Please help, Very confused

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  • audredger
    audredger Solar Expert Posts: 272 ✭✭
    #152
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    Re: Please help, Very confused

    OK, parallel would be correct.
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #153
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    another quick question

    so I hooked up my 3 120watt solar panels to my midnite combiner which contains 6 15amp breakers and they are going to my new ts-60. Now I use to have the panels going straight to a sunforce 30amp controller and use to see readings as high as 23amps from them but now that I have them hooked to the combiner and ts-60 I am only seeing about 13.

    I called tristar and they told me that the panels have to be ran in parallel because of the ts-60 and NOT in series. Is it possible that the only reason I see so little is because they are hooked up to a 15amp breaker? Should I then only do 2 panels per breaker since 2 panels will give me 15.3 amps and since all 3 are on one breaker the breaker is stopping me with only 15amps?

    Thank you
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #154
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    Re: another quick question
    VanDeusen wrote: »
    so I hooked up my 3 120watt solar panels to my midnite combiner which contains 6 15amp breakers and they are going to my new ts-60. Now I use to have the panels going straight to a sunforce 30amp controller and use to see readings as high as 23amps from them but now that I have them hooked to the combiner and ts-60 I am only seeing about 13.

    I called tristar and they told me that the panels have to be ran in parallel because of the ts-60 and NOT in series. Is it possible that the only reason I see so little is because they are hooked up to a 15amp breaker? Should I then only do 2 panels per breaker since 2 panels will give me 15.3 amps and since all 3 are on one breaker the breaker is stopping me with only 15amps?

    I am confused--your combiner is for parallel combination of panel strings... So are not your panels already in parallel?

    Which TS-60 controller do you have? The $200 PWM or the $500 MPPT?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #155
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    Re: another quick question
    BB. wrote: »
    I am confused--your combiner is for parallel combination of panel strings... So are not your panels already in parallel?

    Which TS-60 controller do you have? The $200 PWM or the $500 MPPT?

    -Bill

    PWM is the one I have, noyt sure what the difference is other then the mppt to my understanding will do some automatic stuff. Yes, they are in parallel.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #156
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    Re: Please help, Very confused

    Then you need to check all of the wiring/connections (make sure that every panel is connected correctly--you might try shading each panel and see that the total current drops the same for each panel shaded).

    Then look at the controller and battery voltage... Charge controllers, once the battery is at the set point voltage (around 14.4 volts or so)--once that voltage has been reached, then the controller will cut back on the current flowing to the battery.

    Obviously, different days will have different maximum current levels... You can check the short circuit current for each panel (turn off the combiner breakers and check each panel wiring to the box) and verify that each panel is outputting a matched amount of current.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #157
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    Re: Please help, Very confused
    BB. wrote: »
    Then you need to check all of the wiring/connections (make sure that every panel is connected correctly--you might try shading each panel and see that the total current drops the same for each panel shaded).

    Then look at the controller and battery voltage... Charge controllers, once the battery is at the set point voltage (around 14.4 volts or so)--once that voltage has been reached, then the controller will cut back on the current flowing to the battery.

    Obviously, different days will have different maximum current levels... You can check the short circuit current for each panel (turn off the combiner breakers and check each panel wiring to the box) and verify that each panel is outputting a matched amount of current.

    -Bill

    OK Bill,

    What about the other question about keeping 2 panels per breaker? Could that be a contributing factor? IE: 15 amp breaker?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #158
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    Re: Please help, Very confused

    Two panels per breaker will do nothing for you... It might be a cheap way of sharing breakers for (two strings per breaker x 6 breakers)--but it does reduce the protection that was intended by installing the series protection devices.

    The only way the "breakers" may be causing you a problem is that if they are miss-wired, tripped, or one or more are bad for some reason...

    You should be able to, under full sun, turn off all breakers, then turn on one breaker at a time and verify that each panel is shouldering its proper load... The current between the panels should be within +/- 10% of each other.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #159
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    Re: Please help, Very confused
    VanDeusen wrote: »
    the electric company here does NOT allow for grid tie. Its either off or them. I know that I am short and working on it. I am asking questions because I dont want to spend anymore money on batteries until I figure out which is the right ones to get in the first place.


    The 2 solar panels I have show they are pushing around 10 amps in mid-day, the wind generators I will not even factor in as I cant confirm what they are providing. I did NOT enherit this system I started it a month ago and everything is NEW.

