I have two separate trackers with different solar panels. I now need to "combine" both trackers into one system, with a common charge controller, battery bank, and inverter. Tracker #1 has 8 Arco 16-2000 panels with specs of 33 watts, open ckt 21.6v, rated at 16v. System #2 has 4 siemens SR-90s with specs of 90 watts, open ckt 20v, and rated at 17v. Since they are of very similar voltages, can I combine them without any significant problems? Any feedback would be greatly appreciated.
Can I Combine These Trackers?
Collapse
X
-
-
I would suggest a separate MPPT controller for each array.
You did not say what voltage your arrays are wired for, or your battery voltage.
Parallel panels, need fuses installed to be safe. Series panels don't need fuses.
2 fairly equal arrays, can be paralleled with out a fuse, but add a 3rd, and you need fuses on all.Powerfab top of pole PV mount (2) | 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 -
I would suggest a separate MPPT controller for each array.
You did not say what voltage your arrays are wired for, or your battery voltage.
Parallel panels, need fuses installed to be safe. Series panels don't need fuses.
2 fairly equal arrays, can be paralleled with out a fuse, but add a 3rd, and you need fuses on all.Comment
-
OK, now that I know how (I think everything is in parallel) your arrays are wired, and system voltage,
I have 2 different paths to suggest.
Leave it all in parallel, 16.5V and use PWM controllers.
Tracker #1 has 8 Arco 16-2000 panels with specs of 33 watts, open ckt 21.6v, rated at 16v.
System #2 has 4 siemens SR-90s with specs of 90 watts, open ckt 20v, and rated at 17v
Poor choice, tracker 1 will fall below battery charging voltage on anything other than cool or windy days, as PV panels heat up, their output voltage drops. 16V is barely enough to generate charge on low batteries, and will do little for nearly full batteries.
When you say "tracker" you have a system that follows the sun from sunrise to sunset?
This "All Parallel" system will also need to have 12 fuses (one at each panel) and several combiner boxes to be safe.
Also, each array will need large gauge wire (about #10 & #8 awg, respectively) going to a large, 40A PWM charge controller.
--- OR ---
the other way is to split each array to a series/parallel wiring, and 2 different MPPT controllers.
Tracker #1 has 8 Arco 16-2000 panels with specs of 33 watts, open ckt 21.6v, rated at 16v.
4 panels in series = 64V, parallel 2 strings of 4 = 4A for the wire run to the controller, 14ga wire fine
System #2 has 4 siemens SR-90s with specs of 90 watts, open ckt 20v, and rated at 17v
4 panels in series = 68V, 1 string of 4 = 5A for the wire run to the controller, 12ga wire fine
Both are well below the 150VDC limit for the professional MPPT controllers. Depending on the wire distance, you may save enough on the wiring to pay for the 2 MPPT controllers. Rogue and Midnight make some rugged entry level MPPT controllers. The Rogue, you may have to check it's input DCv limit.Powerfab top of pole PV mount (2) | 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-ListerComment
-
OK, now that I know how (I think everything is in parallel) your arrays are wired, and system voltage,
I have 2 different paths to suggest.
Leave it all in parallel, 16.5V and use PWM controllers.
264w, 16A
360w 21A
Poor choice, tracker 1 will fall below battery charging voltage on anything other than cool or windy days, as PV panels heat up, their output voltage drops. 16V is barely enough to generate charge on low batteries, and will do little for nearly full batteries.
When you say "tracker" you have a system that follows the sun from sunrise to sunset?
This "All Parallel" system will also need to have 12 fuses (one at each panel) and several combiner boxes to be safe.
Also, each array will need large gauge wire (about #10 & #8 awg, respectively) going to a large, 40A PWM charge controller.
--- OR ---
the other way is to split each array to a series/parallel wiring, and 2 different MPPT controllers.
264w
4 panels in series = 64V, parallel 2 strings of 4 = 4A for the wire run to the controller, 14ga wire fine
360w
4 panels in series = 68V, 1 string of 4 = 5A for the wire run to the controller, 12ga wire fine
Both are well below the 150VDC limit for the professional MPPT controllers. Depending on the wire distance, you may save enough on the wiring to pay for the 2 MPPT controllers. Rogue and Midnight make some rugged entry level MPPT controllers. The Rogue, you may have to check it's input DCv limit.Comment
-
Mike, my two trackers are manual trackers that move in both vertical and horizontal directions that look like the old Zomeworks trackers-and will be readjusted seasonally......My panels are already wired with solar USE cable AWG 10, so I'm staying with parallel wiring, but have no fuses installed between panels, so I'll be doing that, and installing a MPPT controller for each array.thanks..........Incidentally, my Arco 16-2000s were originally designed to NOT use a charge controller because their rated 16 volts can't overcharge a 12 volt battery, and I was going to do exactly that, like many did back in the good old days of Home Power magazine editorials. However, I was warned to use a charge controller to keep the battery topped off properly, or "equalized" into staying full. Anyway, what is the bottom line if I insist on combining both trackers at 12 volts into my already purchased Xantrex C-60, a charge controller that can handle up to 60 amps continuous? Joe
Since they significantly different current values, mixing the two panel types into one series string is not an option.SunnyBoy 3000 US, 18 BP Solar 175B panels.Comment
-
The open circuit voltages of 20V and 21.6V are too low to be totally reliable for charging a nominal 12V battery bank, but they should work. And since the two voltages are within 5% of each other you could also parallel them into an MPPT charge controller IF the CC specs say that it will accept that low an input voltage. But better to put each type of panel into a separate series/parallel circuit to get a higher voltage.
