Researchers from the Germany Fraunhofer Institute for Solar Energy Systems ISE have found that a latest trend in solar panel expenses is often less than the evaluation of the name tags. It may not be much, but that’s not the point.
The capacities of the solar panel name signs are often accompanied by a “performance tolerance”, which indicates that the area that the actual output of a PV module can vary from its nominal capacity. A few years ago, this was usually a “±” number that was expressed in watts or as a percentage. For example, a 250-watt solar panel may have determined a performance compatibility of ± 5%, which means that the output of the panel could be 237 W to 262.5 W. It is quite a reach.
The industry generally has a positive performance tolerance, especially among brands, as better quality, which means that if you buy a 440 watt solar panel, you would spend the minimum under standard test conditions. Or maybe a little more. It is a sales argument.
What Fraunhofer found
Researchers of Callab PV modules at Fraunhofer ISE have tested 70,000 solar modules since 2012. After this data had been filtered in accordance with the evaluation criteria, the analysis of 1,034 performance measurements associated with monocrystalline solar panels resulted in a new trend in recent years.
From 2012 to 2016, the measurement deviations were on average less than one percent and positive deviations were also measured. In 2016, the deviation was 0.6 percent and in view of a period in which ± power tolerance was usually specified and clearly stated on data sheets, it was a non-output. But since then it has been a different story; especially between 2020 and 2023.
“For 2023, this culminated in a negative deviation between the manufacturer’s specification and our review of around 1.3 percent,” said Daniel Phillip from Fraunhofer ISE. “A positive deviation has hardly ever been observed.”
The researchers recorded a slight reversal of the trends in 2024, but still negative deviations of 1.2 percent on average, said Mr. Phillip. The easy improvement may be due to the fact that manufacturers recognize that they were over-optimistic-or rumble that the template has expired.
Which manufacturers are involved?
A total of 15 manufacturers were included in the evaluation. Fraunhofer doesn’t say who they were. However, it offers a number of potential suspect as the only manufacturer among the top 10 (assumed: for programs) in the analysis in the respective review of the review. While this contains all the big names in panel production, this does not mean that all of these companies were “excessively optimistic”.
What are a few watts between friends?
The discrepancies may not sound a lot and are not really so often related to the solar systems in oversized systems in Australia. Here the capacity of the solar inverter is less than the overall capacity of the panel to:
- Maximize the sun discount.
- In some cases, bypassing inverter restrictions.
- Improve the average inverter work efficiency.
- Take into account different system efficiency and the wide range of conditions under which the panels will work.
However, it is not a good look for manufacturers if their data sheets cannot be familiar.
On this point, however, Kim from 2023 SQ showed another trick used – “measurement tolerance”; Usually in the small print on a data sheet. This is essentially a permissible area of variation that is permitted in top performance when measuring watt watts.
Let’s look at an example of a 440 -W panel again with a clearly specified positive performance compatibility of 0 ~+5W. The data sheet I checked had a “measurement tolerance” (in tiny pressure) of ± 3%; This is apparently a common figure.
This means that this 440W panel could actually only be 426.8 W. On the other hand, it could be up to 453.2W. Multiply this to the number of solar collectors and in the long term to lead a considerable amount of potential production in both cases. But here, too, the system comes into play and some panels in a system can be a bit over and others a bit under; Balancing.
However, if you have been sold a 10 kW system and there is no accompanying documentation that indicate that it may not be very 10 kW, this should be installed.
As KIM suggested, Australian solar buyers or owners should not be slept through the guaranteed protection of the guarantee, but for the same reason it should consider a problem with the system system. It also shows the importance of independent tests by third -party providers by organizations such as Fraunhofer ISE. Regarding topics and reminds that the manufacturers are observed.
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