- Having limited space on rooftop high efficiency and light weight modules are preferred for residential solar rooftop installations
- Since aesthetics matter a lot here, all black modules with black backsheet and black frame are quite famous in this segment
- The residential section of the TaiyangNews report listed 41 products from 17 module manufactures covering various advanced module technologies
The residential segment is heating up in several markets around the globe, which is also reflected in our report.
The requisites of this application are totally different compared to those of utility-scale modules. The systems are rather small, range in kilowatts and are typically installed on household rooftops. Since the roof space is also limited, high efficiency modules that deliver high power per unit area are typically preferred, in particular as the provision to store power allows for large solar self-consumption levels for applications such as charging EVs. That’s also the reason why residential is regarded as a premium segment. In terms of dimensions, smaller and lighter modules are preferred to facilitate ease of handling and installation. There are also size limits in certain countries for rooftop modules.
With respect 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. Modules with superior aesthetics are also in demand for residential applications. A very popular design in this space is the all-black module with a black backsheet and frame.
While the previous edition of our report featured a total of 16 modules from 6 different manufacturers, the current listing for this segment consists of 41 products from 17 manufacturers. High efficiency cell architecture based products dominate this segment, owing to the fact that they are a nice fit here. A total of 23 products are based on the high efficiency cell technologies including 14 IBC, 5 HJT and 4 TOPCon panels. Back-contact modules are supplied by Maxeon, LG, SPIC and FuturaSun, while well-known HJT followers Meyer Burger, REC and Risen are also offering modules based on this technology. JinkoSolar, LG, Suntech and Megasol are the notable suppliers of TOPCon products for residential-only applications.
While half-cell is a pre-requisite for our listing, we have also included the full-cell layout for modules based on sophisticated back contact technology. While LG offers its IBC modules only in the full-cell layout, Maxeon, SPIC and FuturaSun have also adapted the technology to half-cell. Shingling, providing superior aesthetics and higher efficiency, is also an interesting module technology for residential applications. Maxeon, with strong IP on the technology, is obviously the key supplier of such modules, while TW Solar is also promoting shingling based products. While bifacial is not a good fit here, 3 products — one from Risen based on HJT with its natural very high bifaciality and one TOPCon module each from Risen and Suntech — are still promoted for residential applications. Out of these 43 products, 34 models have efficiencies of above 21% and the remaining 11 have efficiencies of 20% or above. The most efficient module of this overview, the IBC panel from Maxeon with 22.8% efficiency, is also featured in this segment.
Aesthetics are important: while high efficiency is very important in the residential segment, some prefer aesthetics even at the cost of performance. (Source: TaiyangNews)
Given that installers don’t prefer larger modules, the number of cells and their size are what matter the most. As for wafer sizes, ‘pure’ residential modules based on larger wafers have not found many takers, at least among the commercially available products by the time we prepared the report. One exception would be Suntech’s 144-cell panel based on the M10 format that does not justify being promoted for residential applications due to its larger size. However, the PERC module of the company is also based on M10, but with a lower count of 108 keeping the size in context, an approach also followed by GCL. This approach of using a smaller number of cells and cutting them in half or 1/3rd is expected to become more common in the residential segment as PV manufacturers increasingly adopt larger wafers. Except for these 3 products, the remaining modules listed here are based on wafer sizes M6 or lower, while Maxeon is the only module maker that is still promoting 5-inch wafer based products (see: The Power Of “Module Power”).
As for cell count, 60, 66 and their equivalent half-cell configurations are the mainstream, as there are three companies other than Suntech promoting a total of 4 products based on a 72 or 144 cell layout.
Apart from size, 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 8 such panels are featured in the current listing from Maxeon, REC, FuturaSun, Meyer Burger, LG, TW Solar and Hanwha Q-CELLS. 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 FuturaSun and REC lose 10 W and 5 W, respectively. A few companies, especially those focusing on the US rooftops market such as Maxeon and LG, are also offering AC modules, which are integrated with a micro-inverter. The specialty of the modules from Meyer Burger and REC is that they employ an innovative SWCT interconnection technique that suits HJT very well. All modules from TW Solar are interconnected using the shingling method (see: Powerful Modules For Utility Scale).
The Text is an excerpt from TaiyangNews’ recent solar module innovations report 2022, which can be downloaded for free here.