Good topic. Whenever you are dealing with a variable power source, you need to make sure that everything connected to it can handle the maximum voltage that might be produced even if almost all of the time the voltage will be much lower. If the voltage gets high enough to force current through something that doesnt want current, that something is instantly fried.
Hey thanks for asking. You'll need to consider both open-circuit voltage and nominal (working) voltage. open-circuit voltage is used for safety and system voltage design, while working voltage is used to determine the array configuration and calculate the power output under operational conditions. Hope this helps.
Funny story on that actually. The day we shot this video our voltmeters (all of which are digital) were taken out to jobsites, so I drove to the nearby Home Depot and bought the cheapest voltmeter they had. None of the actual digital meters we use look this shiny 😅 But that's an interesting observation. Do you think we should reshoot this with a digital multimeter?
As the temperature of the solar panel increases, its output current increases exponentially, while the voltage output is reduced linearly. In fact, the voltage reduction is so predictable, that it can be used to accurately measure temperature. As a result, heat can severely reduce the solar panel's production of power. Great question, hope this helps a bit.
I just measured mine with my multi meter a while ago and while the spec sheet states it should be 45.18v they measured around 40.2v or so. But it is a cloudy day today (no sun) with the temp at 76F. Would that cause it to be lower than spec? Should I be concerned?
Yes, lack of sunlight and cloudy days can definitely change the measurements around. It's nothing to be concerned about, but I would track overall production over the next month just to see how the panel(s) are producing. 😃
Aren't solar panel warranties a scam? For example if I spend $1500 on panels and install them myself, that voids the warranty because I'm not a "pro", right?
Amazing video!! Is there harm in oversizing your solar panels to improve absorption on cloudy days? Eg a 650w panel. Will there be risk on a sunny day when 650 watt is actually absorbed by the panel when the inverter is only rated for 550 watt ? My panel has a built in solar charge controller.
In short, the inverters will never pull more power from the panels than they can handle. If shorting out an inverter remains a concern, the biggest cause of inverter failure and overproduction mainly comes from overuse in appliances, which is still a rare case. Hope this helps and thank you for the question!
Agreed. In the grand scheme of solar energy, VOC really has little play in it's importance. Overall, our Solar: 101 content aims to give the audience a grasp at more than just the benefits to solar. We talk about the standard spec sheets and test conditions for those that really want to "know their system". We're merely explaining the different terms and giving our educated opinion on which ones are important to consider. Thanks for your input!
@@solaredgepros i have watch it and still confused. if we do the math v*a=w then if we have a 200w panel why do we / the watts by the charge controller volts?there is a set volts and amps for the panel but we are taking a number that is with another device and making it part of the total of the panel. to me that makes no sense
Is VOC the voltage that the panel will send to the charge controller?
Great explanation, thanks so much for the video!
Good topic. Whenever you are dealing with a variable power source, you need to make sure that everything connected to it can handle the maximum voltage that might be produced even if almost all of the time the voltage will be much lower. If the voltage gets high enough to force current through something that doesnt want current, that something is instantly fried.
Could you release a video explaining pmax, vmp, imp, and isc?
Yes! We're working on it :)
Great informational video
Do I use the open voltage or working voltage when it comes to making a solar array
Hey thanks for asking. You'll need to consider both open-circuit voltage and nominal (working) voltage. open-circuit voltage is used for safety and system voltage design, while working voltage is used to determine the array configuration and calculate the power output under operational conditions. Hope this helps.
"With a digital multimeter" then shows an analog meter being used......... Yep. That builds my confidence.
Funny story on that actually. The day we shot this video our voltmeters (all of which are digital) were taken out to jobsites, so I drove to the nearby Home Depot and bought the cheapest voltmeter they had. None of the actual digital meters we use look this shiny 😅 But that's an interesting observation. Do you think we should reshoot this with a digital multimeter?
I notice temp.coeff. for Pmpp and Voc has a - symbol while Isc has a + symbol?? Is rise in temp. raise the amp?
As the temperature of the solar panel increases, its output current increases exponentially, while the voltage output is reduced linearly. In fact, the voltage reduction is so predictable, that it can be used to accurately measure temperature. As a result, heat can severely reduce the solar panel's production of power. Great question, hope this helps a bit.
@@solaredgepros Cool!👌
How does a solar panel manufacturer make the solar panel so it is exactly 100watts or 18volts??
I just measured mine with my multi meter a while ago and while the spec sheet states it should be 45.18v they measured around 40.2v or so. But it is a cloudy day today (no sun) with the temp at 76F. Would that cause it to be lower than spec? Should I be concerned?
Yes, lack of sunlight and cloudy days can definitely change the measurements around. It's nothing to be concerned about, but I would track overall production over the next month just to see how the panel(s) are producing. 😃
Aren't solar panel warranties a scam? For example if I spend $1500 on panels and install them myself, that voids the warranty because I'm not a "pro", right?
Amazing video!!
Is there harm in oversizing your solar panels to improve absorption on cloudy days?
Eg a 650w panel.
Will there be risk on a sunny day when 650 watt is actually absorbed by the panel when the inverter is only rated for 550 watt ?
My panel has a built in solar charge controller.
In short, the inverters will never pull more power from the panels than they can handle. If shorting out an inverter remains a concern, the biggest cause of inverter failure and overproduction mainly comes from overuse in appliances, which is still a rare case. Hope this helps and thank you for the question!
Many thanks!!
քʀօʍօֆʍ
voc is useless once you put a load on it you will never reach that voltage again. your vmp operating voltage will never get that high never.
Agreed. In the grand scheme of solar energy, VOC really has little play in it's importance. Overall, our Solar: 101 content aims to give the audience a grasp at more than just the benefits to solar. We talk about the standard spec sheets and test conditions for those that really want to "know their system". We're merely explaining the different terms and giving our educated opinion on which ones are important to consider. Thanks for your input!
@@solaredgepros I myself having a hard time understanding the math that goes with solar controller. To me the math does not add up.
I did a bit more digging and came across this video. Hope this helps - th-cam.com/video/Jkbs84sBHsg/w-d-xo.html
@@solaredgepros i have watch it and still confused. if we do the math v*a=w then if we have a 200w panel why do we / the watts by the charge controller volts?there is a set volts and amps for the panel but we are taking a number that is with another device and making it part of the total of the panel. to me that makes no sense