Join Date: Mar 2012
Location: Portland, ME
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Re: solar recommendations
It is my understanding that polycrystalline or "thin film" panels are more shade tolerant than standard cells. Is it possible that they are superior in shady climates and boats with more shade issues?
It was also my understanding that if enough of the cells of a monocrystalline panel were shaded, the output would drop to zero because it was below charging voltage. (each cell contributes a finite amount of voltage). Is this shading issue solved with MPPT controllers?
Poly and thin film are two different things. Thin film are, in fact, more tolerant of diffuse radiation, though they have lower performance overall.
On any Mono or poly crystalline module, shading any one cell completely will drop the output of that string of cells to zero. Most modules (panels) consist of two or three parallel strings of cells so as few as three totally shaded cells will take the output to zero.
An MPPT controller will help when voltage is low because of poor sun angle etc, but if a cell is fully shaded it won't pass any current and so neither will that whole string. A charge controller can't help you around that.