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A load with resistance R=V/I equal to the reciprocal of this value draws the maximum power from the device. This is sometimes called the 'characteristic resistance' of the cell. This is a dynamic quantity that changes depending on the level of illumination, as well as other factors such as temperature and cell condition. Lower or higher resistance reduces power output. Maximum power point trackers utilize control circuits or logic to identify this point.
DC-DC Convertor:
About Solar Panels:
https://en.wikipedia.org/wiki/Maximum_power_point_tracking
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P(in) is taken as the product of the irradiance of the incident light, measured in W/m2 or in suns (1000 W/m^2), with the surface area of the solar cell [m^2].
Here’s a good video explaining solar optimizers: Note - optimizers are not always MPPTs, but the algorithm could be implemented on the optimizers. https://www.youtube.com/watch?v=E9NVLB_OYSU