Microinverters can’t be harmed by overdriving with higher-powered panels than they are rated for. The MPPT just sarurates during the highest-power part of the day and potential power is lost (by the Microinverter driving the panel at a higher voltage than Vmppt).
I assume the same is true of MPPT charge controllers but want to make sure.
I’m planning to connect 1.1kW of panels to a 30A MPPT charge controller rated for a maximum power output of 780W when charging a 24V battery.
I typically max out at ~75% of peak panel output, so 1.1kW of theoretical peak output should translate to ~825W of actual peak output.
I’ll lose about 30W to wiring losses (3.4%) meaning about 795W will be available to the charge controller.
The charge controller maxes out at 780W, meaning it will decrease voltage a bit below Vmppt to decrease total charge power to 780W and ~2% of the potential power output from the panels will be wasted (again, only during the brightest peak-output part of the day).
Do I have this correct? Is this how MPPT charge controllers throttle-back PV power output (either because they have maxed out or the battery is charged an no more power is needed).
The only thing I’m a bit confused about is that current only gets driven to zero by driving voltage to Voc, so perhaps MPPTs throttle by increasing voltage (and decreasing current) rather than decreasing voltage (and increasing current)?
I assume the same is true of MPPT charge controllers but want to make sure.
I’m planning to connect 1.1kW of panels to a 30A MPPT charge controller rated for a maximum power output of 780W when charging a 24V battery.
I typically max out at ~75% of peak panel output, so 1.1kW of theoretical peak output should translate to ~825W of actual peak output.
I’ll lose about 30W to wiring losses (3.4%) meaning about 795W will be available to the charge controller.
The charge controller maxes out at 780W, meaning it will decrease voltage a bit below Vmppt to decrease total charge power to 780W and ~2% of the potential power output from the panels will be wasted (again, only during the brightest peak-output part of the day).
Do I have this correct? Is this how MPPT charge controllers throttle-back PV power output (either because they have maxed out or the battery is charged an no more power is needed).
The only thing I’m a bit confused about is that current only gets driven to zero by driving voltage to Voc, so perhaps MPPTs throttle by increasing voltage (and decreasing current) rather than decreasing voltage (and increasing current)?