Minimum PV source size - Revision history

Alex: Text replacement - "[[Series and parallel" to "[[Series and parallel connections"

2021-03-02T06:41:17Z

Text replacement - "[[Series and parallel" to "[[Series and parallel connections"

Alex at 21:39, 19 January 2021

2021-01-19T21:39:49Z

Alex: /* Step 5: Determine charge controller type */

2021-01-05T15:44:17Z

Step 5: Determine charge controller type

Alex: /* Step 4: Determine minimum size of the PV source */

2021-01-05T14:54:52Z

Step 4: Determine minimum size of the PV source

Alex: /* Step 4: Determine minimum size of the PV source */

2021-01-05T14:19:14Z

Step 4: Determine minimum size of the PV source

Alex at 14:06, 5 January 2021

2021-01-05T14:06:16Z

Alex: /* Step 5: Determine charge controller type */

2021-01-05T00:52:30Z

Step 5: Determine charge controller type

Alex: /* Step 2: Charge controller efficiency parameter */

2021-01-05T00:50:29Z

Step 2: Charge controller efficiency parameter

Alex at 00:49, 5 January 2021

2021-01-05T00:49:55Z

Alex: Text replacement - "[[Lead acid batteries" to "[[Lead acid battery"

2021-01-01T20:46:12Z

Text replacement - "[[Lead acid batteries" to "[[Lead acid battery"

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 The size of the [[PV module|PV source]], which is determined based upon the [[Load evaluation|load evaluation]] and [[Weather and solar resource evaluation|weather and solar resource evaluation]] will determine the necessary size of the charge controller. The charge controller must be selected at the same time as the PV source as the [[Charge controller#Charge controller types|charge controller type]] - PWM or MPPT - will also determine the possible configurations of PV modules.
-In this phase of the design process, more than in any other phase, it is necessary to explore different designs using [[PV module|PV module]], [[Series and parallel|series and parallel wiring configurations]], and [[Charge controller|charge controllers]] in order to achieve the highest performance at the lowest cost possible. This phase may have to be performed several times.
+In this phase of the design process, more than in any other phase, it is necessary to explore different designs using [[PV module|PV module]], [[Series and parallel connections|series and parallel wiring configurations]], and [[Charge controller|charge controllers]] in order to achieve the highest performance at the lowest cost possible. This phase may have to be performed several times.
 An off-grid PV system that depends upon the PV as its single charging source requires an array that is sufficiently sized to be able to generate sufficient energy to both meet the energy needs of the users and to recharge the [[Energy storage|energy storage system]] under less-than-ideal conditions. Any sizing decisions should therefore lean towards a larger PV source.

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 In this phase of the design process, more than in any other phase, it is necessary to explore different designs using [[PV module|PV module]], [[Series and parallel|series and parallel wiring configurations]], and [[Charge controller|charge controllers]] in order to achieve the highest performance at the lowest cost possible. This phase may have to be performed several times.
-An off-grid PV system that depends upon the PV as its single charging source requires an array that is sufficiently sized to be able to generate sufficient energy to both meet the energy needs of the users and to recharge the [[Energy storage|energy storage system]] under less-than-ideal conditions. Any sizing decisions should therefore lean towards an oversized PV source.
+An off-grid PV system that depends upon the PV as its single charging source requires an array that is sufficiently sized to be able to generate sufficient energy to both meet the energy needs of the users and to recharge the [[Energy storage|energy storage system]] under less-than-ideal conditions. Any sizing decisions should therefore lean towards a larger PV source.
 ====Step 1: Deteremine PV source loss parameters====

← Older revision		Revision as of 15:44, 5 January 2021
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	====Step 5: Determine charge controller type====		====Step 5: Determine charge controller type====
−	All charge controllers lose a certain percentage of all energy that is produced as heat as it is transferred to the [[Energy storage\|energy storage system]] and [[:Category:Loads\|loads]]. For both charge controller types a value of .98 (98% efficient) can be used.
	There are two different charge controller types - pulse width modulation (PWM) and maximum power point tracking (MPPT) - each of which has advantages and disadvantages that are are detailed in [[Charge controller#Charge controller types\|Charge controller types]]. Two separate designs may be performed with each type of charge controller to determine the best system design. The current and voltage rating of the charge controller will be determined when in either [[PWM charge controller sizing and selection]] or [[MPPT charge controller sizing and selection]].		There are two different charge controller types - pulse width modulation (PWM) and maximum power point tracking (MPPT) - each of which has advantages and disadvantages that are are detailed in [[Charge controller#Charge controller types\|Charge controller types]]. Two separate designs may be performed with each type of charge controller to determine the best system design. The current and voltage rating of the charge controller will be determined when in either [[PWM charge controller sizing and selection]] or [[MPPT charge controller sizing and selection]].

