After the Inflation Reduction Act was introduced in 2022, most of the investments into new solar PV manufacturing in the United States were directed towards module assembly capacity, with effective c-Si module capacity levels reaching about 50 GW by the end of 2025.
This focus on final module assembly of silicon-based solar panels occurred in part due to the attractive production incentives on offer for module suppliers (7c/W) and the existing channels still available for shipping solar cells from Southeast Asia (mostly from Indonesia).
However, the main question related to the United States having a domestic silicon-based manufacturing ecosystem during 2023 and 2024 was on solar cell investments in the country and how this would come to fruition.
One of the first companies to move on solar cell production in the United States was ES Foundry, seeking to specialize at the cell stage – in contrast to other domestic manufacturers such as Qcells, T1 Energy and Canadian Solar (now CS PowerTech) whose cell plans were part of staged integrated cell/module in-house operations.
Two years on from ES Foundry’s initial announcement of its cell manufacturing plans in the United States, I decided to take a deep dive into the progress of the company and what can be learned by the domestic PV sector as increased cell-specific capital expenditure is released.
With these topics centre stage at the forthcoming Solar Manufacturing USA 2026 event in Austin, Texas on 22-23 September 2026 – including a 20-minute presentation from ES Foundry on Day One of the conference – I reached out to ES Foundry’s CEO Alex Zhu to contribute additional commentary in this feature article.
Before diving into the details, let’s look quickly at the company’s ‘entrance’ to the sector.
Early in 2024, ES Foundry announced plans to retrofit an existing manufacturing facility in Greenwood, South Carolina to establish a 1 GW solar cell production line. The building had originally been part of Fujifilm’s Greenwood manufacturing hub (equipped with cleanrooms) from 1988 producing disposable cameras, photographic paper and printing plates.
The entire site was acquired in December 2022 by real estate firm Phoenix Investors that leased part of the area back to Fujifilm to allow for its scaled down domestic market activities. Similarly, ES Foundry signed a long-term lease with Phoenix in 2024, effectively making ES Foundry and Fujifilm co-tenants on the overall site that also includes a distribution centre for VELUX Group.
During the second half of 2024, ES Foundry’s facility was retrofitted to allow solar cell operations based on the technology choice of p-type PERC. Initial production started early 2025 with offtake agreements announced. By the end of 2025, the 1 GW cell production line had been fully ramped, leading to the company announcing plans for an expansion to 3 GW of cell capacity by the middle of 2026, confirmed recently in press releases.
To understand more about this initial phase of the company’s growth, I can now bring in Alex to help.
What were the key factors in the original decision to retrofit an existing manufacturing facility and not go for a greenfield site approach? And what do estimate were the savings in terms of time to reach initial production and in cost terms for the original capex involved?
[Alex]
Three factors typically slow a greenfield manufacturing project: power infrastructure, permitting and workforce. The Greenwood site offered significant advantages in all three areas. It already had robust power infrastructure, wastewater treatment capabilities compatible with our manufacturing processes and access to an experienced local workforce. At its peak, Fujifilm employed about 1,200 people at this campus, which resulted in a strong base of manufacturing expertise in the community.
Retrofitting the facility allowed us to begin production sooner and with substantially less upfront capital than would have been required for a greenfield development. While we have not disclosed specific time or cost savings, the existing infrastructure was critical to accelerating our path to commercial production.
Did the original refitting of the facility have expansion of cell capacity factored in, aside from the initial 1 GW production line? And what is possible in the existing building in terms of cell capacity, before having to look for a second site?
[Alex]
From the outset, we designed the Greenwood facility to accommodate up to 3 GW of annual cell production. We divided the buildout into two phases, beginning with the initial 1 GW line and then adding 2 GW. This phased approach allowed us to demonstrate that we could successfully transform an older industrial building into a modern solar cell manufacturing facility before completing the full expansion.
The existing building has now reached its planned 3 GW capacity. Any expansion beyond that would require an additional location.
