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11.6kw Solar Roof, but only one Inverter?
- Thread starter ericl
- Start date
So I decided to just stop asking Tesla for the extra 3.8. I figure a 1:1 dc/ac ratio is going to decrease due to inefficiencies because the smallest one is 3.8. It just makes me crazy when I see a 8kw array with 7kw inverter in the same area as me generating more kw.
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Why, I have two 11.4K inverters with about 15kw per inverter. I basically never see clipping.
27 Face South, 7 face East Don't know the exact angle but looks to be between 20-30 degrees. Traditional 1960's Floridia house with low pitch roof.
30/23 = ~1.3 DC/AC ratio. I would loved to get mine to around there but unfortunately Tesla does not make an inverter that size.
As of now you are generating close to 3kw/hr but I am at 2.3kw/hr at 8:50 so I think maybe the direction of my panels + location is giving me less overall. Its pretty cloudy here today. That site you shared actually is a great resource, once I hit PTO I am going to look at the data more closely.
It can handle continuous 7.7kw I have seen it occasionally spike to 7.8kw
Clipping is when the production curve plateau. You need a sunny cloudless day to truly see that as cloud edge effect can cause spikes
any update? Do you have a full cloudless sunny day smooth production curve yet? (no spikes?) I have a friend in a similar boat during the ordering process. trying to see how much clipping lost for a similar system
Lack of PTO means my production just stops as a certain point. So my data is not great. I am at peace of mind knowing my setup will generate the same as year 1 as year 10 and year 20 with the oversize even if there is clipping.
Also I have yet to have a smooth curve because its never not cloudy here haha. I definitely do see some plateauing at 7.6 as it hits that pretty easily at noon on a sunny day.
With only 12 days of data I am approximately.
Rainy days = ~30kw
Cloudy days = ~40kw
Semi-Cloudy = ~50kw
Highest I have gotten is 55kw.
Lowest I have gotten is 29kw.
Again data is kinda screwed up because of PTO and I am having other renovations being done. I deplete my powerwall to 10% at night and then in the morning set my AC to always on and sometimes my powerwall still hits 100% before the end of day. I work at home too.
Live in FL also. My solar system is 9.52 kw. I have 3 powerwalls including one powerwall+ Have my system for about a month. NEVER get over 7.7 kw. Don't think we are getting the correct info! By the way was your project advisor Joel?
Eric = Powerwall Manager.
Sean = Roofing Manager.
I'm guessing you have one 7.6 too? I just cap at 7.7 and plateau for 3 hours. Inverter also has to restart for about 10 min always a little past 1pm.
@OY1836 yeah I agree you are at 1.25 dc/ac ratio so you're fine. If you add another inverter you will likely lose production from times outside of peak.
Are all your panels facing due South with no shading? A 7.7 kW peak for a 9.5kW system is not bad. Also, the peak time of year for solar production is June 21, the summer solstice. Before or after that it then it will likely be less.
SageBrush
REJECT Fascism
That is very much a YMMV. Probably true for panels lying close to flat. My peaks are spring and autumn
I'm guessing a lot of that is due to ambient and panel temperatures being cooler during the day for those seasons, thus much less temperature derating, esp in New Mexico.
SageBrush
REJECT Fascism
That is part of it; the other part is related to panel inclination. Flat roofs enjoy the sun at 75 degrees during the solar window in the summer but generation drops in the shoulder seasons when the sun is at ~ 50 degrees during the solar window, and of course generation collapses in the winter when the sun is at 30 degrees. A panel angle closer to latitude in the sun belt is best positioned for shoulder seasons.
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For ground mount solar at a fixed angle, the optimal (maximum energy production) inclination angle will be below the optimal angle on the solstice, as the rest of the year the sun will be lower in the sky. And the optimal angle on the solstice itself will be lower than the noon elevation angle of the sun, as the rest of the day the sun will be lower in the sky.
For roof mount solar, panel inclination is typically dictated by roof slope, so it's a toss up on what day the optimal panel angle for that day will most closely match the roof slope. Although for low slope roofs in the mid to upper latitudes, the panel inclination angle will likely be quite a bit lower than optimal, so then the solstice would be closest to optimal.
Cheers, Wayne
What happened in the end here? Is there really an overdrive that allows you to take in your full 11.6kw? I"m in the same boat, just installed a 12kw solar array, have 1 powerwallplus, which spec sheet says supports 7.6kw, and it is written on top of the system. My system hasn't been officially turned on but i did run it for one day to charge batteries. Solar power clipped at 7.6kW for 4 hours and this is end of september. Unless there is a hidden overdrive that is enabled, it doesn't seem like the system supports > 7.6kw.. Given i'm not approved to operate i don't know if the system is in a state that limits any potential overdrive.. Given the graph i have, i'm guessing right now i'm missing ~10-15kwH/day, and probably 20-30kwh/day in the summer if this is correct. What was the final outcome after your system was approved
No overdrive.... They would need to increase your wiring awg size and breaker size to handle the higher output, if they never did that during install....
Where are you located? All your panels face the same direction and which direction?
