Small & Powerful Modules for Residential PV

As advanced solar module technologies have matured over time and with the flexibility that they offer, the industry has tried its hand at combining multiple technologies in a single product – and has found commercial success. Such fusion products available in the market today bring the best performance and cost propositions to the table. With the technology bifurcation for commercial PV panels becoming obsolete, application is finding its place at the core of module design.
When it comes to residential, the segment is often regarded as premium. The PV systems here are rather small in the range of kilowatts and are typically added on rooftops of households. Since the roof space is also limited, high efficiency modules that deliver high power per unit area are typically preferred, in particular as storage allows large solar self-consumption levels and EVs require more power. In terms of dimensions, smaller and lighter modules are preferred to facilitate ease of handling and installation. There are also limits in certain countries for the maximum size of rooftop modules.
When it comes to technology preferences, all high efficiency cell and module technologies are of interest, while bifacial, especially the glass-glass configuration, has little significance here for two reasons. First, in a residential rooftop installation, PV panels are typically attached to the top of a roof where the chances of the rear side receiving sunlight are slim. Plus, glass-glass modules are relatively heavy, making them a no go for residential systems. However, this may not be a concern in areas with flat-roof households or carports. Modules with superior aesthetics are also in demand for residential applications.
A total of 16 modules from 6 different manufacturers make our list for this segment in our Advanced Solar Module Technologies Report 2021. Owing to the fact that high efficiency cell architecture based products are a nice fit for this segment, 7 products are based on the n-type cell architecture. The split is as follows: 4 back contact modules of which 3 are from Maxeon and one from Futurasun, and 3 HJT panels comprised of one from Risen and 2 from REC. Futurasun's product additionally incorporates a half-cell layout. As for advanced module concepts, in addition to the above mentioned back-contact products, Maxeon is also promoting a shingling based module. While bifacial is not a good fit, one such model from Risen based on HJT with its natural very high bifaciality is still promoted for residential applications. Out of these 16 products, 12 models have efficiencies of above 21% and none of the remaining below 20%. The most efficient module of this overview, the IBC panel from Maxeon with 22.7%, is also featured in this segment.
As larger modules are not preferred by installers of residential systems, the number of cells and their size are what matter the most. One exception would be Maxeon's 72-cell equivalent panel based on the M4 format. Even with its somewhat large dimensions of 2 m², this 415 W AC module with a built-in microinverter and its uniform appearance justifies its promotion to the residential specialty. Among the remaining, it's again Maxeon that is offering a product with a top power rating of 400 W. With 11 models, the 60-cell based configuration appears to be the mainstream format against 5 products with 66 and 54-cell equivalents in the list.
Within the n-type segment, the largest wafer size is M4, while Maxeon is still offering panels based on the smaller 125 mm wafers. M6 and G1 are the main formats seen among monocrystalline panels. Last but not the least, pleasing aesthetics are a huge plus in residential applications. A simple way to achieve this is by employing a black backsheet that significantly improves the module's appearance. A total of 5 such panels are featured in the current listing from Maxeon, REC and Suntech. This also explains why there is a double listing of products under these companies, although they belong to the same technology streams. However, having a black rear cover eliminates the coupling gains from the cell spacing that often leads to lower power rating. Maxeon's IBC based product has the highest loss of 25 W compared to the white background variant, while the products from REC and Suntech lose one wattage class of 5 W with a black backsheet. On the other hand, Suntech apparently managed to have no such losses with its Ultra V mini series, with both the variants rated at 410 W.
The text is an excerpt from the TaiyangNews Advanced Solar Module Technologies 2021 report. For more details on advanced solar modules and their applications in various segments, please download and read TaiyangNews' report on Advanced Solar Module Technologies 2021, here
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