Eric has the idea spot on, I'll follow up with what a lot of off-gridders around here in N. Nevada had tutored me on. That is the losses and controlling them. Number one with a bullet is loss from throwing electrons down wires.. You know it from poe losses and it's a 100 times worse in solar applications. The biggest gain through using serial panels is in reduction of current loss through the wires between the panels and to the charge controller. You would have to have monster wires to be as efficient as 3 amps down reasonably sized wires at 120 volts as 15 amps at 24. And as you go from the charge controller to the batteries and you eat away your 5 amps ( at 24 Volts? That is Big ) you still have 10 amps between the controller and your batteries. Get Very Large Cables, as large as the controller will accept. MPPT controllers are the ticket unless you have tracking arrays, in which case the guys here go back to pwm for better results. I haven't figured out why, they just show me the numbers that show it. MPPT controllers running in serial also have the advantage that you can mix and match your panels without losing the output of your large panels into the small ones..
Lastly we angle our panels in the winter to the lowest sun angles as that is when the transit is shortest and the need the greatest. Robert On 11/19/2013 09:18 PM, Eric Flanery wrote: > I'd replace the controller with a mppt model, wire the panels in series > (to 48v nominal), and leave the battery bank at 24v. > > Decoupling the panel voltage from the charging voltage let's you start > charging a bit earlier, and keep charging a bit longer; plus mppt is a > bit more efficient than pwm. > > Most importantly, it let's you double your panels (which is your best > bet overall), without having to increase the gauge of your wiring. > > --Eric > > > Sent from my Samsung Galaxy Note® 3 > > > -------- Original message -------- > From: Mike Lyon > Date:11/19/2013 8:29 PM (GMT-08:00) > To: WISPA General List > Subject: Re: [WISPA] Solat panels: series or parallel? > > And it has about a 5 amp load... > > > >> On Nov 19, 2013, at 20:23, Gary Garrett <ggarr...@nidaho.net> wrote: >> >> You probably need more Sun, or less load. >> It sounds like you have it wired correctly. >> The panels should tilt south about the same angle as your Lattitude. >> Up here on the canadian border we are at 48 degrees lattitude so the >> panels tilt about 45 degrees. >> In the summer they lay flat. >> >> Gary >> >> >> >>> On 11/19/2013 7:43 PM, Mike Lyon wrote: >>> So i'm trying to figure out what i need more of, voltage or current? >>> >>> I have 2x, 300 watt, 24vdc panels. I currently have them wired in >>> parallel to a Morningstar SS20L-24 which in turn is hooked up to 4 >>> banks of 2x 12vdc deep cycle batteries (for a 24vdc system). I plan on >>> replacing these batteries soon with UB4Ds or something similiar. >>> >>> What would be best to keep these beasts charged? The solar panels >>> wired in series or parallel? >>> >>> Thanks, >>> Mike >>> _______________________________________________ >>> Wireless mailing list >>> Wireless@wispa.org >>> http://lists.wispa.org/mailman/listinfo/wireless >> >> _______________________________________________ >> Wireless mailing list >> Wireless@wispa.org >> http://lists.wispa.org/mailman/listinfo/wireless > _______________________________________________ > Wireless mailing list > Wireless@wispa.org > http://lists.wispa.org/mailman/listinfo/wireless > > > _______________________________________________ > Wireless mailing list > Wireless@wispa.org > http://lists.wispa.org/mailman/listinfo/wireless > _______________________________________________ Wireless mailing list Wireless@wispa.org http://lists.wispa.org/mailman/listinfo/wireless