    I don't think they can do that

    "Under the federal Public Utility Regulatory Policies Act (PURPA), utilities must allow you to interconnect your PV system. They must also buy any excess electricity you generate, beyond what you use in your home or business. If your utility does not offer net metering, it will probably require you to use two meters: one to measure the flow of electricity into the building, the other to measure the flow of electricity out of the building. If net metering is not available, the utility will pay you only a wholesale rate for your excess electricity. This provides a strong incentive to use all the electricity you generate so that it offsets electricity you would otherwise have to purchase at the higher retail rate. This may be a factor in how you optimize the system size, because you may want to limit generating excess electricity. Such a “dual metering” arrangement is the norm for industrial customers who generate their own power. "

    http://en.wikipedia.org/wiki/Public_Utility_Regulatory_Policies_Act
    http://www.oe.energy.gov/purpa.htm
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #160
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    Re: Please help, Very confused
    solar_dave wrote: »
    I don't think they can do that

    "Under the federal Public Utility Regulatory Policies Act (PURPA), utilities must allow you to interconnect your PV system. They must also buy any excess electricity you generate, beyond what you use in your home or business. If your utility does not offer net metering, it will probably require you to use two meters: one to measure the flow of electricity into the building, the other to measure the flow of electricity out of the building. If net metering is not available, the utility will pay you only a wholesale rate for your excess electricity. This provides a strong incentive to use all the electricity you generate so that it offsets electricity you would otherwise have to purchase at the higher retail rate. This may be a factor in how you optimize the system size, because you may want to limit generating excess electricity. Such a “dual metering” arrangement is the norm for industrial customers who generate their own power. "

    http://en.wikipedia.org/wiki/Public_Utility_Regulatory_Policies_Act
    http://www.oe.energy.gov/purpa.htm

    they had no problem telling me they will give me the meter but they will NOT buy it. I am off-grid
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  • russ
    russ Solar Expert Posts: 593 ✭✭
    #161
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    Re: Please help, Very confused

    What you are saying is, 'To heck with the utility - İ'll show them by having very expensive power!'

    Fun to tell them to go pack sand but when your power is maybe 1 USD per kWh is it worth it?
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #162
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    Re: Please help, Very confused
    russ wrote: »
    What you are saying is, 'To heck with the utility - İ'll show them by having very expensive power!'

    Fun to tell them to go pack sand but when your power is maybe 1 USD per kWh is it worth it?

    If the man wants to spend his money making a political statement, so be it.
    But it sure isn't a practical choice. :roll:
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #163
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    Re: Please help, Very confused

    In most cases the grid is the cheapest "battery" if you have reliable power from the utility.
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #164
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    how much is plenty?

    Currently I pump 30amps of solar to the batteries. how much do you pump to your batteries (OFF GRID) How do I know when I have enough solar panels. I can run a 40 amp xantrex and within maybe a hour or two I can bring up my batteries to a full charge but it seems like when the controller (40 amp morningstar) is on and the sun is out and its pumping 30 amps to the batteries the volts still decline. I use a MSW 5000 watt inverter with that as well. I am trying to see it at least maintain and not decline.


    Not trying to get into alot of Q/A just asking how much solar amps do you as a off grid household pump on average to your batteries so that I can start to figure out on a mass scale how short I actually am.

    SO, Can people just reply with how much/many solar/amps do you have to get the job done?

    thank you all
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #165
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    Re: Please help, Very confused

    The recommended charge rate for a battery bank is 5% to 13% of its '20 hour' Amp/hr rating.
    So for every 100 Amp/hrs you want at least 5 Amps of charge current.

    This is assuming no loads are drawing from the batteries while you're trying to charge them, which is probably not the case. You get a net effect with loads:

    5 Amps charge current minus 2 Amps of load equals only 3 Amps actual charge rate.

    The same is true of "replacing the Amp/hours used"; your panels have to supply enough energy to provide the recommended charge plus run any loads while charging.

    This is why battery monitors are good: shows what's actually going in to/out of the battery instead of just what the panels are producing.

    This is also why I recommend people shoot for 10% charge rate, not the minimum 5%.
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #166
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    Re: Please help, Very confused

    so If I am pumping 30 amps to the batteries does that amount to much? Like I said if I run the 40 amp xantrax charger it WILL keep the batteries topped off no matter what I use in the house but when I use MIN. in the house and turn it off WHILE the panels are at 30amps it still declines and it seems to me for a difference of 10 amps (the difference between the 40 amp battery charger AND the panels) i would at least think that it should HOLD the volts steady but yet it declines so I am trying to figure out why since we are only talking 10 amps.

