diy solar

diy solar

Real life temperature of solar panels

DaGoose13

New Member
Joined
Jul 28, 2021
Messages
140
Does anyone have some real life measurements of ambient vs cell temperature?

Trying to figure out if I'm better off with a lower output panel that I can have more of or a higher output panel over a broad range of temperatures (-15F to 105F) without having to reconfigure panels to keep it below voltage limits.
 
I'd look for cheapest $/watt.
Unfortunately, that may not help as if I go with a lower output panel, then I may have to get more mounts, inverters, etc and the cost savings goes out the window.

If I go with the highest output panels, then I get into the issue that I may have to do less panels, so not to over-voltage the system when it's cold out and may not be able to deliver the amount of power that I want/need.
 
You could safely overpanel by having one set of panels facing more easterly and another set facing more westerly. This gives you more useful solar hours over the course of the day but since not all of the panels will be near full power at the same time you are not maxing out the voltage.
 
You could safely overpanel by having one set of panels facing more easterly and another set facing more westerly. This gives you more useful solar hours over the course of the day but since not all of the panels will be near full power at the same time you are not maxing out the voltage.
I thought about that, but the array will be large and I'm not sure I want to make it that complex by having each group having some panels face different directions.
 
Both high and low power panels require consideration of their temperature coefficients.

PV panels convert sunlight to electrical power. Cheapest now are 0.50 to 0.60 /watt. You could get LONGI LR4-60HPB-350M (350 watt for $188).

That's 0.53/watt

These are 19.6 square feet in area producing 17.8 watts/SF.

That's about normal for the current "state of the art" for commercial retail panels.
 
Both high and low power panels require consideration of their temperature coefficients.

PV panels convert sunlight to electrical power. Cheapest now are 0.50 to 0.60 /watt. You could get LONGI LR4-60HPB-350M (350 watt for $188).

That's 0.53/watt

These are 19.6 square feet in area producing 17.8 watts/SF.

That's about normal for the current "state of the art" for commercial retail panels.
Understand that.

What I'm looking for is some real world measurements of cell temperature versus ambient temperature, so I can get a feel if a panel will be able to handle the temperature range that I'm looking at.
 
This is exactly what the temp coefficients are for listed on every panel so that you can calculate the effects of the ambient temperature on the panel.
 
It's largely irrelevant for what you're talking about.

In the sun a panel will always be much hotter than 105F and they're all more than capable of handing it.

As stated, if you really are convinced you need to worry about this for some reason the temperature coefficient should be on the specs of the panels you're looking at.
 
handle the temperature range that I'm looking at

Most panels are built to operate on planet earth. For example the LONGI LR4-60HPB-350M has an operating temperature range of -40C to 85 C.

-40 C is -40 F; 85 C is 185F: should be OK for your temperature range.
 
as long as you don’t go over the max voltage when it cold it should be ok .
My panes put out 41 volts and I have 3 in series so 123 v total I’m good for - 27 to -31
I don’t lose much power when it’s really hot plus I get charged up long before mid day .
Maybe in the tropics this could be a problem .
If I’m seeing - 27 on the weather report I turn off the solar at dark and turn it on when it warms up .
 
This is exactly what the temp coefficients are for listed on every panel so that you can calculate the effects of the ambient temperature on the panel.
I've already calculated with the STC coefficients and the NOCT temperature difference.

What I'm asking is if anyone has any real world (not test) data, so I can factor that in.
 
as long as you don’t go over the max voltage when it cold it should be ok .
My panes put out 41 volts and I have 3 in series so 123 v total I’m good for - 27 to -31
I don’t lose much power when it’s really hot plus I get charged up long before mid day .
Maybe in the tropics this could be a problem .
If I’m seeing - 27 on the weather report I turn off the solar at dark and turn it on when it warms up .
That's the problem I'm trying to avoid.

Want it to run all the time without having to intervene if the temperature is too cold and the voltage goes too high.
 
Easy Peezy just go to the mid nite controller site and punch in your # and it will give you the answer
 
I dont see -31 ever I think the coldest its been here in 100years is -24 so I’m good .
If i see a really cold forecast I just flip the solar off at nite and turn it on in the morning
I don’t have to do it . It’s not a big deal .
 
I would think you could use panels in the 40v range 3 in series .
The panels do have different requirements but this time of year I see about 100v 105v at 80o At 0 the voltage go up to 120 ish
I don’t really look at that number , once it’s figured out your done.
 
Back
Top