Since they significantly different current values, mixing the two panel types into one series string is not an option.Comment
-
inetdog, thanks, that's what I wanted to hear- so, it sounds like I can combine these two trackers at 12 volts. Now, do I need to put fuses in between each panel of each tracker? If the Arcos are 33w/12v @2.7 amps, do I use a 2.7 amp fuse? (or thereabouts?) And if the Siemens are 90w/12v @7.5 amps, do I use a 7.5 amp fuse? (or thereabouts) ThanksComment
-
With your low voltage array, MPPT controllers are pointless.
My suggestion is, instead of adding all those fuse holders and fuses, rewire into series/parallel as I described, and then you can reap the benefits of the MPPT controllers. It's conceivable that both arrays could go onto one MPPT controller, and work, but as a backup, prepare to add a 2nd controller.
Putting both arrays in PARALLEL with each other, will drag the 17v array down to 16v to match the other, lower voltage. There is a great risk to undercharging your batteries with this method in the summer, when the heat causes the array voltage to droop. Hoping for the 21V of unloaded panels to charge the batteries, is pointless.
As to the fuses, nobody makes a 2.7 or 7.5a that is affordable. If you can't find 4A fuses, use a 5A, and then for the 7.5, use a 10A
good luckPowerfab top of pole PV mount (2) | 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-ListerComment
-
With your low voltage array, MPPT controllers are pointless.
My suggestion is, instead of adding all those fuse holders and fuses, rewire into series/parallel as I described, and then you can reap the benefits of the MPPT controllers. It's conceivable that both arrays could go onto one MPPT controller, and work, but as a backup, prepare to add a 2nd controller.
Putting both arrays in PARALLEL with each other, will drag the 17v array down to 16v to match the other, lower voltage. There is a great risk to undercharging your batteries with this method in the summer, when the heat causes the array voltage to droop. Hoping for the 21V of unloaded panels to charge the batteries, is pointless.
As to the fuses, nobody makes a 2.7 or 7.5a that is affordable. If you can't find 4A fuses, use a 5A, and then for the 7.5, use a 10A
good luckComment
-
Comment
-
Russ, yeah, it is just my opinion, but, you know reality is "relative" thing. It's kind of like "time". Thanks to people like Einstein, science has learned that there isn't one "reality". I mean, if a energy-conscious individual wants to get into solar, the "current reality" is going to suck you down a hole from which you'll spend a ton of money, hiring a solar engineer who really knows what he's doing @ $300 an hour, and ultimately never recoup the cash you've "saved" off utility bills. You may think that all this is "just my opinion", but the evidence shows otherwise. Since I'm a scientist, I don't mind hearing what solar engineers have to tell me about how out of control the solar industry has gotten. It's no surprise that I live in the windiest and sunniest part of California, and there's ONE wind generator (mine), and a handful of solar panels on the roofs of the rich and famous. Now, could solar exorbitant costs have anything to do with it?Comment
-
Rooftop solar - with the various incentive programs and subsidies it is affordable and practical in places with high power costs.
Nothing is out of control - just the greens pushing a technology that isn't ready for prime time yet.[SIGPIC][/SIGPIC]Comment
-
Russ, yeah, it is just my opinion, but, you know reality is "relative" thing. It's kind of like "time". Thanks to people like Einstein, science has learned that there isn't one "reality". I mean, if a energy-conscious individual wants to get into solar, the "current reality" is going to suck you down a hole from which you'll spend a ton of money, hiring a solar engineer who really knows what he's doing @ $300 an hour, and ultimately never recoup the cash you've "saved" off utility bills. You may think that all this is "just my opinion", but the evidence shows otherwise. Since I'm a scientist, I don't mind hearing what solar engineers have to tell me about how out of control the solar industry has gotten. It's no surprise that I live in the windiest and sunniest part of California, and there's ONE wind generator (mine), and a handful of solar panels on the roofs of the rich and famous. Now, could solar exorbitant costs have anything to do with it?Comment
-
Residential wind is generally a loser - more of a pain than useful plus a tall tower is required..
Rooftop solar - with the various incentive programs and subsidies it is affordable and practical in places with high power costs.
Nothing is out of control - just the greens pushing a technology that isn't ready for prime time yet.Comment
Comment