    I DO know that when I take the controller OFF the batteries and reconnect it I can see a arc so I know that they are putting out what it is telling me but yet it seems like if it really isnt. Just cant comprehend the difference between the 2 so thats why I am asking these questions.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #167
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    Re: Please help, Very confused

    Keep in mind that the Xantrex will put out 40 Amps steady whereas the panel current will fluctuate.
    But yes, 10 Amps can be a big difference. At 12 Volts (nominal) that's 120 Watts, so one incandescent 100 Watt bulb too many and you're no longer charging.

    I think you need to get an idea of how much power is going out of the batteries through the inverter while you're trying to charge. Can't remember what you've got for battery Amp/hrs, but if that's too high you will also have trouble keeping up.

    My real-world example: 320 Amp/hrs of batteries charge at about 21 Amps peak, usually average around 18 - just above the 5% minimum. Normally the total loads on the inverter are less than 100 Watts, with some cycling to 200-300 Watts. Why on Earth do I have such a big inverter, then? Because a couple of the devices chew up over 1000 Watts when used, but I only switch them on when charged and floating.
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #168
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    Re: Please help, Very confused

    the batteries are cr395's They are 6v but running at 12 (connected) so tech I have 2 12v batteries each at 395-20hr= 39.5 amps a hour which I do NOT use.. at most on the solar at one time might be

    fridge and a couple of box fans (pushing ac thru the house) and the computer. Printer is on ONLY during printing and then turned off. The stove is propane electic ignition as is the dryer and water heater (propane on demand) I had a kill a watt till it tried to start a fire so threw it out. (guess I left it plugged in too long)
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #169
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    Re: Please help, Very confused

    2 6V 395 Amp/hr batteries in series to get 395 Amp/hrs @ 12V, right?
    Times two in parallel = 790 Amp/hrs @ 12 Volts.
    That is a lot of battery. It would require at least 40 Amps of current (39.5) to be at the 5% charge rate. No wonder you're having problems. These are probably L16-style batteries too; the "tall case" design which is prone to electrolyte stratification.

    My advice: disconnect one parallel set and see how well the panels do at charging just 395 Amp/hrs. From your load description you don't need that extra 2370 Watt hours (50% of 395 * nominal 12 Volts) of capacity. Mine runs refrigerator, satellite/computer/phone set-up, water pump, digester pump, microwave, misc. lights .... See what I mean? (Mine is 24 Volts: 160 Amp/hrs (half the 320 total) @ 24V = 3840 Watt hours maximum.)
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #170
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    Re: Please help, Very confused
    Cariboocoot wrote: »
    2 6V 395 Amp/hr batteries in series to get 395 Amp/hrs @ 12V, right?
    Times two in parallel = 790 Amp/hrs @ 12 Volts.
    That is a lot of battery. It would require at least 40 Amps of current (39.5) to be at the 5% charge rate. No wonder you're having problems. These are probably L16-style batteries too; the "tall case" design which is prone to electrolyte stratification.

    My advice: disconnect one parallel set and see how well the panels do at charging just 395 Amp/hrs. From your load description you don't need that extra 2370 Watt hours (50% of 395 * nominal 12 Volts) of capacity. Mine runs refrigerator, satellite/computer/phone set-up, water pump, digester pump, microwave, misc. lights .... See what I mean? (Mine is 24 Volts: 160 Amp/hrs (half the 320 total) @ 24V = 3840 Watt hours maximum.)

    so you are suggusting just running 2 and not 4 of the batteries right? I will try that but why am I being told that I would need 16 batteries? (which of course would make 8 12 v batteries) If 4 is too much then 16 would surely be too much....
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #171
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    Re: Please help, Very confused

    Why would you need 16 batteries? It all depends on how many Amp/hrs you require to fulfill your use at what Depth Of Discharge you're willing to risk:

    8 * 395 = 3160 Amp/hrs @ 25% DOD = 790 "usable" Amp/hrs (as opposed to 2 * 395 = 790 total Amp/hrs which would supply 395 @ 50% DOD but only 197.5 @ 25% DOD).

    At any rate, your 360 Watts of panels are only good for charging approximately 400 Amp/hrs:
    360 @ 80% efficiency (typical) = 288 / 14.2 Volts (charge) = 20 Amps which is 5% of 400.

