Your browser is not supported. Please update it.

14 January 2021

China solar manufacturing boom hinges on panel size dispute

This week saw the news that JinkoSolar has begun work on a 20 GW solar cell factory which will triple its manufacturing capacity by the end of the year, and that GCL-SI has begun work on a 60 GW manufacturing complex in Hefei city. While opening factories in China is hardly unheard of, the current scale of expansion in the solar industry is unprecedented, vastly more than this year’s global demand of say 130 GW to 150 GW.

Massive expansion also doubles down on the short-term issue of solar glass and polysilicon supply shortage, even if those parts of the supply chain have recovered from their nadir in the second half of 2020. It’s worth noting that polysilicon supply deals covering the next couple years have been signed at an unprecedented scale of late, meaning that some companies at least will be sitting pretty on that front.

In part this massive expansion is because solar power is doing well worldwide and demand is stronger than ever at home and abroad, even as subsidies decline. But a more specific motivation is the advent of larger-sized wafers, with both 182mm and 210mm options set to take over from the current norm of 166mm, which itself is only surpassing 156mm right about now. Besides the lower LCOE that larger wafer sizes bring, there are of course economies of scale to be found from having manufacturing facilities in the tens of GW size range.

It’s anticipated by solar pricing specialist Trendforce Consulting that 182mm and 210mm will together pass 25% market share this year and 50% in 2022, and some reports having these sizes already reaching 30% of current shipments from some companies. The size differences are big enough that for some parts of the manufacturing process it’s not practical to update existing machinery – it needs replacement.

GCL-SI’s 60 GW factory will produce both 182mm and 210mm products, bucking the dichotomy which to some extent developed in 2020 with ‘rival’ associations deciding on one or the other.

The 182mm group was led by JinkoSolar, LONGi, and JA Solar, while the 210mm group initially had a larger number of less prominent companies, Trina Solar being the most important. In particular, the 182mm camp were  ‘vertically integrated’ corporations while this is much less true of the 210mm camp. Perhaps 210mm attracted more smaller players because that option was more speculative, and even less compatible with existing facilities which they had less of. Some important players are signing up for both sizes, so it’s not entirely a war of two parties; but it will drive competition for market share, and that in itself will boost capacity expansion.

That GCL-SI’s facility has both reflects that although ‘bigger is better’, and many parts of a production line have to be designed for one or the other, there are still some ways in which the 182mm option is more practical than 210mm.

For one thing, the resulting modules are lighter and easier for construction workers to deploy; upscaling module power from 300 W to 545 W or beyond (the 210m camp offers 600 W+ modules), also means the weight goes beyond the old standard weight of 20 kilograms or so, and there’s only so much weight you want to be shifting around on a rooftop. One 800 W module displayed at the SNEC exhibition was an absolute mammoth – difficult to carry around.

For another thing, the 182mm modules stack more tightly into a standard shipping container, and require less adjustment from suppliers of rackers and inverters. Lastly, the smaller option has a less strenuous technical challenge to face when it comes to keeping current and resistance losses low.