With PV module manufacturers having aggressively cut costs to compete in the ongoing price war, the negative consequences are starting to filter through. Recent failure rates in testing point to the worrying consequences of cost cutting taken too far. Cost savings of a few tenths of a cent per watt could impact solar module reliability, leading to dramatically higher failure rates, and it is more important than ever for buyers to be aware of the specific bill of materials being used in their modules.
It is no secret that PV manufacturers have been having a torrid time over the past two years. As new polysilicon capacity came online through 2023, relieving the previous bottleneck in the supply chain, production accelerated far ahead of demand, sending prices through the supply chain crashing. As manufacturers first looked to maintain profitability, and later to limit losses, many set about aggressively cutting costs. In some cases, manufacturers were able to innovate, finding new solutions to reduce cost without impacting quality. In others, some simply cut cost without due care and attention to the consequences.
For at least 18 months, we have been warning subscribers to CRU and Kiwa PVEL’s co-authored Solar Technology and Cost Service of the risk to module reliability from this aggressive cost-cutting. Last summer, we highlighted a particular risk from frames, flagging our discussions with frame manufacturers. They had expressed a concern that in some cases module manufacturers were pushing too far with slimming down wall thicknesses and were compromising on quality.
Unfortunately, the impact of this now seems to be coming through in pv module reliability testing results. Over the past year, Kiwa PVEL has seen a hugely concerning 20% failure rate in its mechanical stress sequence (MSS) testing – up from only around 6% a year earlier, and partly attributable to this stripping down of frame designs.
When comparing frame drawings for an exampleold frame that passed the MSS testing and a newer frame that broke in the MSS test, the old frame weighed ~3.2 kg for a 2278* 1134 mm module, while the new frame design was ~2.9 kg for the same module – a reduction in aluminium of ~9%. Based on quotes CRU has received from manufacturers, we believe some frames have been stripped down even more than this. Quotes from several frame manufacturers transitioned from ~3.2 kg for a module of this size in late 2023 to ~2.6 kg by the end of 2024, implying that some module buyers could be exposed to even greater risk than this particular example.
So how much would it cost to put this right? Based on recent aluminium prices in China, and accounting for the frame processing costs, the ~0.3 kg reduction in weight implied by the frame drawings would correspond to ~0.15 ¢/W for an average TOPCon module. For the more aggressive slimming-down implied by CRU’s data, the cost to go back to the old frame design would be closer to 0.3 ¢/W (though both these figures would typically be higher for frames sourced outside of China). Module manufacturers and module buyers also have the option of the increasing range of alternative frame materials on the market, including steel and composite options (though these have not yet been thoroughly tested at Kiwa PVEL, so we cannot yet comment on MSS results).
While we have highlighted concerns around frames here, manufacturers have also been looking to cut module costs by cutting costs for several other materials and components. As such, module buyers should watch out for other risky cost-saving measures such as thinner encapsulant and poor-quality junction boxes. To protect themselves from high failure rates in the future, it is key for buyers to test the BOM being used in their exact modules, and to keep informed about these market For more information on our coverage of solar technologies, costs and market developments, please get in touch to book a demo of our Solar Technology and Cost Service.
