TOPCon the likely choice of new U.S. solar manufacturers


With a huge volume of tax credits available to clean technology manufacturers under the Inflation Reduction Act, the U.S. is beginning to see an influx of solar module makers setting up shop. While the clock is ticking on the opportunity to take advantage of the tax credits, establishing a vertically integrated facility quickly is no small task. At the recent RoundtablesUS 23, Jonathan Gifford, editor-in-chief of pv magazine moderated a panel session that discussed what technologies are best suited to both the rapid rollout and also long-term competitiveness.

Panelists include Alex Barrows, head of PV at Exawatt, Tristan Erion-Lorico, VP of sales and marketing at PVEL, MinWah Leung, senior engineer, solar technology at DNV, and Kim Primerano, vice president, energy and infrastructure development, Estuary Power.

In the panel on how the IRA is changing the landscape of solar manufacturing in the U.S., four experts discussed how realistic it is to reduce our dependence on Chinese imports, what the challenges are for manufacturers in setting up shop in the U.S., how we fill in anticipated gaps in the U.S. supply chain, and more. Alex Barrows kicked off the next panel session by noting that while a lot of module manufacturing announcements have come out, not all will get built. But he estimates that if every company does what they say they intend to do, we could have 90 GW of module capacity by 2026, 20 GW of cells and potentially 20 GW of wafer.

Clearly the mismatch in capacity leaves U.S. manufacturers beholden to importing cells and wafers, which presents a myriad of challenges, not the least of which is for developers to claim the domestic content adder. Erion-Lorico pointed out that there’s a lot to be done, but that there are challenges remain, ranging from the current transformer shortage to the challenge of hiring skilled workers. Erion-Lorico sees the workforce issue as a huge challenge. He estimates that we’ll need 4,000 to 5,000 people to run 100 GW of plants.

The TOPCon choice

With the majority of announced manufacturing facilities intending to produce solar modules, the question is, which module technology will be manufactured. MinWah Leung of DNV said that they see TOPCon as the big player. She thinks that heterojunction (HJT) will play a role in the future, but that TOPCon will be “the main technology, at least in the next few years.”

Leung said there are two pieces that DNV looks for in assessing module quality and risk: One is the design of the module—and what the technology risk is in terms of the design of the module. The second piece is the risk in terms of production quality on the manufacturing side. As DNV specializes in assessing risk, she said that it comes down to extended duration testing, which speaks to the design of the module. To assess manufacturing quality DNV also looks at factory audits, production quality, reports, monitoring, and pre inspection reports.

From the developer’s standpoint, Kim Primerano of Estuary Power said that she is risk averse and she doesn’t “usually like to be the first one off the production line”. While Estuary is closely monitoring the buildout of U.S. solar manufacturing, the company is not currently modeling domestic content. She noted that if the numbers that Barrows was projecting come true, it’ll result in the prices coming down while driving capacity up. At that point, she said, Estuary would start to look at domestically manufactured modules.

In terms of technology choice, however, Primerano said Estuary is definitely looking at TOPCon and planning to use it in an upcoming project. Erion-Lorico spoke of what PVEL is finding in its testing. He said both HJT and TOPCon introduce new risks and there’s a range of results, but over time the modules have industry leading low degradation rates. Developing TOPCon is a sensitive process, and the production window is tighter, he said. But they are seeing great results from factories overseas in PID for TOPCon and they’re seeing great results in thermal cycling in HJT. However, he noted that it’s “a wider range that’s going to take time to tighten”.

Another thing we’re starting to see is U.S.-made encapsulants and backsheets, according to Erion-Lorico, which is a result of the push to onshore the whole solar supply chain. He pointed out that this brings risk as well because manufacturers like Trina have long relationships with materials suppliers, they know how the materials will perform. And yet, to get to that 40% domestic content, some manufacturers will be looking to source materials from new U.S. manufacturing lines.

Automation in manufacturing, installation

With these risks come opportunity. Leung pointed out that we’re seeing a lot more automation not just of factories but of solar construction. She that we are starting to see robot and smart technologies being used for manufacturing, delivery, pile driving, mounting modules, and more. “It’s going to require a lot of coordination in the industry between not just module manufacturers, but also mounting system and inverter manufacturers, to EPCs and developers to see how everything can be automated on a larger scale”.

From a quality standpoint, Erion-Lorico said that PVEL has seen good results in automation of manufacturing, especially with glass glass modules. He added that even with multi-busbar modules, such as TOPCon, cell cracks matter less, so that may help to accelerate these less standard transportation methods. Leung added that a benefit that could result from automation is the standardization of mounting and module equipment so it can be installed more quickly.

“With the amount of solar that all of these renewable energy goals are looking towards, and the acceleration of installation, I think it will necessitate some form of automation in the future, Leung said. “It’s an emerging technology and it’s not perhaps quite there yet.”


Looking at emerging module technologies, Barrows noted that there are a number of companies looking at perovskites, but he doesn’t think they can move fast enough toward commercialization to make use of the IRA incentives. He said we’re likely looking at HJT by in the early 2030s, but there’s definitely still a bit of work to be done.

At the same time, there’s a lot of talk about tandem and about that being a path to domestic content advantage, Erion-Lorico said. “Instead of competing with modules from Southeast Asia or elsewhere, the U.S. is actually bringing back innovation and setting ourselves apart on an efficiency and technology level.” He said he’s bullish on tandems and perovskites—“people are working on it and they want to do it in the U.S., so that’s exciting.”

The drawback with perovskites right now, however, is durability. Erion-Lorico expressed optimism, however, because—just as in developing the rest of the solar supply chain, there are a lot of brilliant minds focused on overcoming the challenges.

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