i watched other channels I did not understand temperature coefficient. you made me understand thank you so much! I am walking tall now, head is held high!
Thank you for explaining this, I just had 10k system installed and turned on in March of this year in Phoenix AZ. In April my system was producing 64hwh for the full day, but thisnlast week at over 110 degrees, the panels have dropped to 55kwh, and I thought they would do better. I was about to blow up the crappy solar company OnPoint Solar - worst company I have ever had to deal with. This new issue was going to make things worse. Thanks, you saved them another call.
The inverter went over voltage in Kalamazoo one cold winter. The warranty was voided and the installer was responsible for buying the new inverter. The maximum input voltage of the inverter was 1000V. The PV module specifications at STC were: power = 245W, Vmp = 30.1V, Imp = 8.2A, Voc = 37.7V, Isc = 8.7A. The temperature coefficient for the panel was -0.121. There were 24 modules per PV source circuit. How cold did it get when the inverter got to be 1000V dc?
Not sure if you temp coefficient figure is right. For example 250 watt panel from Canadian Solar (CS6P-250 I 255P) has a temp coefficient Voc of -0.34 %/℃. Using this in my calculation temperature got down to as low as -6 degrees C ( a little over 1000 VocMAX) see link to data sheet www.mrsolar.com/content/pdf/Canadian/CS6P-250P255P.pdf Hope this helps.
Hi I've got a Question , I need help in solving this Tempreture Co-efficient Calculation : If the temperature Co-efficient of a module is -150mv/°C at STC And the Vmp is 38V at STC Calculate the Vmp of the module at 70°C
There is no linear ratio between VOC and VMPP but most solar modules will have a very small temperature co-efficient of ISC which means the effects on the panel current is minimal due to temperature change. We work on an upper limit of 70 degrees as you mentioned. Panels are tested and rated under STC (standard test conditions), which is 25 degrees Celsius with 1000W/sqm of sunlight and Air Mass of 1.5. This means that there is a 45 degree difference between the STC and the upper temperature limit As current doesn’t fluctuate much due to temperature it is reasonably safe to use temperature co-efficient of PMAX to determine voltage gain/loss due to the effects of temperature. Let’s say it is -0.46%/C. This means that for every degree above 25 C the VMPP will fall by 0.46% of 38V, so the calculation to determine voltage (and power) losses at 70 degrees would be, 45 (degrees difference between 25 and 70) x 0.46 = 20.7% loss. The VMPP of 38V would now become 38 / 100 x (100-20.7) = 30.134V Hope this helps!
Ive done the calculation according to the PV solar Tempreture Co-efficient method the Answer is (B) 35.95 Vmp The steps is as Follows: Step1 : You must convert the -150millivolts to Voltage -150 millivots = -0.15 Volts Step 2 : The 0.15 Volts will automatically be changed to 0.15% Step 3 : Effeciancy of Temp 38 Stc (standard test conditions) of a Pv solar pannel according to the Question = 38 × 0.15% = 0.057 Volts/°C Step 4 : Information that we have Stc = 25°C ( standard test conditions ) for any solar panel Higest Range Summer = 70° (acording to the question) Volts per degree °C = 0.057 V/°C Voltage Summer drop : = ∆t (peak temp) × 0.057 =( 70°- 25°) × 0.057 = 45 × 0.057 = 2.565 = 3 Voltage Drop Step 5: Summer Volts= Stc -Voltdrop = 38 - 3 = 35 Vmp
i watched other channels I did not understand temperature coefficient. you made me understand thank you so much! I am walking tall now, head is held high!
We're glad to hear that!! :)
Thank you for explaining this, I just had 10k system installed and turned on in March of this year in Phoenix AZ. In April my system was producing 64hwh for the full day, but thisnlast week at over 110 degrees, the panels have dropped to 55kwh, and I thought they would do better. I was about to blow up the crappy solar company OnPoint Solar - worst company I have ever had to deal with. This new issue was going to make things worse. Thanks, you saved them another call.
Our pleasure.
The inverter went over voltage in Kalamazoo one cold winter. The warranty was voided and the installer was responsible for buying the new inverter. The maximum input voltage of the inverter was 1000V. The PV module specifications at STC were: power = 245W, Vmp = 30.1V, Imp = 8.2A, Voc = 37.7V, Isc = 8.7A. The temperature coefficient for the panel was -0.121. There were 24 modules per PV source circuit. How cold did it get when the inverter got to be 1000V dc?
Not sure if you temp coefficient figure is right.
For example 250 watt panel from Canadian Solar (CS6P-250 I 255P) has a temp coefficient Voc of -0.34 %/℃.
Using this in my calculation temperature got down to as low as -6 degrees C ( a little over 1000 VocMAX) see link to data sheet www.mrsolar.com/content/pdf/Canadian/CS6P-250P255P.pdf
Hope this helps.
Excellent. Thank you for your effort.
No problem For more nitty gritty detail stuff maybe become part of Greenwood Academy Community, see link www.greenwood.academy/
Great, learned a lot.
Hi I've got a Question , I need help in solving this Tempreture Co-efficient Calculation :
If the temperature Co-efficient of a module is -150mv/°C at STC
And the Vmp is 38V at STC
Calculate the Vmp of the module at 70°C
There is no linear ratio between VOC and VMPP but most solar modules will have a very small temperature co-efficient of ISC which means the effects on the panel current is minimal due to temperature change.
We work on an upper limit of 70 degrees as you mentioned.
Panels are tested and rated under STC (standard test conditions), which is 25 degrees Celsius with 1000W/sqm of sunlight and Air Mass of 1.5. This means that there is a 45 degree difference between the STC and the upper temperature limit
As current doesn’t fluctuate much due to temperature it is reasonably safe to use temperature co-efficient of PMAX to determine voltage gain/loss due to the effects of temperature. Let’s say it is -0.46%/C.
This means that for every degree above 25 C the VMPP will fall by 0.46% of 38V, so the calculation to determine voltage (and power) losses at 70 degrees would be, 45 (degrees difference between 25 and 70) x 0.46 = 20.7% loss.
The VMPP of 38V would now become 38 / 100 x (100-20.7) = 30.134V
Hope this helps!
Ive done the calculation according to the PV solar Tempreture Co-efficient method the Answer is (B) 35.95 Vmp
The steps is as Follows:
Step1 : You must convert the -150millivolts to Voltage
-150 millivots = -0.15 Volts
Step 2 : The 0.15 Volts will automatically be changed to 0.15%
Step 3 : Effeciancy of Temp
38 Stc (standard test conditions) of a Pv solar pannel according to the Question
= 38 × 0.15%
= 0.057 Volts/°C
Step 4 : Information that we have
Stc = 25°C ( standard test conditions ) for any solar panel
Higest Range Summer = 70° (acording to the question)
Volts per degree °C = 0.057 V/°C
Voltage Summer drop :
= ∆t (peak temp) × 0.057
=( 70°- 25°) × 0.057
= 45 × 0.057
= 2.565
= 3 Voltage Drop
Step 5: Summer Volts= Stc -Voltdrop
= 38 - 3
= 35 Vmp
@@ruanmeiring9798 Thank you for that :)!
Thanks for sharing
Our pleasure.
Power drop for polycrystalline and mono crystalline perc are same or different?
They are different but will need to look at the data sheet of the particular panels involved to find this information.
Dude are you serious?
Concerning?