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 {| class="wikitable" border=1 style="width: 80%;"
 ! style="width: 20%"|Minimum PV source size
-! style="text-align:left;"| = [[Load and solar resource comparison|Design daily Watt-hours required]] ÷ [[Load and solar resource comparison|Design insolation]]    ÷ Total PV source loss parameter (Step 1) ÷ Charge controller efficiency parameter (Step 2) ÷ Energy storage efficiency parameter (Step 3)
+! style="text-align:left;"| = [[Load and solar resource comparison|Design daily watt-hours required]] ÷ [[Load and solar resource comparison|Design daily insolation]] ÷ Total PV source loss parameter (Step 1) ÷ Charge controller efficiency parameter (Step 2) ÷ Energy storage efficiency parameter (Step 3)
 |}

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 {| class="wikitable" border=1 style="width: 80%;"
 ! style="width: 20%"|Minimum PV source size
-! style="text-align:left;"| = [[Load and solar resource comparison|Design daily Watt-hours required]] ÷ [[Load and solar resource comparison|Design insolation]]    ÷ Total PV source loss parameter (Step 1) ÷ Charge controller efficiency parameter (Step 2) ÷ Energy storage efficiency parameter (Step 4)
+! style="text-align:left;"| = [[Load and solar resource comparison|Design daily Watt-hours required]] ÷ [[Load and solar resource comparison|Design insolation]]    ÷ Total PV source loss parameter (Step 1) ÷ Charge controller efficiency parameter (Step 2) ÷ Energy storage efficiency parameter (Step 3)
 |}

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 *'''Wiring loss parameter:''' Parameter that accounts for the loss of voltage due resistance in DC system wiring. The actual value depends upon the system design. Total DC wiring losses - roundtrip from [[PV module|PV source]] to [[Energy storage|energy storage system]] - should be kept below 4%. A value of .96 (4% loss) is recommended for this parameter.
 *'''Module mismatch parameter:''' Parameter that accounts for the loss of production that results from PV modules having different characteristics that result from manufacturing inconsistencies. This only applies for systems that have more than 1 PV module. The proper value varies depending upon the module used, but a value of .98 (2% loss) is recommended for this parameter.<ref name="NRELderate"/>
 *'''PV source temperature loss parameter:''' Parameter that accounts for losses that result from PV module cell temperatures in excesss of the [[PV module#Standard test conditions|standard test condition]] value of 25°C, which are common except in the coolest locations on earth. Cell temperatures are generally 10C-30ºC above ambient temperatures in full sunlight, therefore ambient temperatures must be around 0ºC for cell temperatures to be at 25ºC. The temperature of a PV module depends upon the climate, [[Insolation|insolation]], and how the module is mounted. PV module manufacturers provide a loss coefficient - typically called Temperature coefficient of max power and measured in %/°C - on the specifications sheet of each module that can be used to estimate losses based upon the conditions at the site. The value from the specifiction sheet of a module can be used in these calculations if a module has been chosen, but a standard average value of (-.48%/°C) will work for both poly and monocrystalline modules.<ref name="homer1">HOMER - PV Temperature Coefficient of Power https://www.homerenergy.com/products/pro/docs/latest/pv_temperature_coefficient_of_power.html</ref>
 ::{| class="wikitable" border=1 style="width: 80%;"
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 {| class="wikitable" border=1 style="width: 80%;"
 ! style="width: 20%"|Minimum PV source size
-! style="text-align:left;"| = [[Load and solar resource comparison|Design daily Watt-hours required]] ÷ [[Load and solar resource comparison|Design insolation]]    ÷ Total PV source loss parameter (Step 1) ÷ Charge controller efficiency parameter (Step 3) ÷ Energy storage efficiency parameter (Step 4)
+! style="text-align:left;"| = [[Load and solar resource comparison|Design daily Watt-hours required]] ÷ [[Load and solar resource comparison|Design insolation]]    ÷ Total PV source loss parameter (Step 1) ÷ Charge controller efficiency parameter (Step 2) ÷ Energy storage efficiency parameter (Step 4)
 |}