One of the key issues the entire U.S. PV manufacturing sector is tracking today relates to cell manufacturing viability, from a yield and profitability standpoint. Ultimately, this will determine which cell manufacturers become the dominant suppliers in the domestic production landscape from 2030 onwards.
At what point did you decide that the move to 1 GW to 3 GW was justified? Were there certain yield and cost targets that needed to be satisfied first with the 1 GW line?
[Alex]
The move from 1 GW to 3 GW was part of our plan from the beginning, rather than a decision made only after the first line began operating. Because the facility’s infrastructure was designed to support 3 GW, operating at just 1 GW carried higher unit costs and did not capture the efficiencies of the full buildout.
During the initial ramp, we closely monitored yield, quality, throughput and operating costs, but the expansion was not dependent on any single target. We expect to realize the facility’s intended economies of scale once the full 3 GW is ramped by the end of 2026.
We do not expect to compete with Asian manufacturing on labor costs alone. Our value comes from efficient production at scale, reliable domestic supply and the benefits of manufacturing solar cells in the United States.
At this point, it is worth looking at some of the issues in terms of operating a cell line, in particular the materials supply and consumables.
Apart from the wafers required, cell production lines generally require high-purity process gases for films and layers, texturing and cleaning chemicals, quartz tubes for diffusion, metallization paste and screen-printing masks.
In terms of the cost-of-goods for running a cell line, this is dominated by metallization paste, with the market dominated since 2020 by Chinese companies.
The supply of metallization paste used in solar cell production has been dominated by Chinese companies since 2020, with the market leaders, DKEM and Fusion, accounting for more than half of the supply volumes in 2025.
Ideally, materials supply for solar cell production in the United States should come from domestic production facilities. Are you seeing any movement from materials suppliers to establish production sites that could decrease the reliance of Asian supply chains?
[Alex]
Yes, we are seeing growing interest from suppliers across nearly every major input category, including metallization paste, screens, chemicals and industrial gases, in establishing or expanding U.S. operations.
That shift will take time. Suppliers need sufficient and sustained demand from U.S. cell manufacturers to justify the capital required for domestic production. As U.S. cell manufacturing capacity grows, I believe that demand will support a broader domestic supply chain and gradually reduce reliance on imports from Asia.
And specifically on wafer production in the United States, this has been somewhat slow to emerge, with Corning and Qcells potentially having minimal availability to third parties given a broader value-chain participation from each. What do you think will be the catalysts to drive further investments into the U.S. ingot and wafer segments?
[Alex]
Recent Section 232 action on polysilicon could be an important catalyst by creating more predictable market conditions and improving the investment case across the domestic supply chain, including ingot and wafer production. That stability can give companies greater confidence to make the significant capital investments these facilities require.
However, policy support alone will not create a durable industry. Solar ultimately competes on cost in the end-user energy market. We need to use this policy window to build scale, strengthen our technology and operating capabilities and establish a healthy domestic supply chain that can compete over the long term. The ultimate goal remains delivering affordable, reliable and sustainable energy.
Workforce availability is another issue being discussed by the U.S. solar industry today. How has ES Foundry addressed this issue since 2025? Are there any key initiatives that could be adopted across the sector as a whole?
[Alex]
Training is the answer, but it requires a sustained investment of time and resources. Rebuilding the U.S. workforce for solar cell manufacturing won’t and can’t happen overnight.
ES Foundry is working with the MIT Initiative for New Manufacturing and here in Greenwood we are partnering with the Piedmont Technical College to develop a training program tailored to our manufacturing needs. This program will introduce local students to modern manufacturing, help them develop relevant technical skills and prepare them for long-term careers in the industry.
This type of partnership among manufacturers, universities and local community colleges could serve as a model across the sector. Workforce development is most effective when training is closely connected to the skills employers need and the career opportunities available in the local community.
Has the scaling of capacity from 1 GW to 3 GW created any new challenges from a workforce perspective? And on this topic, when do you expect the extra cell capacity to reach full production levels?
[Alex]
Scaling from 1 GW to 3 GW has required us to continue hiring locally while also expanding our investment in training. The challenge is not simply adding more people but preparing them to work in a more automated manufacturing environment.
