N-type solar development

N-type capacity

Orders for n-type products remain low. Manufacturers mainly gear up for n-type technology this year, with capacity significantly higher than production. Having expanded, mono PERC now sees signs of decrease in profitability. Several manufacturers revealed that they will stop adding PERC capacity, as it’s already in surplus. Projects for the second half of the year are mostly n-type technology roadmaps or high-end technology research. It will take a while for n-type technology to reach large-scale commercial production.

Progress by larger manufacturers in 2021 will determine whether n-type can achieve mass production. The industry is watching whether Longi’s TOPCon and Tongwei’s 1 GW HJT capacity expansion projects materialize by early 2022, bringing costs down. Eyes are also on the yield rate of TOPCon and the selection of equipment for these processes.

Equipment capex for TOPCon dropped in 2020 to a level slightly higher than PERC. Taking into account equipment compatibility and the ability to increase cell efficiencies after switching from PERC to TOPCon, many new PERC production lines have been earmarked for upgrade to TOPCon. If TOPCon process can help increase efficiencies of existing cells and stabilize yield rate, real TOPCon capacity and production will exceed HJT. Technically, manufacturers are still choosing between LPCVD and PECVD, and the issue of wraparound polysilicon layer remains to be solved.

HJT processing is simpler and has advantages on yield rate and efficiencies. After introducing light-soaking last year, overall cell efficiencies increased to more than 24%. However, cost reduction remains a bottleneck. With the emergence of Chinese HJT equipment suppliers and their continued optimization, the capex for a 1 GW HJT cell production line has declined to CNY 450 million ($61 million)/GW. In addition to cost reduction through decreased equipment capex, adopting multi-busbars or smart wire interconnection can drive efficiencies up and silver paste consumption down. Meanwhile, R&D in silver pastes continues, hoping for a technical breakthrough with different materials.

High costs put most manufacturers in wait-and-see mode. Except for Tongwei and HuaSun, most capacity expansion projects this year are at pilot scale. Future development depends on whether HJT expansion in the second half can bring down the cost per watt. The depreciation of equipment brings limited cost reduction, after equipment costs declined from an annual CNY 800 million/1 GW last year to this year’s CNY 450 million/ 1 GW. Further cost reduction can only depend on the advancement of silver paste technology, as well as economies of scale. For HJT capacity and production to grow in the long term, HJT must narrow the gap of costs with p-type.

Continuous progress

TOPCon and HJT both see continuous progress in cost control and efficiencies. The two are projected to see expansion in capacity and production in the next one to three years. However, TOPCon has advantages over HJT in order volume and capacity expansion, as it is easier to be upgraded from PERC. As a result, TOPCon will outpace HJT in terms of capacity and production in the short term. If costs for equipment and silver paste can decrease continuously while production volume increases, HJT will have more room for cost reduction for each high-cost material. Moreover, as HJT cell efficiencies continue to improve, its capacity and production will grow long term.

TOPCon and HJT face challenges in the large wafer transition. While 182 mm and 210 mm will become the mainstream format for p-type in the second half of the year, it remains a barrier for n-type to overcome stability issues using large wafers. If n-type cells made with large wafers can go into mass production in the next two years, costs will fall immediately.

Mono PERC is showing signs of decline after large-scale expansion, so it becomes increasingly important to prepare for next-generation technologies. But as it will take time for n-type to reach commercial production, large manufacturers’ materialization of capacity expansion projects, the degree of cost reduction, mass production efficiency, as well as yield rate control, 2021 and 2022 will be a key period for the evaluation of manufacturers.

About the author

Amy Fang focuses on research and analysis of the solar cell segment of the supply chain. She supports PV InfoLink in producing market trend analysis and works across price forecast and production capacity data services. Fang continues to contribute to solar cell technology research efforts, analysis of market trends, and timely market information.