Solar QuotesHow does the Aussie heat affect your solar panel performance?
One of the main factors that makes Solar Power so popular over here (apart from the Aussie Pollies throwing wads of money at in in the form of Solar rebates and Solar Feed In Tariffs) is the fact that the Sun is so damn strong down here.
It’s not rocket science to work out why Solar Power hasn’t really taken off in less sunny climes like my homeland; grey, drizzly old England.
In fact the same 1.5kW system on a roof of my Mum’s quaint cottage in Northern England will produce 45% less energy than if it was on my roof here in Sunny Adelaide.
So does that mean the more sun the better, when it comes to generating Solar Power?
That would kind of make sense right?
Unfortunately, as with most things in this life, it is a bit more complicated than that.
In fact when it comes to solar power you can have too much sun.
Say What?!?
The problem is, most solar panels’ power outputs start to degrade if the temperature of the panel goes over about 25°C.
This is why, if you look at the specification label on a solar panel, most manufacturers quote the solar power output at a panel temperature of 25degC.
So does that mean that if it is 25°C outside and a clear blue sky then your panels will be performing to their rated output?
Err… no.
Because, if the air temperature outside is 25°C, that dark solar panel baking on your roof is going to be closer to 50°C.
So how much solar power will you be losing on a 25°C day if the panel manufacturer has quoted power output at a solar panel temperature of 25°C?
To work that out we need to know the solar panel’s “Max Power Temperature Coefficient”, which should be on the solar panel’s specification sheet.
A typical value for this is 0.4% per °C.
Which means that for every degree that the solar panel is above 25°C the power will fall 0.4%.
So on a cool 25°C day where the panel is cooking at 50°C, you will be losing 10% of your solar power.
Here’s the calc:
0.4% x (50°C -25°C) = 0.4% x 25°C = 10%
And on days when the mercury breaks 40°C you can be losing close to 20% of your solar power.
Which is why you can often find that on the hottest days those solar panels on your roof are actually producing less solar power than usual.
If you are looking for solar panels that perform well in hot Australian weather, then here’s a list of some popular solar panel brands and their temperature coefficients, the best performing (temperature-wise) are at the top. (If I’ve left out your favourite panel – let me know via the commments and I’ll get it added!)
| Manufacturer | Model | Temperature Coefficient (%/°C) |
| UniSolar | PVL-68 | -0.21 |
| UniSolar | PVL-124 | -0.21 |
| UniSolar | PVL-128 | -0.21 |
| UniSolar | PVL-136 | -0.21 |
| UniSolar | PVL-144 | -0.21 |
| Sanyo | HIT-195DA3 | -0.29 |
| Sanyo | HIT-190DA3 | -0.30 |
| Sanyo | HIT-205NKHA1 | -0.34 |
| Sanyo | HIT-210NKHA1 | -0.34 |
| Sanyo | HIT-215NKHA1 | -0.34 |
| SunPower | SPR-210-BLK | -0.38 |
| SunPower | SPR-215-WHT | -0.38 |
| SunPower | SPR-225-BLK | -0.38 |
| SunPower | SPR-230-WHT | -0.38 |
| SunPower | SPR-305-WHT | -0.38 |
| SunPower | SPR-310-WHT | -0.38 |
| SunPower | SPR-315-WHT | -0.38 |
| SunPower | SPR-318E-WHT-D | -0.38 |
| Canadian | CS6A-150PE | -0.42 |
| Canadian | CS6A-160PE | -0.42 |
