Derating 24v Solar Panels?
I'm considering running two 250w/24v poly panels; tracked/pointed during spring/fall, and flat during the summer; thru the Tracer 3215BN 30a mppt controller. I can also get 200w/24v mono panels, local...
Forum Discussion
Fred,
I do not know if the Tracer 30a clips amps? The most it has seen is about 20a, so far, with the two 140w panels. But regardless, I'm not one to push the envelope on such things. Lots of folks here say the Tracer BN series is junk... although they have never actually used one, or even know someone who has? Strange... I can only assume their "opinion" is based solely on price? But either way, I do not want to test that theory by constantly pushing it to its limit. OTOH, if someone would like to send me a free unit, to test, I'll gladly smoke it; in the name of science, of course. :)
I was about to say, if I was doing it all over again... but the fact is, I am doing it all over again. I am switching from 12v pwm portable, to 24v mppt roof top, manually tracked. If I could, I would simply buy two 24v poly panels, in the 200-215w range, and not worry so much about overloading the mppt. But I have chosen to buy what's available locally... which is 250w poly's for $239 can, (~ $190 u.s.). The 12v/140w poly's cost me $145 can, locally, (~ $115 u.s.), and no shipping. Compare that to $239 + shipping... so over $300 u.s vs. $115 u.s.... ~3x the cost.
I already have a solar30 pwm and the Tracer 3215BN... both new this year, so I'm not about to start buying more controllers; although a 2nd solar30 would certainly work well in a paralleled controller set-up, so that is certainly an option for the summer months. But I need mppt for the spring/fall seasons, when cool cloudy days favour mppt.
I do not know if the Tracer 30a clips amps? The most it has seen is about 20a, so far, with the two 140w panels. But regardless, I'm not one to push the envelope on such things. Lots of folks here say the Tracer BN series is junk... although they have never actually used one, or even know someone who has? Strange... I can only assume their "opinion" is based solely on price? But either way, I do not want to test that theory by constantly pushing it to its limit. OTOH, if someone would like to send me a free unit, to test, I'll gladly smoke it; in the name of science, of course. :)
I was about to say, if I was doing it all over again... but the fact is, I am doing it all over again. I am switching from 12v pwm portable, to 24v mppt roof top, manually tracked. If I could, I would simply buy two 24v poly panels, in the 200-215w range, and not worry so much about overloading the mppt. But I have chosen to buy what's available locally... which is 250w poly's for $239 can, (~ $190 u.s.). The 12v/140w poly's cost me $145 can, locally, (~ $115 u.s.), and no shipping. Compare that to $239 + shipping... so over $300 u.s vs. $115 u.s.... ~3x the cost.
I already have a solar30 pwm and the Tracer 3215BN... both new this year, so I'm not about to start buying more controllers; although a 2nd solar30 would certainly work well in a paralleled controller set-up, so that is certainly an option for the summer months. But I need mppt for the spring/fall seasons, when cool cloudy days favour mppt.
