Differences

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

--- electrical:solar:output [2020/07/17 14:37]
frater_secessus [insolation] lumens
+++ electrical:solar:output [2021/01/27 19:27]
frater_secessus [Factors affecting solar panel output]
@@ Line 1: / Line 1: @@
 ====== Factors affecting solar panel output ======
-For various reasons **it will be a rare event when your panels put out their full rated power**.  One reason for this is **the power needs somewhere to go**;  unless you are in [[electrical:12v:charging#bulk_stage|Bulk stage]] or are running big loads you will not see the system making anything like it's capacity.  Even under perfect conditions.
+For various reasons **it will be a rare event when your panels put out their full rated power**.  One reason for this is **the power needs somewhere to go**;  unless you are in [[electrical:12v:charging#bulk_stage|Bulk stage]] or are running big loads //the power isn't needed// so //the power isn't generated//.
 The other big reason is that **power ratings are derived from testing under specific lab conditions**.  The standard lab test is at:
-  - cell temperature of 25C, which would be an ambient temperature of about 0C (freezing).  Panel voltage decreases significantly as cell temperature increases.
+  - //cell// temperature of 25C, which would be an //ambient// temperature of about 0C (freezing).  Panel voltage decreases significantly as cell temperature increases.
   - 1000w of insolation per square meter of panel.  That is the amount of sun when the sun is directly overhead on a clear day.  Insolation maps will estimate [[#insolation_maps|how much sun]] various regions get.((This is what a panel's //efficiency// refers to:  the percentage of 1000w the panel can harvest per square meter of surface area.))
@@ Line 57: / Line 57: @@
     * amount of atmosphere the rays have to penetrate (less at solar noon, more at other times or anytime sun is relatively lower on the horizon)
     * air quality:  \\ smoke((http://www.cheaprvliving.com/forums/showthread.php?tid=26592&pid=333826#pid333826)),((http://www.cheaprvliving.com/forums/showthread.php?pid=331627#pid331627))
+    * altitude (total irradiance ~+2.67%/1000')((https://www.sciencedirect.com/science/article/abs/pii/S1011134496000188))
 {{ http://img.mousetrap.net/misc/wattsunderconditions.jpg}}Based on [[https://en.wikipedia.org/wiki/Orders_of_magnitude_%28illuminance%29|lux measurements]], we can estimate how sky clarity/brightness affects the amount of power theoretically available to the panel.
 Takeaways:  overcast skies greatly reduce output, and there is no meaningful power available at sunrise/sunset.
+Also see [[opinion:frater_secessus:solar harvest|these anecdotal observations]].

RV and vandwellers wiki

User Tools

Site Tools

Differences

Page Tools