Rob Larson wrote:
The solution is an inverter per cell. All MPPT logic and power conditioning should be done in a small module (chip?) associated with each cell. The output from these small inverters would be combined on a panel to produce a single output from the panel. All panels should be connected in parallel. Shading, etc., would only affect the output from the shaded area. Multiple orientations would be a no-brainer. Additions to the system could be done in single panel units, and they would not need to be size matched to the rest of the units.
How complex/expensive is the only MPPT technology for a single panel?Would it be at all practical to make a micro MPPT controller that mounts on the back of a panel and outputs fixed 120VDC? The MX60 claims 99.1% converting to 48V at 40A. Turn off the MPPT tracking on the GT-3.0, lock the input to 120VDC and away you go. This would solve the different orientation issue for string inverters while letting the centralized inverter handle the grid-tie, conversion and certification issue.
Each panel could have two MC male connectors and two MC female plugs.
Sean