PWM vs MPPT Test Results
Today (blue sky, not quite to STC at this date at this latitude 49.3N but almost according to the calculator on that) I was able to run a test on my 230w panel and Eco-Worthy 20a MPPT controller.
I could at last compare the amps I got with an equivalent 230w on PWM. Result was a slight MPPT advantage in amps. EG 9.2/10.07, 11.85/12.74, 13.44/15.32, and 14.50/16.65 going from am-high noon.
Comparison was with a 130w panel proportioned up to 230w which I have found to be valid in previous tests using eg, 200w (two 100w) in same location. I won't repeat all that proof here, so if you haven't seen that stuff before, just have to trust me on the PWM amps used to compare. :)
So--- just taking the MPPT performance at high noon with some measurements that may be of interest to MPPT experts (or not!)
230w Hanwha panel- specs Vmp-30, Imp-7.7, Voc- 37.0, Isc- 8.3
Conditions at test: Voc 35.0, Isc 8.92 Ambient temp 16C/60F Temp at back of panel (aimed at sun at high noon) 44C (using infrared therm.)
Array to controller voltage drop not connected-Voc only, 0.3v
Voltage drop array to controller with 16a to battery 0.4v
So actual measurements at high noon were:
- array voltage at controller 29.2,
-batt voltage 12.3, amps into battery 16.65,
-Eco-W watts reading 205w, so it uses batt v and the amps.
The Eco-W has a little fun program to compare MPPT with PWM at any time. It said MPPT 17.00, PWM 8.92, Efficiency 91%. Note that 8.92a is the same as the Isc I took at the panel when disconnected.
So bottom line is I got slightly more amps than with PWM. Whether that is "worth it" is very situational and not the topic, but these results might help individuals evaluate that for their own situations.
PS. For the geeks, with the battery voltage climbing and about an hour before high noon I got:
-batt v 13.4 and 15.32a , 205w, array v at controller-29.3
I then turned on a bunch of 12v stuff to lower the batt v to see if that made any difference. Got:
-batt v 12.7, 16.48a, 210w, array v at controller-29.0
While fiddling with the panel and changing batt loading, I saw the Eco-W readings get a little unstable-- one time saw 17.13a unfortunately it all settled quickly to the mid-16s for amps :)
Perhaps in two months when solar conditions peak for the solstice, I will see more amps at high noon. I don't know if the test today shows there is "room to grow" for that or not, but maybe some experts could tell that from the above measurements.
I could at last compare the amps I got with an equivalent 230w on PWM. Result was a slight MPPT advantage in amps. EG 9.2/10.07, 11.85/12.74, 13.44/15.32, and 14.50/16.65 going from am-high noon.
Comparison was with a 130w panel proportioned up to 230w which I have found to be valid in previous tests using eg, 200w (two 100w) in same location. I won't repeat all that proof here, so if you haven't seen that stuff before, just have to trust me on the PWM amps used to compare. :)
So--- just taking the MPPT performance at high noon with some measurements that may be of interest to MPPT experts (or not!)
230w Hanwha panel- specs Vmp-30, Imp-7.7, Voc- 37.0, Isc- 8.3
Conditions at test: Voc 35.0, Isc 8.92 Ambient temp 16C/60F Temp at back of panel (aimed at sun at high noon) 44C (using infrared therm.)
Array to controller voltage drop not connected-Voc only, 0.3v
Voltage drop array to controller with 16a to battery 0.4v
So actual measurements at high noon were:
- array voltage at controller 29.2,
-batt voltage 12.3, amps into battery 16.65,
-Eco-W watts reading 205w, so it uses batt v and the amps.
The Eco-W has a little fun program to compare MPPT with PWM at any time. It said MPPT 17.00, PWM 8.92, Efficiency 91%. Note that 8.92a is the same as the Isc I took at the panel when disconnected.
So bottom line is I got slightly more amps than with PWM. Whether that is "worth it" is very situational and not the topic, but these results might help individuals evaluate that for their own situations.
PS. For the geeks, with the battery voltage climbing and about an hour before high noon I got:
-batt v 13.4 and 15.32a , 205w, array v at controller-29.3
I then turned on a bunch of 12v stuff to lower the batt v to see if that made any difference. Got:
-batt v 12.7, 16.48a, 210w, array v at controller-29.0
While fiddling with the panel and changing batt loading, I saw the Eco-W readings get a little unstable-- one time saw 17.13a unfortunately it all settled quickly to the mid-16s for amps :)
Perhaps in two months when solar conditions peak for the solstice, I will see more amps at high noon. I don't know if the test today shows there is "room to grow" for that or not, but maybe some experts could tell that from the above measurements.