    None of that includes additional losses particular to your system, as in solar exposure, relative temperatures, wire lengths, et cetera. In terms of daily 'harvest' those panels would probably provide just over 1 kW hour per day. If your usage exceeds this you'll have a problem no matter how big your battery bank.
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #172
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    Re: Please help, Very confused

    right, I am still working on getting 12 more 120 watt panels. Can you PLEASE tell me then if I get 12 more how many batteries do you recommend with 16-120's? keeping in mind that I would probably use the cr395's (battery)
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #173
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    Re: Please help, Very confused

    12 more 120 Watt panels would be 1440 Watts @ 80% = 1152 Watts / 14.2 V = 81 Amps.
    That's enough panel for 800 Amp/hrs of battery above what you've got based on nominal calculations (no real loss configuration). But this is more than any one charge controller can handle (even the FM 80). It is also above the usual amount for a 12 Volt system. Together with your existing 360 Watts you'd have 1800 Watts of panels. You're into pretty high current here: over 100 Amps DC charging. About 5.8kW hours harvest per day. This is when you start thinking about upping your system Voltage to reduce current and improve efficiency. That many panels calls out for an MPPT controller with higher Voltage array and down-converting efficiency.
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  • System2
    System2 Posts: 6,290 admin
    #174
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    Re: Please help, Very confused

    Thank you for the information, I learned a lot of new things
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  • James
    James Solar Expert Posts: 250 ✭✭
    #175
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    Re: Please help, Very confused

    Could the 8-15 watt smaller panels be too large a difference and be reducing the available power from the larger panels?

    I seem to remember something about keeping panel sizes close in output especially on a 12 volt system. Am I incorrect about panel sizing?
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  • nsaspook
    nsaspook Solar Expert Posts: 396 ✭✭✭
    #176
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    Re: Please help, Very confused
    James wrote: »
    Could the 8-15 watt smaller panels be too large a difference and be reducing the available power from the larger panels?

    I seem to remember something about keeping panel sizes close in output especially on a 12 volt system. Am I incorrect about panel sizing?

    My smaller 15W panels work just fine in parallel with higher wattage panels on a PWM controller. They have a much different power curve so I don't see much power from them until the load on the primary 80W panels drops the PV voltage to below 15.0 vdc.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #177
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    Re: Please help, Very confused
    James wrote: »
    Could the 8-15 watt smaller panels be too large a difference and be reducing the available power from the larger panels?

    I seem to remember something about keeping panel sizes close in output especially on a 12 volt system. Am I incorrect about panel sizing?

    Yes you're technically right. Lots of debate about how much difference is too much and what kind of losses are acceptable. But it's more a matter of not reaching full potential rather than one panel causing a drop in output. In other words the 35 Watt won't bring a 100 Watt down to less than 100 Watt but nor will you get 135 Watts in combination.

    Oh dear; I'm not explaining it well. :blush:
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #178
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    Re: Please help, Very confused

    If you put panels in parallel--you will need series protection fuses for each string... For smaller panels, you will need smaller series protection fuses.

    Adding wattage in parallel (or series)--is not really an issue... It is placing panels with different Vmp in parallel (or Imp in series) that is the issue.

    If Vmp (or Imp) different by more than (roughly) 10%--then you may have relatively large power losses/controller functionality issues.

    And it also matters if the controllers are MPPT or PWM... MPPT controllers may get confused/stuck on a lower MPPT "Peak" if the Vmp of the array has multiple voltages installed (17 volt vs 16 volt is not the issue--but 16 volt vs 24 volt would be).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #179
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    Re: Please help, Very confused

    I use a combiner so the 8-15 watt panels are ties into each other and then going to the combiner which has a breaker of 15 amps. Since the 15 watt panels were my first mistake, I decided to connect them and use them after I started to grow the system as to NOT waste any $$ from them. They are putting out. They are setup so that in the morning before the main panels get sun, they are producing around 3-4 amps to the batteries until the sun is in the 11:00am position at which case then I see 30 amps of power so the 15 watt panels just give me a lil ole early start.
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #180
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    Re: Please help, Very confused

    Also I might add, in order to go up on volts wouldnt I have to redo the whole system since its all 12v?
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  • VanDeusen
    VanDeusen Solar Expert Posts: 129 ✭✭✭✭✭
    #181
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    auto start generator

    can you point me in the right direction....


    I am looking for something like a generac but not a high dollar one.


    I need a generator that will monitor my system and automatically start when lets say my battery system falls to 11.9 and shut off when its fully charged, then monitor the batteries until it needs to start again BUT it of course also has to be compatible with the solar 12v system that I have. Prefer it to run on propane as well.

    Do they make such a thing? I think anywhere between a 400 and 2500 watt generator will do. ALSO, it would be easier if it just hooked right up to the batteries and does its own thing where I just need to monitor the oil level as it would be hooked up to a propane system.
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