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electrical:solar:output [2022/04/05 19:38]
frater_secessus [panel tilt] low sun caveat, typo 		electrical:solar:output [2022/10/19 10:34]
frater_secessus [Factors affecting solar panel output]
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 In practical terms, it's common to see a maximum of 75% of STC under good conditions, more under great conditions, and much less under poor solar conditions.  In practical terms, it's common to see a maximum of 75% of STC under good conditions, more under great conditions, and much less under poor solar conditions. 
 +
 +===== lack of demand =====
 +
 +Solar panels do not //push// power;  they respond to the [[electrical:solar:charge_controller|solar charge controller]]'s demand as it tries to meet your present needs.  When those needs are minimal (battery already charged, small loads) the controller and panels will be loafing.  
 +
 ===== charge controller type ===== ===== charge controller type =====
  
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 So a [[camping:snowbirding|snowbird]] who "chases 60" will be losing ~10% of panel output during the warmest part of the day.  Snowbirds chasing 70 will be losing ~13% of panel output. So a [[camping:snowbirding|snowbird]] who "chases 60" will be losing ~10% of panel output during the warmest part of the day.  Snowbirds chasing 70 will be losing ~13% of panel output.
 +
 +Note:  sub-freezing temperatures can push Voc/Vmp above their rated values.  If you will use solar in sub-freezing conditions leave plenty Voc headroom in your solar charge controller spec.
  
 Note: that [[hvac:insulation#heat_from_solar_panels|radiated heat from the underside of panels can raise temperatures inside the camper]]. Note: that [[hvac:insulation#heat_from_solar_panels|radiated heat from the underside of panels can raise temperatures inside the camper]].
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 ===== panel tilt ===== ===== panel tilt =====
  
-Insolation figures are given for flat surfaces((like flat-mounted panels)) but you can increase yield //when the sun is low in the sky// by keeping the panel more perpendicular to the sun. +Insolation figures are given for flat surfaces((like flat-mounted panels)).  This means //when the sun is low in the sky//((and skies are clear not overcast -- see below)) you may be able to increase solar yield by tilting the panels toward the sun.  In effect the panel is more perpendicular to the sun so it can capture maximal solar energy. 
  
 Pro: Pro:
  
-  * +30% daily harvest is possible, depending on the sun's position+  * +30% daily harvest is possible, depending on the sun's position((peak harvest may be much higher at some times but daily harvest is more applicable for offgrid vanlife))
   * can be used to increase harvest if roof space is maxxed (cannot add more panel)   * can be used to increase harvest if roof space is maxxed (cannot add more panel)
  
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 ===== cleanliness ===== ===== cleanliness =====
  
-According to Sandia lab testing, dusty panels cause a derating of about 5%.((FIXME citation))+[[https://www.sciencedirect.com/science/article/pii/S1876610214011874|According to lab testing]], dusty panels cause a derating of 5%-6%. 
 + 
 ===== further information ===== ===== further information =====
  
electrical/solar/output.txt · Last modified: 2024/02/21 11:49 by frater_secessus

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