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I have a Solis 10 kW inverter, model S5-GR3P10K-AU (https://www.solisinverters.au/produc...S5-GR3P(5-20)K). Total power of the panels is 12.32 kW. According to the inverter's datasheet (https://www.solisinverters.au/upload...2,3_202411.pdf), it has 98.5% Max Efficiency and 97.9% EU Efficiency. Using the smaller of the two, the inverter should be peaking at 9.79 kW. Presuming in real life you never get the promised numbers, I'd expect 9.6 or at least 9.5. What I actually get is ~9.3 kW. Is this expected, or is there a setting somewhere that further limits the inverter output from what it can actually do?
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Welcome to the forum. Run a program like this one to see what your average output should be based on location, tilt, etc, etc etc.
PVWatts Calculator
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Thanks, but that program asks a million questions that I do not know answers to. I just want to know what's limiting my system output. Looking at the graph I do not think it's the panels because then the graph would have a curved peak, while mine is flat. It has to be the inverter then, but is it hard-set or configured somewhere?Last edited by AndyS; Yesterday, 09:39 AM.Comment
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What graph ?
Without more information it's impossible to give even a dart throw guess at an answer to your question.
For starters, you have 12.32 STC kW of potential output. About the best that's possible from a very clean, well-designed array under ideal steady-state conditions under a clear sky with the sun perpendicular to the array will be about 85% or so +/- a couple percent of the STC designed array output, or 12.32 * 0.85 = ~ 10.47 kW.
If you don't clean the array regularly, knock another 5-10 % off that.
If the sun is off perpendicular, reduce the output even more.
The instantaneous array output varies constantly with the solar position, season and weather.
The actual output will always be less than the approx. 85 % number, often substantially less. That's normal.
As for PVWatts, read all the help screens before you do any input.
You may be a tecnophobe, but that model is just about dummy proof.
Reading ALL help the screens will explain further what I wrote above and lots more.
My guess is an hour or so spent with the model, its help screens and some input from you will help you self supply answers to your questions.
For further reading, download a copy fo " Solar Power Your Home for Dummies". It's a free PDF on the net easily available with some rooting around.
Welcome to the forum of few(er) illusionsComment
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Seems pretty normal. You rarely if ever get enough sunlight at the perfect angle to all solar panels at the same time in order to get the max power output.Comment
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Thank you everyone who replied so far. In my comments I've been referring to a graph that I thought I had posted in the original question but someone has pointed out to me that there's no graph showing. To me it was always showing but now I refreshed the browser and it's gone, not sure what happened there. I'm posting it again here, that's what my output looks like on a good sunny day in the middle of summer. As you can see its top is chopped off by a straight line at ~9.3 kW, I don't think the panels can behave that way. The graph would be smooth, probably something close to what I drew in blue. That's why I'm presuming it's the inverter that's limiting the output and trying to find out if it's hard set or can be configured.
image.pngLast edited by AndyS; Yesterday, 08:16 PM.Comment
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It is called clipping and the inverter deos that to protect itself. I can't imagine there would be a user setting to allow you to exceed that output. Maybe if the inverter was just turned on moments before and located in a very cold room might you see slightly better output. Remember, the efficiency numbers you see advertized in the literature are set by marketing people who will stretch the truth to the very limit to make their product seem like the best one to buy. I see no reason to lose any sleep over what you are seeing.Dave W. Gilbert AZ
6.63kW grid-tie ownerComment
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Yeah it's inverter clipping. Quite normal. Don't get hung up on the 98.5% max efficiency. That's only achievable under ideal (typically in a lab) conditions including temperature for a short time since the inverter itself will heat up quickly from generating power which in turn will cause reduction in power generation.Comment
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azdave, solardreamer, thank you for explaining about the inverter clipping. I thought it was the inverter, and I do understand that I cannot be expecting the 97-98% efficiency advertised in the brochure. I guess my last question would be whether I can configure the inverter to output more. Below are two power-related settings I found in the configuration.
The first one keeps changing in the range of 106-109% every time I click "Read" next to it. So seems it's already set to the allowed 110% maximum but for some reason the actual running value the inverter is using is always slightly less.
The second one is 10000 W which is the exact inverter's rated output. Can I increase it, will it make a difference? Or should I not touch it because it can cause a malfunction?
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It's probably temperature limited regardless of the max power output setting. The inverter will reduce power if the temperature is too high to prevent burning itself up. As a test, I have gotten higher inverter power output by having a big cooling fan blow on an inverter with the cover open.Comment
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I myself would not push the settings any further just to gain a fraction more output. If you did manage to get that an extra little boost, how do you know you aren't possibly shaving a few years off of the service life of the inverter by running it beyond the factory settings? If you have an inverter failure, and try to file a warranty claim, will the manufacturer be able to detect that you changed those settings and thus void any coverage?Dave W. Gilbert AZ
6.63kW grid-tie ownerComment
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