Hi all,
I have two Solar World SW 285 mono panels, a 12 volt battery system (2 Trojan LG 16 REs), and a Outback Flexmax 60 MPPT controller. My cable run is 75 feet using 1/0 AL. Shade is generally not an issue although with snowfall I guess it could happen or an oak leaf or something... Temps can be around 100 degrees a few times each summer. Specs on the panels, 285 Watts, 31.3 V, 9.2 A, 39.7 Voc, 9.84 Isc.
Did I leave anything out?
So parallel or serial? And could someone explain to me what "string" means! That term just doesn't register for some reason...
thank you!
With those panel specs and a 12 V battery your system will be most efficient in parallel.. that is 2P
a string is one or more panels connected together, you will have 2 strings of 1 panel, usually people use 'string' when they have 2 or more in series...
"2P"?
If I go parallel, is it true that I need to install some type of protection device for reverse current or short circuited panel? I was hoping to avoid that.
What makes parallel more efficient for my system?
thank you
Quote from: pablo on June 05, 2016, 11:32:14 PM
"2P"?
If I go parallel, is it true that I need to install some type of protection device for reverse current or short circuited panel? I was hoping to avoid that.
What makes parallel more efficient for my system?
thank you
2P = two panels in parallel
it keeps the PV closer to one step above your 12v batteries. The farther the PV is from the battery voltage the less efficient the system will be.
If you have plans to have more than 2 strings you need protection as per the manufacturers specs, found on the back of the PV..
at 2 strings or 2 individual panels you can combine without CB's,
BUT it is quite beneficial to have them if you are doing any work on the system and you want to power down part of your setup for testing , rewiring etc...
Because you have only two panels why not experiment as it is only one lot of connections for the panels.
See what voltage drops you get from each connection config!
Your VOC for the panels is high enough even allowing for some losses to do this.
No matter how you config your panels on a normal day they should have a high enough input voltage to keep your batteries
charged. Just try it test them wired series and then parallel.
You will soon see if there is any advantage for you either way.
What a great idea! Thanks.
I'm hoping to get back to this dang project next week. I had to take a week off from work to give it some proper attention. So, I'll probably be bombarding you guys with questions next week. :o