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opinion:frater_secessus:solar_harvest

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opinion:frater_secessus:solar_harvest [2023/02/17 15:17]
frater_secessus [observations] 		opinion:frater_secessus:solar_harvest [2023/02/17 15:20] (current)
frater_secessus [correlation with available direct light]
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 This is harder to grasp and compute, but increases accuracy by factoring in location, time, etc.((It cannot account for //indirect// light by refraction, reflection,etc. The contribution of indirect light is considered to be +15% in clear skies.)) This is harder to grasp and compute, but increases accuracy by factoring in location, time, etc.((It cannot account for //indirect// light by refraction, reflection,etc. The contribution of indirect light is considered to be +15% in clear skies.))
  
-1.  find solar zenith angle with app or calculator +  -  find solar zenith angle with app or calculator 
-1.  derive cosine of the above; this is the percentage of direct sunlight landing on a flat surface +  -  derive cosine of the above; this is the percentage of direct sunlight landing on a flat surface 
-1.  multiply this value by panel wattage +  -  multiply this value by panel wattage 
-1.  the result is the theoretical direct light available at that time/place under clear skies.((since MPPT-based system losses typically are -15% and indirect lighting is +15%, an MPPT-based system might make this direct-light power level under clear skies.)) +  - the result is the theoretical direct light available at that time/place under clear skies.((since MPPT-based system losses typically are -15% and indirect lighting is +15%, an MPPT-based system might make this direct-light power level under clear skies.))  
 + 
 +I have observed the following cosine-based direct light percentages: 
 + 
 +  * clear skies:   98% of theoretical direct sun 
 +  * bright overcast skies (shadows thrown):  82% of theoretical direct sun 
 +  * overcast: 58% of theoretical direct sun 
  
  
opinion/frater_secessus/solar_harvest.1676665040.txt.gz · Last modified: 2023/02/17 15:17 by frater_secessus

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