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--- electrical:solar:panels [2024/05/28 16:36]
frater_secessus [Portable]
+++ electrical:solar:panels [2025/03/13 14:07] (current)
frater_secessus [efficiency] bold
@@ Line 87: / Line 87: @@
 ==== Portable ====
-While most panels are hard mounted horizontally on the roof of the van, portable folding portable solar panels have dropped in price and have some advantages.
+While most panels are hard mounted horizontally on the roof of the van, portable solar panels((folding, briefcase, framed or otherwise)) may have some advantages.
 [[https://www.amazon.com/portable-solar-panel/s?k=portable+solar+panel|Amazon search]]
@@ Line 106: / Line 106: @@
   * Questions exist about long-term durability
   * Possibility of panels getting stolen
+  * not all portables are weatherproof
+  * can be blown over by wind
@@ Line 143: / Line 145: @@
 ===== efficiency =====
-The formula for panel efficiency is simply rated watts / square meter.  A 20% efficient panel will make 200w per square meter under lab conditions (ie, 20% of the lab's 1000w standard).
+The formula for panel efficiency is simply [ rated kW / square meter ].  A 20% efficient panel will make 200w per square meter under lab conditions, ie, 20% of the lab's 1000w standard. (0.20kW per square meter)
-Higher efficiency doesn't mean the panel makes more power;  it means it makes more power from a given area.  100w is 100w, but you might be able to fit a 110w panel high-efficiency panel in the same space as a regular-efficiency panel.
+Higher efficiency doesn't mean the panel makes more power;  it means it makes **more power from a given area**.  100w is 100w, but you might be able to fit a 110w panel high-efficiency panel in the same space as a regular-efficiency panel.
 In general, mono has higher efficiency than poly, and poly has higher efficiency than thin film.
@@ Line 166: / Line 168: @@
 PV are generally rated by several criteria((http://www.kg4cyx.net/solar-panel-specifications-explained/))
-  * **Power (W, or Pmax)**:	190 Watts.  <- rated power in Watts under lab conditions.  You can derive **price-per-watt** by dividing $/watts.
+  * **Power (W, or Pmax)**:	190 Watts.  <- rated power in Watts under [[#stc_and_noct|standard testing conditions (STC)]].  You can derive **price-per-watt** by dividing $/watts.
-  * **Open Circuit Voltage (Voc)**:	36.00 Voc  <- Volts in full sun with no load.  In practice you will likely not see Voc when hooked to the controller, but **all parts of your solar installation need to be able to cope with the theoretical Voc**.  In serial arrays the Voc ratings are added.
+  * **Open Circuit Voltage (Voc)**:	36.00 Voc  <- Volts in full sun with no load.  In practice you will likely not see Voc when hooked to the controller, but **all parts of your solar installation need to be able to cope with the theoretical Voc**.  In serial arrays the Voc ratings are added.  Because [[https://rvwiki.mousetrap.net/doku.php?id=electrical:solar:output#solar_magnifiers|some scenarios can cause panel overvoltage]], it is common to multiply ''Voc x 1.2''((ie, 20% buffer)) to find the safe PV input limit.
   * **Short Circuit Current (Isc)**:	7.42 Isc  <- Amps in full sun when shorted.  Also theoretical, but **connectors and cables need to be sized to handle Isc**.
   * **Maximum Power Voltage (Vmp)**:	28.60 Vmp <- voltage at which max power is generated in lab conditions

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