| Canadian | CS6P-170PE | -0.42 |
| Kyocera | KD135GX-LPU | -0.42 |
| CEEG | SST 160-72M | -0.42 |
| CEEG | SST 165-72M | -0.42 |
| CEEG | SST 170-72M | -0.42 |
| CEEG | SST 265-72M | -0.42 |
| CEEG | SST 175-72M | -0.42 |
| CEEG | SST 270-72M | -0.42 |
| CEEG | SST 180-72M | -0.42 |
| CEEG | SST 275-72M | -0.42 |
| CEEG | SST 280-72M | -0.42 |
| CEEG | SST 235-60M | -0.42 |
| CEEG | SST 185-72M | -0.42 |
| CEEG | SST 285-72M | -0.42 |
| CEEG | SST 240-60M | -0.42 |
| CEEG | SST 245-60M | -0.42 |
| CEEG | SST 250-60M | -0.42 |
| Canadian | CS6A-160P | -0.43 |
| Canadian | CS6A-170P | -0.43 |
| Canadian | CS6A-180P | -0.43 |
| Canadian | CS6P-180PE | -0.43 |
| Canadian | CS6P-190PE | -0.43 |
| Canadian | CS6P-200P | -0.43 |
| Canadian | CS6P-200PE | -0.43 |
| Canadian | CS6P-210P | -0.43 |
| Canadian | CS6P-220P | -0.43 |
| Canadian | CS6P-230P | -0.43 |
| Evergreen | ES-A-200-fa2 | -0.43 |
| Evergreen | ES-A-200-fa3 | -0.43 |
| Evergreen | ES-A-205-fa2 | -0.43 |
| Evergreen | ES-A-205-fa3 | -0.43 |
| Evergreen | ES-A-210-fa2 | -0.43 |
| Evergreen | ES-A-210-fa3 | -0.43 |
| Evergreen | ES-A-215-fa2 | -0.43 |
| Evergreen | ES-A-215-fa3 | -0.43 |
| Hyundai | HiS-M215SG | -0.43 |
| Hyundai | HiS-M194SF | -0.43 |
| Hyundai | HiS-M218SG | -0.43 |
| Hyundai | HiS-M197SF | -0.43 |
| Hyundai | HiS-M221SG | -0.43 |
| Hyundai | HiS-M200SF | -0.43 |
| Hyundai | HiS-M224SG | -0.43 |
| Hyundai | HiS-M203SF | -0.43 |
| Hyundai | HiS-M227SG | -0.43 |
| Hyundai | HiS-M206SF | -0.43 |
| Hyundai | HiS-M230SG | -0.43 |
| Hyundai | HiS-M209SF | -0.43 |
| Hyundai | HiS-M212SF | -0.43 |
| Kyocera | KD205GX-LPU | -0.43 |
| Kyocera | KD185GX-LPU | -0.43 |
| Kyocera | KD210GX-LPU | -0.43 |
| Kyocera | KD215GX-LPU | -0.43 |
| Tianwei | TW175(35)D | -0.43 |
| Tianwei | TW180(35)D | -0.43 |
| Tianwei | TW185(35)D | -0.43 |
| Conergy | Conergy P 185M | -0.44 |
| Day4 Energy | Day4 48MC 160 | -0.44 |
| Day4 Energy | Day4 48MC 165 | -0.44 |
| Day4 Energy | Day4 48MC 170 | -0.44 |
| Day4 Energy | Day4 48MC 175 | -0.44 |
| Day4 Energy | Day4 48MC 180 | -0.44 |
| Day4 Energy | Day4 48MC 185 | -0.44 |
| Day4 Energy | Day4 48MC 190 | -0.44 |
| Tianwei | TW210(28)P | -0.44 |
| Tianwei | TW215(28)P | -0.44 |
| Tianwei | TW220(28)P | -0.44 |
| Tianwei | TW225(28)P | -0.44 |
| Tianwei | TW230(28)P | -0.44 |
| Tianwei | TW235(28)P | -0.44 |
| Canadian | CS5A-160M | -0.45 |
| Canadian | CS5A-170M | -0.45 |
| Canadian | CS5A-180M | -0.45 |
| Canadian | CS5P-220M | -0.45 |
| Canadian | CS5P-230M | -0.45 |
| Canadian | CS5P-240M | -0.45 |
| Conergy | Conergy PowerPlus 220P | -0.45 |
| Conergy | Conergy Black 225PA | -0.45 |
| Conergy | Conergy PowerPlus 225P | -0.45 |
| Conergy | Conergy Black 230PA | -0.45 |
| Conergy | Conergy P 230PA | -0.45 |
| Conergy | Conergy P 235PA | -0.45 |
| SCHOTT | POLY 220 | -0.45 |
| SCHOTT | POLY 225 | -0.45 |
| Solarfun | SF190-27-P170 | -0.45 |
| Solarfun | SF190-27-P175 | -0.45 |
| Solarfun | SF190-27-P180 | -0.45 |
| Solarfun | SF190-27-P185 | -0.45 |
| Solarfun | SF190-27-P190 | -0.45 |
| Solarfun | SF220-30-P210 | -0.45 |
| Solarfun | SF220-30-P215 | -0.45 |
| Solarfun | SF190-27-P195 | -0.45 |
| Solarfun | SF220-30-P220 | -0.45 |
| Solarfun | SF190-27-P200 | -0.45 |
| Solarfun | SF220-30-P225 | -0.45 |
| Solarfun | SF190-27-P205 | -0.45 |
| Solarfun | SF220-30-P230 | -0.45 |