As part of the expansion, we introduced automated guided vehicle systems and other advanced equipment. Our employees must develop the skills to operate, monitor and troubleshoot these systems effectively. We expect the full 3 GW of capacity to be ramped by the end of 2026.
Moving on to cell technology, the choice of ES Foundry for PERC is interesting. Let’s take a few moments to put this into perspective.
PERC was the dominant technology in the PV sector globally for several years, up to 2023. Consequently, bifacial mono PERC based modules are currently powering a high percentage of solar farms globally, with the U.S. no exception to this trend.
PERC based cells accounted for about 65% of global production volumes back in 2023, down from levels above 80% a couple of years before this. TOPCon production volumes, driven by the shift in China from p-type to n-type cell production.
During 2025, production volumes of PERC were still above 50 GW – more than 20% higher than the cumulative production of the other TOPCon options, HJT and back-contact.
The top-20 cell producers globally accounted for more than 93% of silicon-based output during the period 2023-2025, with TOPCon dominating the technology-choice. Modest volumes of PERC, HJT and back-contact accounted for about 15% of cell production in 2025.
Besides the known issues in the U.S. market today related to Intellectual Property concerns on TOPCon, what other factors were important at ES Foundry in choosing PERC? And was there any consideration for HJT or back-contact cell options at the time?
[Alex]
Our decision was not based solely on the intellectual property questions surrounding TOPCon. PERC is a mature, well-established technology with a strong reliability record and a robust manufacturing process window. That makes it easier to achieve consistent quality and yields while training a new workforce and rebuilding domestic expertise in solar cell manufacturing.
Although HJT and back-contact architectures offer potential advantages, they require different processes, equipment and technical expertise. For ES Foundry’s initial manufacturing platform, PERC offered the best balance of performance, reliability, manufacturability and ramp-up risk.
What are your thoughts on some of the other plans for cell investments in the United States for HJT? It seems that the companies choosing HJT are looking at more integrated operations across cell/module, as opposed to being pure-play cell companies. Is this significant?
[Alex]
It is a classic chicken-and-egg challenge. As a pure-play cell manufacturer, ES Foundry needs to produce cells that can be readily incorporated into existing module manufacturing lines. PERC was the best fit because it is broadly compatible with the equipment and processes already used by module manufacturers.
HJT can require specialized module assembly equipment and processes to achieve its full cost and performance benefits, including reducing silver consumption. An integrated cell and module manufacturer can coordinate those investments across both operations. If we had started with HJT, we might also have needed to enter module manufacturing to support adoption. So yes, the integrated model can be particularly significant for companies pursuing HJT.
Efficiency levels have become somewhat secondary in purchasing decisions of recent. It seems that derisking supply channels is more important, while proven technology choice is also a factor for module buyers in the United States. Does this deprioritize somewhat the push to squeeze out the last few efficiency points from PERC cells, or is this technology now mature and operating at its maximum performance level?
[Alex]
PERC is a mature and extensively studied technology, so the opportunity for significant additional efficiency gains is limited. That does not mean efficiency is unimportant, but incremental improvements must be weighed against reliability, manufacturability and consistent product availability.
For many of our customers, securing a dependable supply of proven cells is the more immediate priority. A substantial amount of U.S. cell capacity has been announced since 2022, but relatively little of it is actually operating today. That gap between announced capacity and available product is why execution and supply certainty matter so much in current purchasing decisions.
With the U.S. industry now focused on scaling overall cell production volumes in the coming years, the performance of ES Foundry as a trailblazer in this regard is clearly important to understand.
However, the company’s plans to 2030 and beyond could be far more interesting to understand. In this regard, I am delighted that ES Foundry will be speaking at the forthcoming Solar Manufacturing USA 2026 conference in Austin, Texas on 22-23 September 2026.
The presentation from ES Foundry is part of a series of talks during the event focused specifically at pure-play solar cell investments in the United States.
Details on how to register to attend the conference can be found at the event portal here.
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