Last week, State Power Investment Corporation (SPIC) broke ground on a 10 GW high-efficiency heterojunction (HJT) solar cell and module manufacturing project in Suining, Sichuan province.
The factory will be owned and operated by the company's unit SPIC New Energy, which developed a proprietary copper busbar heterojunction (C-HJT) cell technology that replaces silver with copper in the metallization process. This breakthrough could significantly cut key manufacturing process costs compared with conventional silver-based processes, the company claims.
Chief scientist Wang Wei explained to China state media that the technology integrates three innovations: ultra-narrow 9-micron busbars measuring a third the width of silver lines, vacuum-deposited copper interconnects, and proprietary interface engineering.
Lab tests showed the proposed solar cell configuration can achieve a 25.97% power conversion efficiency, with modules hitting 710 W output.
“By solving copper's adhesion challenges through surface treatment, we've greatly increased pull-off strength which is critical for durable rooftop and utility-scale installations,” Wang said. The process reportedly maintains conductivity even with microcracks, addressing a key industry reliability concern.
SPIC's vertical integration strategy combines in-house R&D with equipment partnerships. Its 300 MW pilot line in Wenzhou has already deployed China's first fully domestic copper busbar production tools, with a 600 MW expansion under development. Though pandemic-era supply chains delayed the 5 GW Zhejiang factory, 600 MW became operational last June ahead of full commissioning this year.
The Sichuan expansion positions SPIC to leverage its 30 GW annual renewable energy deployments as a captive buyer.
With silver accounting for around 10% of solar panel costs, SPIC's copper shift comes as manufacturers scramble for alternatives amid volatile precious metal markets.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
By submitting this form you agree to pv magazine using your data for the purposes of publishing your comment.
Your personal data will only be disclosed or otherwise transmitted to third parties for the purposes of spam filtering or if this is necessary for technical maintenance of the website. Any other transfer to third parties will not take place unless this is justified on the basis of applicable data protection regulations or if pv magazine is legally obliged to do so.
You may revoke this consent at any time with effect for the future, in which case your personal data will be deleted immediately. Otherwise, your data will be deleted if pv magazine has processed your request or the purpose of data storage is fulfilled.
Further information on data privacy can be found in our Data Protection Policy.