I previously described my system in my "How much variation in panel output is normal?" post. Basically, it consists of 24 panels (13 Silevo 305w and 11 Panasonic 325w) with SE6000A inverter and p400 optimizers. I have observed a fair amount of variation between the panels within each brand. One reason why I was interested in the normal amount of variation was because it appeared that the Silevo panels were underperforming compared to the Panasonic. Without radiation data, it appeared to be impossible to know whether my Silevo panels were performing below their warranty level of performance. I recently learned of a site called Solcast which offers estimates of solar radiation as well as power predictions.
They "use images of clouds taken by weather satellites and a series of modelling steps to produce estimates of the available solar radiation at any given location. These values are updated by Solcast with each new satellite scan every 10 to 15 minutes. Solcast continually calibrates and improves estimated actuals against surface measurements."
They offer an API, which is free to hobbyists and solar enthusiasts, where one can enter your location, array capacity (DC kW), tilt, azimuth and longitude and latitude and it will generate a table of estimated power from your array. You can compare their estimates with your outputs from your inverter to estimate your system's degredation and add &loss_factor= to your API request to refine your estimates. Alternately, I could divide my reported energy by my expected energy output to determine and compare the relative degredations of my 2 brands of panels.
Since I have 2 types of panels, I would need to perform the calculations for each sets of panel. My SE monitoring site provides production data for each panel so I can calculate the reported production from each panel (of known brand) per day and compare it to the Solcast estimates.
Can I use this data to evaluate the performance of my Silevo panels?
If they appear to be performing below the warrantied level, will Tesla (who bought SolarCity who bought Silevo) honor a warranty claim for Silevo panels?
I look forward to your expert feed back and comments.
They "use images of clouds taken by weather satellites and a series of modelling steps to produce estimates of the available solar radiation at any given location. These values are updated by Solcast with each new satellite scan every 10 to 15 minutes. Solcast continually calibrates and improves estimated actuals against surface measurements."
They offer an API, which is free to hobbyists and solar enthusiasts, where one can enter your location, array capacity (DC kW), tilt, azimuth and longitude and latitude and it will generate a table of estimated power from your array. You can compare their estimates with your outputs from your inverter to estimate your system's degredation and add &loss_factor= to your API request to refine your estimates. Alternately, I could divide my reported energy by my expected energy output to determine and compare the relative degredations of my 2 brands of panels.
Since I have 2 types of panels, I would need to perform the calculations for each sets of panel. My SE monitoring site provides production data for each panel so I can calculate the reported production from each panel (of known brand) per day and compare it to the Solcast estimates.
Can I use this data to evaluate the performance of my Silevo panels?
If they appear to be performing below the warrantied level, will Tesla (who bought SolarCity who bought Silevo) honor a warranty claim for Silevo panels?
I look forward to your expert feed back and comments.
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