Differences

This shows you the differences between two versions of the page.

--- electrical:solar:shading [2020/03/17 15:49]
frater_secessus [Partial shading]
+++ electrical:solar:shading [2020/03/17 16:15]
frater_secessus [Partial shading]
@@ Line 5: / Line 5: @@
 Partial shading can have surprisingly dramatic effects on [[electrical:solar:output|panel output]]. The weirdest part is that //partial// shading can have more devastating effects on output than //full shading// like heavy overcast or evenly shaded forest canopies.
+===== reminder:  how panels work =====
+**Before we begin:** solar panels are "current sour
+ces";  their voltage pops up into the normal range in any kind of meaningful light(>= 20% [[electrical:solar:output|insolation]]) but current will suffer.
+Partial shading in this context means:
+  * light is falling on the panel
+  * but not evenly on the panel -- it is different on some cells
+To prevent power from rushing into the shaded cells panels have bypass diodes.  Basically the shaded panels get cut off, electrically speaking, to protect them.
-It works this way:
-  - partial shade causes //voltage differences// between cells
-  - electricity flows from higher-voltage areas to lower-voltage ones, so voltage differences would cause power to rush into the lower-voltage (shaded) cells
-  - overheating the shaded cell and possibly damaging it
-To prevent damage panel manufacturer's insert diodes between cells or strings of cells.  Partial shading trips the diodes and effectively takes the shaded cells/strings offline for their own protection.

RV and vandwellers wiki

User Tools

Site Tools

Differences

Page Tools