PV upgrade decision
Right to the point: should I upgrade to a bigger panel or to an mppt controller? More info for those that take the time to read: I have a 100 watt, 21 ish volt panel and a pwm controller right ...
Forum Discussion
KD4UPL wrote:
Did you look at the specs on the Sun Power panel? It's well over a 50v input and it's no where near the 9.5A you mention.
KD, his intended panel was by Solar World, 9A. With all these sun/solar names it can get confusing indeed.
It's interesting that SMK didn't chime in saying that with TS MPPT 45 they might as well get 3*235W from Solar Blvd, $150 a piece ;)...
I believe in old mantra "There is no such thing as too much solar". If controller harvested enough by noon with "too big" solar, it will happily take an afternoon nap. But when it's dark and wet, it will still make enough to keep juices flowing, while a smaller solar would mean starting a generator.
To further complicate the matter, - there is more than one way to skin a cat. 700W is just a hair over the limit for 45A MPPT, still doable. MPPT are tolerant to a little excess of input watts.
Similarly, 450-500W is doable with 30A MPPT. And here the Bogart 30A PWM combo comes to mind, with 4 or 5*100W panels in parallel - it's different from all other PWM because it can handle excess watts, clipping them off. You can get 100W for $100 from Home Depot, free shipping or pick it up.
2*250W in series with MPPT is easier though.
