This company is at the cutting edge of solar panel efficiency

Even after 60 years of commercialization, the technology behind solar photovoltaic panels is still advancing each year — and some of the most advanced panels could soon be manufactured in the U.S.

With its industry-leading efficiency, Maxeon Solar Technologies might be the manufacturer that best demonstrates the ongoing progression of solar power, the fastest-growing form of electricity generation in the U.S. and the world.

Maxeon, which sells premium solar modules at a premium price, carries the technological DNA of the pioneering U.S. solar company it was spun out of in 2020: SunPower. Founded in Silicon Valley in 1985, SunPower distinguished itself with world-record solar cell performance — a technical edge that Maxeon maintains today. SunPower once built solar cells and panels in the U.S., but cost pressures from its competitors’ Chinese-made products pushed the company to move production abroad. Maxeon, for its part, has never produced panels in the U.S., but rather has made its products in Mexico, Malaysia and the Philippines.

Now, pending a loan from the U.S. Department of Energy’s Loan Programs Office, Maxeon is aiming to embrace its U.S. manufacturing lineage. The company has selected Albuquerque, New Mexico as the site for a record-sized silicon solar cell and module factory, a testament to the transformative industrial-policy incentives contained in the Inflation Reduction Act.

The planned factory would produce 3 gigawatts’ worth of solar panels a year, and overall Maxeon is considering plans to expand its U.S. manufacturing operations to an annual capacity of 4.5 gigawatts. For context, the entire U.S. solar industry produced a total of 5 gigawatts of solar panels in 2022. The new factory represents the sort of domestic solar manufacturing growth the U.S. needs in order to achieve its at-times-conflicting goals of installing hundreds of gigawatts of solar energy while also weaning itself off panels made by Chinese firms.

Canary spoke with Matt Dawson, Maxeon’s chief technology officer, for an update on how the company intends to maintain its lead in solar cell technology, which separates it from the deluge of inexpensive but lower-efficiency panels from Asia.

Better and best technologies

Maxeon has two core solar cell technologies.

Its “shingled-cell” technology uses commodity silicon solar cells sectioned into strips that are tiled and stacked a bit like rooftop shingles. The result is a panel that has slightly higher performance simply because of the increased density of active solar cells.

“Up until now, we've been using PERC cells, which has been the commodity cell platform for the last five years, and putting that into our shingle panel. But what we're developing right now is a shingle solution that works with a TOPCon cell,” the next generation of commodity cell technology, said Dawson.

PERC is an acronym for passivated emitter and rear contact, and these cells lead the commodity-class efficiency race today, as TOPCon technology is still in its early stages. PERC cells have a reflective layer underneath to optimize light capture as well as anti-reflective coatings and textures that optimize the conversion of sunlight into electricity.

Dawson said that Maxeon’s shingle technology maximizes the performance of these commodity cells: “We've got a 20-year history of understanding how to make very reliable, very durable products. We took all of that knowledge to produce a panel with higher performance than a comparative commodity panel, but with lower degradation and better reliability.”

It’s the shingled panel technology using a TOPCon cell that Maxeon will be scaling up at its new factory in New Mexico. Those panels will hit 22 percent efficiency when they come out, and the CTO said that he expects that to improve that over time.

In recent years, SunPower targeted the residential and commercial rooftop market, but Maxeon is going “almost exclusively for U.S. utility deployments” with this technology, said Dawson. “It allows us to have a differentiated product in the utility space, but with a product that commands a slight premium because of better performance,” he added.

Maxeon’s other technology is used to produce super-high-efficiency panels for residential rooftops and applications that are less cost-sensitive than utility-scale deployments. These panels use what’s called interdigitated-back-contact or IBC technology. “It's the technology that SunPower was founded around, and for the last 20 years [we have] staked our claim around having the world's best panel,” he said.

Maxeon recently recaptured the world efficiency record for solar panels thanks to the pilot line of its latest generation of IBC technology, managing 24.7 percent apertured efficiency for a full-size module. The firm expects to bring that to market next year. “This allows us to build a 24 percent module at peak efficiency — and we think the technology has room to improve from there.” That module will be built in the Philippines on a line that’s been expanded to 500 megawatts of production capacity.

To put Maxeon’s numbers in perspective, Chinese vendors such as Longi and Jinko top out at 20 to 21 percent efficiency. Canadian Solar specifies its highest-performing module at 22.8 percent.

The next solar frontier

Despite the consistent historic improvement in silicon cell efficiency, physical limits exist — and the industry is rapidly approaching them.

“I think we'll see 25 percent panels and possibly 26 percent panels. I think it's possible that IBC technology can get there,” said Dawson. “If we talk about what's beyond that, it's probably going to be a novel material system. There's a tremendous amount of effort and money and smart people on the perovskite problem.”

But there’s no guarantee that novel solar materials like perovskites (or nanoplasmonics or iron pyrite) will ever be viable for mass production. According to Dawson, that comes down to one question: Can a new technology get to a fundamentally lower levelized cost of electricity than an already-scaled incumbent technology? “We've been doing this now for a very long time and understand how challenging it is to commercialize something and make it durable for what customers now expect to be a 40-year warranty.”

“Because of the scale that crystalline silicon has gotten to, it's going to be very hard to displace,” he said. “We obviously feel that IBC is going to have a very important if not central role in the second half of this decade into the 2030s; we think it’s the next technology node beyond TOPCon.”

The challenging nature of bringing another solar material to market has not discouraged a crowd of technologists from trying. Thin-film solar leader First Solar acquired Sweden’s Evolar, a perovskite developer, in May in a deal valued at up to $80 million. Other startups looking to commercialize perovskite technology include Beyond Silicon, BlueDot Photonics, Caelux, CubicPV, Energy Materials Corp., Microquanta Semiconductor, MujiElectric, Oxford PV, Saule Technologies, SoFab Inks, Swift Solar, Tandem PV, Verde Technologies and UtmoLight. Most of the startups are looking to pair a perovskite layer with a silicon layer and harvest different flavors of light from the two materials.

Maxeon, for its part, is not working on perovskites — it's focused instead on the more tried-and-true method of nudging silicon efficiency up while driving costs down. And it’s looking to ride the wave of generous U.S. clean-energy manufacturing incentives to help it do so.

In the year since the Inflation Reduction Act passed, a number of established solar players including Qcells, First Solar and Enel have already selected sites and in some cases broken ground for new factories or expansions of existing manufacturing facilities. In total, more than 35 new U.S. solar manufacturing facilities or expansions have been announced since the IRA was signed, with a potential combined annual capacity of about 85 gigawatts. Contrast that with the 11 gigawatts of manufacturing capacity the U.S. had last year, a distressingly small 2 percent of the world’s roughly 500 gigawatts’ worth of photovoltaic module production capacity.

The total investment for Maxeon’s proposed 3-gigawatt facility would exceed $1 billion, but Maxeon still has to make it through the due diligence and approval process of the DOE’s Loan Programs Office in order to complete the financing of the project. Should the loan close, Maxeon expects construction to begin in the first quarter of 2024, with the production of panels to start in 2025. Up to 1,800 employees will staff the completed facility.

“The technology that will dominate is the one that can supply the lowest levelized cost of electricity with the lowest overall capital,” Dawson said. “The lowest overall capital footprint for the last decade has been in China because of the massive centralization and vertical integration of the supply chain there. But as more countries become concerned about their energy independence, solar is likely to be manufactured in a lot of places outside of China. We're already seeing that in Southeast Asia — now we're seeing it in the states, and we may see it very soon in Europe.”