Powerful Modules For Utility Scale Solar

Utility is by far the largest branch of PV applications with large-scale installations reaching up to GW-scale. This section of our TaiyangNews Solar Module Innovations 2022 report discusses modules promoted for ground-mount installations. For utility-scale projects, a low module price is the main requirement. The $/W metric has been the key criterion for module selection in the past. However, the segment is slowly but surely adopting the LCOE based $/kWh metric. So while price will always remain in focus, higher module power is what matters overall in terms of technicalities. There is an industry-wide belief that high module power helps keep the EPC and BOS costs low. But high power alone does not suffice. The benefits of BOS cost reduction can be realized when the voltage of the module is maintained constant while increasing the current of the module so that the string count can be kept in check. In turn, this helps reduce the costs associated with electrical components. The benefits of high power modules are even more pronounced when using string inverters and trackers. Size is another important characteristic of the module when using trackers. Maximum utilization of tracker support area, determined by the module size, is an important aspect that should be taken into account. Bifacial technology, with its ability to increase the power yield, is a technology that is increasingly preferred, and bringing trackers into the mix is turning out to be even more beneficial.

Our listing of modules for utility-scale solar consists of 40 products from 11 suppliers, meeting the aforementioned qualification criterion. It can be observed from the listing that the idea of employing larger wafers for increasing peak power is one that is well received. Both G12 and M10, the two commercially available larger formats, represent the major chunk — 11 and 17, respectively, for a total of 28 products out of 40. This change is quite significant compared to our previous report , which just listed 4 products. Still, this is not a complete representation of the module products for utility-scale PV systems as companies are choosing to broaden the application spectrum by labeling them ‘utility and C&I’. It is also evident that modules based on smaller wafer sizes are silently fading away, with just 7 products based on M6 and only 4 based on G1 format.

Larger wafer sizes dominating: In the listing of utility-only modules in our TaiyangNews Solar Module Innovations 2022 report, 28 out of 40 are based on either G12 or M10 format — evidence that modules based on larger wafer sizes are being increasingly promoted for utility-scale applications. (Source: TaiyangNews)

With regards to the technology, half cell and MBB are the minimum qualification criterion anyway; but bifacial is one technology that is increasingly preferred in utility applications. As can be seen from the listing, 15 out of 40 products are bifacial, meaning either the modules are exclusively offered as bifacial or the same product is available in both monofacial and bifacial variants with the same power rating. Bifacial variants of most products are also available but usually with 5 W lower power. Those products, however, do not make it to our list since only the most powerful module of a series gets featured (see The Power Of “Module Power”).

As for the number of cells, it completely depends on the wafer size. For G12, 132 and 120 half cells are the two main cell counts. The M10 format comes in several configurations such as 156, 144, 132 and 108 half cells.

Cell counts of 144 and 120 are common for M6, while LONGi is the only company offering a PERC module in the 132-cell layout. G1 based products from only two companies — Talesun and Hyundai — qualify for this utility listing. The shingled module from TW Solar appears somewhat special here with a cell count of 408, with each of 68 of the G12 cells is sliced into 6 pieces. In reality, it is a 132-cell equivalent module based on the G12 cell size.

While modules based on high-efficiency cell architectures such as TOPCon were not primarily targeted for utility applications, the trend seems to be changing. We have 8 TOPCon modules from Jolywood, Suntech and Megasol. And Jolywood is leading not just within the TOPCon segment, but the entire ‘utility-only’ listing. The most powerful module in this report, the 700 W 132-cell TOPCon panel based on the 210 mm wafer format from Jolywood, is promoted for power plant type installations. Then, Suntech’s TOPCon module based on M10 with 156 half-cells and a rated power of 620 W is also labeled for utility applications.

Among PERC products, GCL is offering the most powerful and efficient product; a G12 module in a 132 half-cell configuration with a rated power of 675 W and 21.7% efficiency. Following the same configuration, the next powerful modules at 670 W come from four companies — CSI, Suntech, Talesun and Trina. Except Trina, all the above companies also offer G12 based 120-cell modules. Within the M10 format, it is Suntech’s 590 W module that tops the power listing. As we emphasized in our previous report, multicrystalline is on its way out. While the previous edition included two multicrystalline products, they are completely absent from this year’s utility-only section.

The Text is an excerpt from TaiyangNews’ recent solar module innovations report 2022, which can be downloaded for free here.