| Solarfun | SF190-27-P210 | -0.45 |
| Solarfun | SF220-30-P235 | -0.45 |
| Solarfun | SF220-30-P240 | -0.45 |
| Solarfun | SF220-30-P245 | -0.45 |
| SunPower | SER-228P | -0.45 |
| Trina | TSM-165DA01 | -0.45 |
| Trina | TSM-170DA01 | -0.45 |
| Trina | TSM-220PA05 | -0.45 |
| Trina | TSM-220DA05 | -0.45 |
| Trina | TSM-175DA01 | -0.45 |
| Trina | TSM-180DA01 | -0.45 |
| Trina | TSM-230PA05 | -0.45 |
| Trina | TSM-230DA05 | -0.45 |
| Trina | TSM-185DA01 | -0.45 |
| Trina | TSM-240PA05 | -0.45 |
| Trina | TSM-240DA05 | -0.45 |
| ET Solar | ET-P672255 | -0.46 |
| ET Solar | ET-P654190 | -0.46 |
| ET Solar | ET-P654195 | -0.46 |
| ET Solar | ET-P672260 | -0.46 |
| ET Solar | ET-P660220 | -0.46 |
| ET Solar | ET-P654200 | -0.46 |
| ET Solar | ET-P672265 | -0.46 |
| ET Solar | ET-P660225 | -0.46 |
| ET Solar | ET-P654205 | -0.46 |
| ET Solar | ET-P672270 | -0.46 |
| ET Solar | ET-P660230 | -0.46 |
| ET Solar | ET-P672275 | -0.46 |
| ET Solar | ET-P654210 | -0.46 |
| ET Solar | ET-P672280 | -0.46 |
| ET Solar | ET-P660235 | -0.46 |
| REC | REC215PE-US | -0.46 |
| REC | REC215PE | -0.46 |
| REC | REC220PE-US | -0.46 |
| REC | REC220PE | -0.46 |
| REC | REC225PE-US | -0.46 |
| REC | REC225PE | -0.46 |
| REC | REC230PE-US | -0.46 |
| REC | REC230PE | -0.46 |
| REC | REC235PE-US | -0.46 |
| REC | REC235PE | -0.46 |
| ET Solar | ET-M572165 | -0.47 |
| ET Solar | ET-M572170 | -0.47 |
| ET Solar | ET-M572175 | -0.47 |
| ET Solar | ET-M572180 | -0.47 |
| ET Solar | ET-M572185 | -0.47 |
| Ningbo | MP-150WP | -0.47 |
| Ningbo | MP-155WP | -0.47 |
| Ningbo | MP-160WP | -0.47 |
| Ningbo | MP-165WP | -0.47 |
| Ningbo | MP-170WP | -0.47 |
| Ningbo | MP-175WP | -0.47 |
| Ningbo | MP-180WP | -0.47 |
| Suntech | STP260-24/Vb-1 | -0.47 |
| Suntech | STP200-18/Ub-1 | -0.47 |
| Suntech | STP205-18/Ud | -0.47 |
| Suntech | STP270-24/Vb-1 | -0.47 |
| Suntech | STP270-24/Vd | -0.47 |
| Suntech | STP275-24/Vd | -0.47 |
| Suntech | STP210-18/Ub-1 | -0.47 |
| Suntech | STP210-18/Ud | -0.47 |
| Suntech | STP280-24/Vb-1 | -0.47 |
| Suntech | STP280-24/Vd | -0.47 |
| Solarfun | SF160-24-P165 | -0.48 |
| Solarfun | SF160-24-P170 | -0.48 |
| Solarfun | SF160-24-P175 | -0.48 |
| Suntech | STP175S-24/Ab-1 | -0.48 |
| Suntech | STP180S-24/Ab-1 | -0.48 |
| Suntech | STP185S-24/Ab-1 | -0.48 |
| Sharp | ND-200UC1 | -0.49 |
| Sharp | ND-123UJF | -0.49 |
| Sharp | NE-165UC1 | -0.49 |
| Sharp | ND-167UC1 | -0.49 |
| Sharp | ND-208UC1 | -0.49 |
| Sharp | ND-130UJF | -0.49 |
| Sharp | NE-170UC1 | -0.49 |
| Sharp | ND-176UC1 | -0.49 |
| Sharp | ND-216UC1 | -0.49 |
| Sharp | ND-U216C1 | -0.49 |
| Sharp | ND-198UC1 | -0.49 |
| Sharp | NT-175UC1 | -0.49 |
| Sharp | ND-220UC1 | -0.49 |
| Sharp | NU-U180FC | -0.49 |
| Sharp | ND-224UC1 | -0.49 |
| Sharp | ND-U224C1 | -0.49 |
| Sharp | NU-U208FC | -0.49 |
| Sharp | ND-U230C1 | -0.49 |
| Sharp | NU-U230F3 | -0.49 |
| Sharp | ND-187UC1 | -0.49 |
| Sharp | NU-U235F3 | -0.49 |
| Sharp | NU-U235F1 | -0.49 |
| Sharp | NU-U240F1 | -0.49 |
| BP | BP 3210N | -0.50 |
| BP | BP 3215B | -0.50 |
| BP | BP3220T | -0.50 |
| BP | BP3220N | -0.50 |
| BP | BP3225T | -0.50 |
| BP | BP3225N | -0.50 |
| BP | BP3230T | -0.50 |
| BP | BP3230N | -0.50 |
| BP | BP 4175T | -0.50 |
| BP | BP 4175B | -0.50 |
| BP | BP 4180T | -0.50 |
| REC | REC205AE-US | -0.50 |
