Solar Controllers--Don't be a Sucker! :(
Just got to say it again, how it is we are sitting here for five months off grid on solar with no problems at all (third season on solar like this), using the non-programmable, non-MPPT, solar control...
Forum Discussion
Dissimilar panels can actually wreak havoc with many MPPT controllers, reducing the difference between PWM and MPPT. MPPT gives you the maximum gain when the Vmpp is identical across all panels in the real world, at all lighting levels and temps. As soon as the system optimum voltage has to start being a compromise between different optimal voltages for different panels, the advantage power gain over simple PWM shrinks.
It is even worse when there are local maxes in the power curve that are not the system maximums due to dissimilar panels. Some MPPT controllers find the first or wrong local max, which is far from the Vmpp for the combined panels.
A slow MPPT controller can actually produce less power thn PWM when a cloud goes over head and it has the voltage set too high, unil the next scan cycle to find the power point.
The maximum yield MPPT system would have a different MPPT controller for each individual panel.
All that said, I still want one or more highly programmable MPPT controllers.
But they are not a panacea.
Jim
It is even worse when there are local maxes in the power curve that are not the system maximums due to dissimilar panels. Some MPPT controllers find the first or wrong local max, which is far from the Vmpp for the combined panels.
A slow MPPT controller can actually produce less power thn PWM when a cloud goes over head and it has the voltage set too high, unil the next scan cycle to find the power point.
The maximum yield MPPT system would have a different MPPT controller for each individual panel.
All that said, I still want one or more highly programmable MPPT controllers.
But they are not a panacea.
Jim
