If I run my panels in series, will this cause the system to get less total amps??

showme

I'm ready to wire my array up and use multiple series, but I started wondering, since this adds the voltages of the panels, but the amps stay the same, is it going to knock down the total rated watts the system is suppose to deliver? If the total amps, and in turn watts, remain the same throughout the series, I'd end up short in the end. Once again, am I missing something here?

Photowhit

showme said:

 Once again, am I missing something here?

Yep...

Amps are NOT power, Watts are power. The basic calculation is Amps x volts = Watts.

While your charge controller will recieve less amps, it will recieve the same Watts/power from the array.

The charge controller, The MPPT type, will effectively convert the Watts into the correct voltage and maximum amps that can be made available.

RCinFLA

Advantage of putting panels in series is you get more volts and less amps (same power) which means you can uses smaller gauge wire to carry the lower PV panel current.  Series panels must have closely matching Imp current.  Output will be the current of lowest current panel.  You can series stack different voltage panels if their Imp is close to same.  Parallel panels should match for Vmp voltage, but their Imp current does not have to be the same.

Disadvantage of series connected panels is if you have partial shading during the day you can lose more net output power Bypass diodes help reduce the loss if MPPT controller does not drop below its minimum voltage input level due to paritally shaded panel(s).

showme

Thank you for clarifying that for me. Although I consider myself at least reasonably intelligent, electricity's fine points and electrical math have always been a mystery to me, no matter how much I study it. (I took a semester's worth of classes at San Juan college in New Mexico, including DC circuits, electrical mathematics and electrical theory. Seems I'm missing a gene for this stuff. It gave me headaches trying to figure it out. It never did stick). Anyway, I was about to reverse my plan to wire them in series after I thought I might be losing power. The idea in my mind was that I was going to get 320w from 3 panels if the amps remain the same. I'm learning every day here.

littleharbor2

Off topic a little . Do you know anything about your NOS inverters? I have a SW 4024 I bought in the factory sealed box that was purchased, put in a warehouse and forgotten about. I figured it was a very rare find. It was 15 years old when I first commissioned it. Comforting knowing my inverter will likely outlive me.

showme

When I first started planning on getting solar (over 20 years ago) Trace Xantrex was cutting edge, so that is what I wanted. About 10 years ago, we found a great deal on a pallet of LG320's. I had just bought a complete set up from a guy that was moving and couldn't take it with him, which had a SW5548 on a Trace power panel, with most of the BOS there. I knew we would need two for enough power, and I found my two new ones on ebay. My wife and I went to New Mexico and bought the two NOS 5548's and two more new C40 pwm charge controllers and a remote read out screen. We've had all of this in storage until this summer when I excavated the holes for the pipes, and I just finished up setting the poles a month ago. What I know about them is what I've read in Homepower magazine and on the internet. I decided early on that I'm having the used one checked out and gone over, and I may just have all three done, at a place in White House, Tennessee that specializes in inverters and such, Trace Xantrex included.

Honestly, I'm considering selling them and getting a new Outback Radian set up instead of keeping them. I'm definitely not using the C40's, and will buy Midnite Solar Classics instead so I can use mppt's. Going into this without previous experience with a set up that has no customer service is little intimidating, even for a guy like me who thinks he can do anything. But I have heard time after time, even recently, about how these things are built like tanks and have lasted for decades, sometimes without any hitches. We'll see. All I know is we'll be living with it 24/7/365, so I want something that does it's job.