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electrical:solar:overpaneling [2022/10/28 16:29]
frater_secessus [vs. charge controller] victron quote 		electrical:solar:overpaneling [2023/11/22 10:31] (current)
frater_secessus [vs. charge controller]
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 The overpaneled system's power output bell curve is //shifted upwards// and cut off by the controller when it reaches its limits.  This is known as clipping, trimming, or clamping due to the "flat top" appearance of the overpaneled output curve. The overpaneled system's power output bell curve is //shifted upwards// and cut off by the controller when it reaches its limits.  This is known as clipping, trimming, or clamping due to the "flat top" appearance of the overpaneled output curve.
  
-With modest overpaneling the clipping is relatively minor.  Victron notes that:+With appropriate overpaneling the clipping is relatively minor.  Victron notes that:
  
->> Generally total energy harvested from a 130% panel oversizing results in less than 1% annual energy loss. -- [[https://www.victronenergy.com/blog/2014/03/28/matching-victron-energy-solar-modules-to-the-new-mppt-charge-regulators/source]]+>> Generally total energy harvested from a 130% panel oversizing results in less than 1% annual energy loss. -- [[https://www.victronenergy.com/blog/2014/03/28/matching-victron-energy-solar-modules-to-the-new-mppt-charge-regulators/|source]]
  
  
 +==== theory ====
  
-**Example:**  Consider the image to the right.((The image is that of a different PV-related configuration but it works for our purposes.)) The smaller/interior bell curve is the normally paneled configuration. \\ +Consider the image to the right.((The image is that of a different PV-related configuration but it works for our purposes.)) The smaller/interior bell curve is the normally paneled configuration. \\ 
 The larger/exterior curve is the overpaneled configuration. \\   The larger/exterior curve is the overpaneled configuration. \\  
 The striped area is the peak power "clipped" by the controller when the controller is overpaneled.  \\  The striped area is the peak power "clipped" by the controller when the controller is overpaneled.  \\ 
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   * you spend time in partial shade   * you spend time in partial shade
   * you want to use a smaller controller instead of jumping up to the next size.  Example, 43A max output and your choices are 40A or 60A controllers.   * you want to use a smaller controller instead of jumping up to the next size.  Example, 43A max output and your choices are 40A or 60A controllers.
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 +==== example ====
 +
 +Let's say you want to adhere to Victron's 10-30% overpaneling approach.  Working backwards, their model appears to use 14.2v Vbatt as a constant.  
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 +  * 500w / 14.2v = 35.2A. 
 +  * 35.2A on a 30A MPPT is    17.3% overpaneled:  ( (35.2 - 30) / 30 = 0.173)
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 Since the underbanked system has less capacity will reduce your actual [[electrical:solar:sizing#your_reserve_needs|reserve days of power]] to some extent.  But during daytime there is //some// solar power coming in and an overpaneled configuration will harvest relatively more power in sub-optimal conditions.  The smaller bank will get through Bulk and well into Absorption faster, too. This will help extend the //effective// reserve days of power. Since the underbanked system has less capacity will reduce your actual [[electrical:solar:sizing#your_reserve_needs|reserve days of power]] to some extent.  But during daytime there is //some// solar power coming in and an overpaneled configuration will harvest relatively more power in sub-optimal conditions.  The smaller bank will get through Bulk and well into Absorption faster, too. This will help extend the //effective// reserve days of power.
 +
 +Further reading:
 +
 +  * [[electrical:solar:slim_reserve|slim reserves]]
  
electrical/solar/overpaneling.1666988944.txt.gz ยท Last modified: 2022/10/28 16:29 by frater_secessus

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