| REC | REC210AE-US | -0.50 |
| REC | REC215AE-US | -0.50 |
| REC | REC220AE-US | -0.50 |
| REC | REC225AE-US | -0.50 |
| REC | REC230AE-US | -0.50 |
| Samsung Electronics | LPC235SM-02 | -0.52 |
| Samsung Electronics | LPC238SM-02 | -0.52 |
| Samsung Electronics | LPC241SM-02 | -0.52 |
About Finn PeacockI'm a Chartered Electrical Engineer, Solar and Energy Efficiency nut, dad, and founder of SolarQuotes.com.au. My last "real job" was working for the CSIRO in their renewable energy division.
Golden Solar GS 50E has a Pmax of -.22
Hi Finn
What would be the temperature coefficient of the Bosche made Panels, actually manufactured in Germany.
I am looking at a 5Kw system to be installled in my WA Home on a North & North East facing roof. Using the Sunnyboy 5Kw inverter. Could you also add the Bosche Panels please?
Many thanks & king rgds.
Gordon
Hi Gordon the Bosch are excellent in the heat their temp coeffs vary from 0.33 to 0.46 depending on the model.
If you split a system over 2 roof areas be sure to do this:
http://www.solarquotes.com.au/blog/solar-panels-on-roofs-facing-different-directions-then-you-need-to-do-this/
Unfortunately thats only about 1/10 of the story when it comes to the right panel for the job.
Sure temp co-efficients matter but if the thin film panels take up 3x the space then you can only fit 1/3 the panels.
If you take the CEC advice you should oversize the array in respect to the panels by 20%. the example given uses 2.6KW panels for 2KW inverter.
This accounts for temp derating in typical conditions and hence little or no energy is “lost” but the inverter can work in its “sweet spot” for efficiency.
Unfortunately most systems even with the best components are poorly designed which has more of an impact than the panel temp co-efficients.
A decent bird poo on a panel can knock down output as much as 20% from the whole array, hence we need some perspective here.
Please let me know the temperature coefficient %/c
of Suntech panel model STP190S-24/AD plus
Thank you for your assistance
how about conergy p 180
Hi Grace
It is -0.44
Everyone tells you that solar cells degrade at .45% per DegC above STC, but how do I predict the cell temperature?
I know variables like wind direction, ventilation, etc.. makes it quite compilcated, but does anyone have practical figures? In SA (read Johannnesburg) we have about 5.6 hours sun with very little wind and summer temperatures of 28 to 32 DegC.
Then, is it worth considering forced cooling under hot conditions?
hi, could you please tell me the temp coefficient of ET m 660250 thanks
Hi Darrol:
It is -0.46
Marius, here’s a web page to go to for the calculations of panel temp
http://pveducation.org/pvcdrom/modules/nominal-operating-cell-temperature
And , if you are in the southern hemisphere, it is best for an array on a north facing roof, next best easterly facing and west if no other options – better still ground mount facing north or north-east
National Panasonic has a great product to reduce the effects of power mismatch caused to mono or poly panel arrays from shading, bird poo, leaves etc.
It’s called a Solar Magic Power Optimiser
With thin film panels these shading, dirt and debris problems are not a major factor – n by-pass diodes kicking in or kicking in at different rates
Could you add Solon panels please.
