts. Then he has the 4 100 watt panels listed as in series into a 30 amp PWM controller in his tag line. Not good.
    I assume he had branch connectors in his kit since it was originally a 12 volt system, so he probably has everything he needs at his house already, just not clear on wiring of series and parallel together.
    · Share on Twitter
  • Zakarume
    Zakarume Solar Expert Posts: 143 ✭✭
    #12
    Options
    Re: Sorry for all theses newb questions

    To clarify a little more. I have 2 100 watt 12v panels in series for 24v. I have the other 2 100 watt 12v panels in series also. I ran 4 lines ( 2Positive, 2 Negative) to a combiner box. Each positive goes to a circuit breaker (2 breakers being used) and the negatives to bus bar. I then ran 1 positive and 1 negative from box to Charge Controller. I did have a branch connector when it was a 12v system. I am happier switching to 24v. It is just doing series and parallel connections is confusing me a little, but i am starting to understand it better now
    1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
    · Share on Twitter

Categories