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 ====Step 5: Determine charge controller type====
 All charge controllers lose a certain percentage of all energy that is produced as heat as it is transferred to the [[Energy storage|energy storage system]] and [[:Category:Loads|loads]]. For both charge controller types a value of .98 (98% efficient) can be used.
-There are two different charge controller types - pulse width modulation (PWM) and maximum power point tracking (MPPT) - each of which has advantages and disadvantages that are are detailed in [[Charge controller#Charge controller types|Charge controller types]].  An MPPT charge controller will outprudce a PWM charge controller under most conditions. Two separate designs may be performed with each type of charge controller to determine the best system design. The actual size of the charge controller will be determined when [[PWM charge controller sizing and selecting the [[PWM charge controller sizing and selection|PWM]] or [[MPPT charge controller sizing and selection|MPPT]]. The charge controller will be sized further on, but a charge controller type should be selected at this point.
+There are two different charge controller types - pulse width modulation (PWM) and maximum power point tracking (MPPT) - each of which has advantages and disadvantages that are are detailed in [[Charge controller#Charge controller types|Charge controller types]]. Two separate designs may be performed with each type of charge controller to determine the best system design. The current and voltage rating of the charge controller will be determined when in either [[PWM charge controller sizing and selection]] or [[MPPT charge controller sizing and selection]].
 :'''PWM:'''<br />
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 :*Minimum PV source voltage: depends upon nominal voltage and charge controller type
 :*Maximum PV source current: up to 100A+
 ==Notes/references==
 <references/>
 National Renewable Energy Laboratory - [https://www.nrel.gov/docs/fy12osti/54200.pdf Understanding Light-Induced Degradation of c-Si Solar Cells]

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 ====Step 2: Charge controller efficiency parameter====
-All charge controllers lose a certain percentage of all energy that is produced as heat as it is transferred to the [[Energy storage|energy storage system]] and [[:Category:Loads|loads]]. For both charge controller types a value of .98 (98% efficient) can be used.
+All charge controllers lose a certain percentage of all energy that is produced as heat as it is transferred to the [[Energy storage|energy storage system]] and [[:Category:Loads|loads]]. For both PWM and MPPT charge controllers a value of .98 (98% efficient) can be used.
 ====Step 3: Energy storage efficiency parameter====

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 All [[Energy storage|energy storage systems]] lose a percentage of all energy produced to heat as it is stored and released to power [[:Category:Loads|loads]].
 :Energy storage efficiency parameter values for lead acid battery types:
-:*[[Lead acid batteries#Flooded lead acid (FLA)|Flooded lead acid (FLA) batteries ]]: .75 (75% efficient)<ref name="trojanpaper"> Trojan Battery Company - Selecting the Proper Lead-Acid Technology http://www.trojanbattery.com/pdf/Trojan_AGMvsFloodedvsGel_121718.pdf</ref>
+:*[[Lead acid battery#Flooded lead acid (FLA)|Flooded lead acid (FLA) batteries ]]: .75 (75% efficient)<ref name="trojanpaper"> Trojan Battery Company - Selecting the Proper Lead-Acid Technology http://www.trojanbattery.com/pdf/Trojan_AGMvsFloodedvsGel_121718.pdf</ref>
-:*[[Lead acid batteries#Valve-regulated lead acid (VRLA)|Valve-regulated lead acid (VRLA) batteries]]: .85 (85% efficient)<ref name="trojanpaper"/>
+:*[[Lead acid battery#Valve-regulated lead acid (VRLA)|Valve-regulated lead acid (VRLA) batteries]]: .85 (85% efficient)<ref name="trojanpaper"/>
 ====Step 5: Determine minimum size of the PV source====