Solon Black XT 295 -0.47
Solon Black XT 290 -0.47
Solon Blue XT 285 -0.45
Solon Black XT 285 -0.47
Solon Blue XT 280 -0.45
Solon Black XT 280 -0.47
Solon Blue XT 275 -0.45
Solon Blue XT 270 -0.45
Solon Black 245 -0.47
Solon Black 240 -0.47
Solon Corvus 240 -0.47
Solon Blue 235 -0.45
Solon Black 235 -0.47
Solon Corvus 235 -0.47
Solon Blue 230 -0.45
Solon Black 230 -0.47
Solon Corvus 230 -0.47
Solon Blue 225 -0.45
Solon Corvus 225 -0.47
Solon Blue 220 -0.45
Silly article! Implies that solar electricity will do worst in sunnier areas. Whilst there are losses due to the heat coefficient these are compensated by the extra sunlight in most cases. Have a look at the desert knowledge solar centre or sunny portal in high heat areas.
Hi Iain,
Thanks for the comment. I certainly don’t mean to imply that solar will do worse in sunnier areas. What I am trying to say (perhaps clumsily!) is that if you have 2 places with the same amount of sunlight, the hotter place will always be worse for solar electricity than the colder place. The ideal place for solar power is a cold desert, or the top of a mountain. This is why the temperature performance of a solar panel is so important in Australia. And why the STC power of a solar panel is tested at an ambient temperature of about 5 degrees Centigrade.
Hi Finn
Whatis the temperature coefficient of Simax. panels used by Sun Trix? Andy is coming to visit us. tomorrow morning at 11am.
Regards
Terry
Hi Terry,
The Simax SM572-190 has a temperature coefficient of -0.39%/DegC according to the data sheet.
Cheers,
Finn
how about sunearth panels
All the 2012 Sun Earth Solar Panels have a temperature coefficient of -0.40 %/DegC which is excellent.
Hi Finn, I live in Mareeba about 50 klms west of Cairns, we have very hot dry days durring summer and most days of 25c during winter. What sort of panels do you think I should be looking for? And what are your thoughts on one of my quotes on a 8.80kW system running through a SunnyBoy 5000TL of $17,990.00 with $7320.00 of rebate?
Hi Nigel,
I think you should go for a brand name panel (Trina, Suntech, QCells, Solarworld etc), because you can generally believe their temperature specs. Look for a panel that is better than -0.5%/DegC. You don’t say what panels you are getting – but if they are good panels, then that seems a good price. I assume you will be running 2x Sunny Boy 5000TLs with 8.8kW of panels?
I’ve been doing some temperature testing of panels, and have been recording temperatures that the panels get to averaging 50degC/day (sunlight hours) and some as high as 85degC. I guess using these numbers you can calculate the percentage loss of the system due to temperature increase.
Why can’t someone make white solar cells???
Hi Angus,
Thanks for the comment. Wow, that is hot! At 85DegC most panels will lose 30% of their power.
Where are you in Australia, and what colour roof are the panels on?
Finn
Could you give any details on performance of “Q” cell panels.
They are generally awesome. Good performers in the heat and well built with German engineering behind them.
Independent test results from California Here: Q-Cells Solar Panel Comparison
Hi Finn
Sorry I am totally new to this, i just got a new house and need to find the best one for our home we live in Brisbane and think which one is the best for us and about the Temperature Coefficient what dos it means it’s better -.2 better or .-.5 better?
Thank you for your time^^
With temperature coefficient smaller number is better (ignoring the -ve sign).
The units are “%_of_power_lost per rise_in_temperature_of_1_Degree_Celsius”.
So only 0.2% of power lost for every increase in temperature of 1DegC makes for a better performing solar panel than one that loses 0.5% of its power for every fish of 1DegC.
I explain it a lot more clearly here:
http://www.solarquotes.com.au/blog/understanding-solar-panel-specifications-part-2-power-tolerance-efficiency/
Hi Finn, I have found your site very informative and to the point.I live in North Qld. I have 2 phase coming into my house and one quote is for 11.2kwET panels with 2×2.5 sma invertors for a price of around $22,000.The other quote is for 4.05kw hyundai panels with a sma invertor,$12,450. My average consumpton is about 26kw p day tarif11 and 8kw tarif 31. My question is, bearing in mind that technology moves forward quite fast, do I spend that amount of money or $12,000 so that if something super dupa comes on the market later I could spend the other $12000
Regards Peter
Could you add:
Suntech STP250S-20/WD
Temperature Coefficient of Pmax -0.45 %/°C
Please could you add the Jinko range of solar panels to your list.
http://www.greenkit.co.uk/ekmps/shops/clairedavies/resources/Other/jkm-195m-72-ebs-sonder-plus-sortierung.pdf
Thank you for your help.