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The lack of agreement between your PVOutput.org page and your SolarEdge page is interesting. PVOutput shows 4153 W at 13:00 on 3/3, while the SolarEdge public portal shows 4032 W. Any idea why that is? There is a consistent 3% disagreement across all the data that I've just checked.
Assuming the inflated values are correct, I ran a simulation in SAM and scaled the output to match the clear day peak power this time of year to what your system is actually reporting. When production is higher in the summer, most of that extra generation is in the width of the bell curve, not the height of the peak. It would not be surprising if your peak power in June is the same or slightly less than your peak power in March, around 4.4-4.5 kW based on your PVOutput data, because June tends to be warmer. By August, the peak height is even more likely to be lower.
The degree to which scaling was required suggests the 3% inflation is not real, but I am clearly not able to say for sure what is accurate. Even with the inflated output, the difference between clipped and unclipped power annually came out to 136 kWh (<1.5% of annual production), or $67 if all of that occurs during TOU peak... which is unlikely to be true for very many years as SDG&E is proposing to shift the peak times to later in the day when output would have dropped below the 4 kW clipping level.
If the SolarEdge portal values are correct, the clipped energy in this simulation drops to 79 kWh annually (<1% of annual production), or $38. There is reason to doubt that even the SolarEdge portal calibration is correct, so without a revenue grade meter attached on the inverter, it is hard to say exactly what is being produced.
Also keep in mind that the panels will degrade over time... the warranty allows 2% in the first year and 0.7% after that, so you may figure that after at most 5 years, and probably fewer, whatever clipping you would have been seeing now will be gone anyway. 5*38 = $190, which means if the M250's were more than $200 less than the SolarEdge system, either one would be worth the same (all other things being equal, which is probably not true). If the 3% higher vales are correct, the total value clipped may max out at more like $300-$400, but probably less.
None of this is intended to say that I think designing a system with clipping is a good thing. All I'm saying is that if avoiding clipping is going to be a design decision, the cost-benefit of that decision can be estimated. I believe that spending several hundred $$ to avoid clipping is rarely supported when the panels are only 1.2X the inverter capacity, as they are with 300 W on a 250 W microinverter. If there is no difference in cost, then sure, avoid clipping if you can. If you buy into the idea that operating the inverter at its rating for an hour or two a day for part of the year will shorten its life, and spending more money upfront on a larger inverter will prolong the life of the system, I won't argue with that either, but only point out that I have found no evidence that it is true.
Please do not to take this as an argument in favor of microinverters over SolarEdge. They each have their place, but in general, I would avoid microinverters for reasons that have nothing to do with clipping.
In the grand scheme of things, a few hundred dollars either way is pretty insignificant, so as long as a system is not grossly mis-sized, my interest and arguments are more weighted towards the decision making process, not so much the outcome. The outcomes are all essentially the same.
None of this is intended to suggest I can see the future. However, I continue to believe that modeling expected outcomes, informed by current data, is a reasonable way to make decisions about how I would choose to spend my money, or advise others on how to spend theirs (when asked).
Assuming the inflated values are correct, I ran a simulation in SAM and scaled the output to match the clear day peak power this time of year to what your system is actually reporting. When production is higher in the summer, most of that extra generation is in the width of the bell curve, not the height of the peak. It would not be surprising if your peak power in June is the same or slightly less than your peak power in March, around 4.4-4.5 kW based on your PVOutput data, because June tends to be warmer. By August, the peak height is even more likely to be lower.
The degree to which scaling was required suggests the 3% inflation is not real, but I am clearly not able to say for sure what is accurate. Even with the inflated output, the difference between clipped and unclipped power annually came out to 136 kWh (<1.5% of annual production), or $67 if all of that occurs during TOU peak... which is unlikely to be true for very many years as SDG&E is proposing to shift the peak times to later in the day when output would have dropped below the 4 kW clipping level.
If the SolarEdge portal values are correct, the clipped energy in this simulation drops to 79 kWh annually (<1% of annual production), or $38. There is reason to doubt that even the SolarEdge portal calibration is correct, so without a revenue grade meter attached on the inverter, it is hard to say exactly what is being produced.
Also keep in mind that the panels will degrade over time... the warranty allows 2% in the first year and 0.7% after that, so you may figure that after at most 5 years, and probably fewer, whatever clipping you would have been seeing now will be gone anyway. 5*38 = $190, which means if the M250's were more than $200 less than the SolarEdge system, either one would be worth the same (all other things being equal, which is probably not true). If the 3% higher vales are correct, the total value clipped may max out at more like $300-$400, but probably less.
None of this is intended to say that I think designing a system with clipping is a good thing. All I'm saying is that if avoiding clipping is going to be a design decision, the cost-benefit of that decision can be estimated. I believe that spending several hundred $$ to avoid clipping is rarely supported when the panels are only 1.2X the inverter capacity, as they are with 300 W on a 250 W microinverter. If there is no difference in cost, then sure, avoid clipping if you can. If you buy into the idea that operating the inverter at its rating for an hour or two a day for part of the year will shorten its life, and spending more money upfront on a larger inverter will prolong the life of the system, I won't argue with that either, but only point out that I have found no evidence that it is true.
Please do not to take this as an argument in favor of microinverters over SolarEdge. They each have their place, but in general, I would avoid microinverters for reasons that have nothing to do with clipping.
In the grand scheme of things, a few hundred dollars either way is pretty insignificant, so as long as a system is not grossly mis-sized, my interest and arguments are more weighted towards the decision making process, not so much the outcome. The outcomes are all essentially the same.
None of this is intended to suggest I can see the future. However, I continue to believe that modeling expected outcomes, informed by current data, is a reasonable way to make decisions about how I would choose to spend my money, or advise others on how to spend theirs (when asked).
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