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Tesla Plan Set to PVWatts
- Thread starter Grayson73
- Start date
By default, PVWatts will assume all south-facing panels at 20deg roof pitch, which is close to optimal in the northern hemisphere. From your Tesla plans, you can get the azimuth, pitch, and size for each array (generally each different part of your roof, they will be labeled MP1, MP2, etc). You'll have to configure each array separately in PVWatts and then add up all the production values.
If you have any shading issues, you can increase the default %14 loss to adjust for that (that requires some experimentation based on your actual values). If you have snow-covered panels in the winter, you can adjust loss by month. DC-to-AC ratio usually plays a small part and can be left as default.
All that said, your production values are too small compared to the estimate to be explained by PVWatts parameters. How do other months compare? How does the annual estimate compare to your Tesla annual estimate?
If you have any shading issues, you can increase the default %14 loss to adjust for that (that requires some experimentation based on your actual values). If you have snow-covered panels in the winter, you can adjust loss by month. DC-to-AC ratio usually plays a small part and can be left as default.
All that said, your production values are too small compared to the estimate to be explained by PVWatts parameters. How do other months compare? How does the annual estimate compare to your Tesla annual estimate?
Thanks, I'll check the plan set and try to figure it out.
January 2024 is my first full month so I don't have any additional data yet.
If this is a new system and you don't permission to export yet, that can affect production as well -- solar production will be reduced to match home usage if there aren't sufficient batteries to soak up the excess.
Thanks. I have 2 Powerwall 3s and they haven't been full so no wasted energy.
Tesla estimated that I would get 12,657 kWh with my 14.175 kW system. I put in the Azi and Pitch for my 4 arrays and put in 29.5% system loss (I must have a lot of shading!) and it totaled 12,660 kWh. Now it is accurate since I'm generating 20 kWh on sunny days and January should average 18. I was still way down for January (258 kWh vs. 568 kWh), but they were covered in snow for many days and we've had a lot of cloudy days as well. I probably won't reach Tesla's estimates unless my averages start increasing. Thanks for your help!
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Matt-FL
Member
Matt-FL
Member
I have PW2s, 2 7.6Kw inverters (pre-PW+) and a Gateway v2. I guess PW3s are more complicated with their inverters.
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