Details on new multijunction solar cell developed by NREL that’s ready for commercialization

NREL microlink

The National Renewable Energy Laboratory (NREL) has entered into a license agreement with MicroLink Devices, Inc. (Niles, IL) to commercialize NREL’s patented inverted metamorphic (IMM) multijunction solar cells. While high-efficiency multijunction solar cells are commonly used for space satellites, researchers have continued to look for ways to improve cost and performance to enable a broader range of applications.

The IMM technique licensed by MicroLink Devices enables multijunction III-V solar cells to be grown with both higher efficiencies and lower costs than traditional multijunction solar cells by reversing the order in which individual sub-cells are typically grown.

The IMM architecture enables greater power extraction from the higher-bandgap sub-cells and further allows the use of more efficient low-bandgap sub-cell materials such as Indium Gallium Arsenide. In contrast to traditional III-V multijunction solar cells, IMM devices are removed from their growth substrate, allowing the substrate to be reused over multiple growth runs – a significant component in reducing overall device costs. Removing the substrate also reduces the weight of the solar cell, which is important for applications such as solar-powered unmanned aerial vehicles.

MicroLink Devices is an Illinois-based ISO 9001 certified semiconductor manufacturer specializing in removing active semiconductor device layers from their growth substrate via a proprietary epitaxial liftoff (ELO) process. By utilizing its ELO capabilities, MicroLink will be able to make thin, lightweight, and highly flexible IMM solar cells which are ideal for use in unmanned aerial vehicles, space-based vehicles and equipment, and portable power generation applications.

Module Evolution: What big-time PV improvements will boost panel efficiency?

“IMM makes multijunction solar cells practical for a wide variety of weight-, geometry-, and space-constrained applications where high efficiency is critical,” said Jeff Carapella, one of the researchers in NREL’s III-V multijunction materials and devices research group that developed the technology.

“Former NREL Scientist Mark Wanlass pioneered the use of metamorphic buffer layers to form tandem III-V solar cells with three or more junctions. This approach is very synergistic with our ELO process technology, and MicroLink Devices is excited to now be commercializing IMM solar cells for high-performance space and UAV applications,” said Noren Pan, CEO of MicroLink Devices.

MicroLink and NREL have collaborated to evaluate the use of ELO for producing IMM solar cells since 2009, when MicroLink was the recipient of a DOE PV Incubator subcontract from NREL. Tests of MicroLink-produced IMM solar cells conducted at NREL have demonstrated multiple successful substrate reuses and efficiencies exceeding 30%.

NREL has more than 800 technologies available for licensing and continues to engage in advanced research and development of next-generation IMM and ultra-high-efficiency multijunction solar cells with both academic and commercial collaborators.

— Solar Builder magazine

Seraphim USA looks to fill void in domestic module supply

Seraphim factory

At its Jackson facility, 25 percent of the Seraphim workforce comprises military veterans, including the operations and production staff.


Being a large, vertically integrated manufacturer for cells and modules was a solid business practice at one point, and may be again, but that is not the case in the current market. As is often the case aboard this solar coaster though, when one or two companies dip, one or two more start rising.

This is why we wanted to learn more about Seraphim USA — a domestic, pure-play PV module assembler that entered the market in the second quarter of 2016, producing modules out of a 160-MW facility located in Jackson, Miss. The company is already in the top three in terms of U.S. production at scale.

You may be familiar with the Seraphim brand name, which has been up and running in China since 2008 (roughly 6 million modules worldwide), but other than licensing the technology and leveraging the brand name, Seraphim USA is its own independent company, launched by a U.S. venture capital group that saw an opportunity.

When the group looked at forming the company, there was about 1,600 MW of total module manufacturing capacity in the U.S. — representing about 20 percent of total demand. And with the projected growth to 2020, and with the U.S. becoming the second-largest solar user, the Seraphim team saw an opportunity because “supply needed to come back domestically.”

Seraphim USA produces high-efficiency, 60-cell mono and mono PERC panels (300-watt) right now and soon will be producing 72-cell, 350-watt versions.

“We could produce under any label; we toured 16 different module facilities, and Seraphim was above the rest,” says Andrew Fuselier, COO of Seraphim USA. “We struck a deal to license the technology to bring it to the U.S. Because we are coming to market with a proven technology, with a partner that’s been in the market for a long time, we have instant tier 1 bankability.”

Right place and time

Why is Seraphim expanding at a time when larger U.S. module players are struggling?

“We saw too much risk in actually extending cell manufacturing here,” Fuselier says. “We have the capability, but we chose not to in order to hedge against what happened. We were lucky we chose right. We want to let the market float the price of cells and have a diversity of suppliers so we don’t get tied to that. Our analysis says there will be a need for about 4 GW of U.S. production to support market demand by 2021.”

In the three years leading up to its launch in Q3 2016, residential solar was growing, C&I was slowing and utility was steady. The plan to market was to be 30 to 40 percent residential, 30 to 40 percent C&I and the rest OEM agreements and utility.

“We had no real belief that the trend would shift heavily,” says Steve Ostrenga, VP of sales for Seraphim USA. “But then 30 to 40 percent of the module market globally crashed, and a whole new segment of available markets opened up just because of extreme price dropping.”

Seraphim suddenly had more utility interest the last three months than they had anticipated for the full year. The company is already prepping for expansion but remains focused on residential and C&I segments.

“Developers and EPCs are willing to pay a small premium for module certainty,” Ostrenga says. “That’s our message to the market. We’re going to have them available. They won’t get stuck anywhere and you won’t be at the whims of the global market.”

Its location in Mississippi is key here, which allows for quick shipping times to both the East and West coast.

“We can get product out quickly, which saves on costs and lets installers schedule more appropriately,” Fuselier says.

Reducing risk

But speed is nothing if the product fails. Another crucial service component is Seraphim’s PowerGuard insurance policy, which insures the system for the 25-year warranty. So, if the solar coaster happens to claim Seraphim as a victim at some later date, something is still standing behind that warranty.

Taken together, these services have caught the eye of Sunnova and Sungage, which both recently began sourcing Seraphim modules. Soon, they might catch your eye as well.

— Solar Builder magazine

Modules and integration: Four reasons why AC, smart modules are on the rise

The LG NeON 2 ACe

The LG NeON 2 ACe debuts at Intersolar 2017.

At Intersolar 2017, the industry’s newest power couple made its engagement announcement: LG and Enphase have teamed up on an AC module. Known as LG’s NeON 2 ACe, the new product combines LG’s NeON 2 technology with Enphase’s IQ6+ microinverter.

“This changes the basic architecture of an install — the goal is to see the inverter go away and to go plug-and-play,” LG noted at the press event. “This also makes warehousing easier by reducing part count.”

But wait, there is more. Also around Intersolar, Boviet Solar Technology finalized an agreement with SolarEdge Technologies to include SolarEdge power optimizers with its 60-cell mono smart solar modules. Boviet is just one example in a growing list of manufacturers to setup such an arrangement with SolarEdge.

“This new arrangement with SolarEdge gives our customers a single source for both solar panels and power optimizers, which means less equipment to stock and transport to the jobsite,” says John Bereckis, president of the Boviet Solar USA Module Division.

These are just the two most public announcements of MLPE and module marriages — putting faces on a trend that’s been evolving the last few years, whether it is a power optimizer-embedded smart module, a microinverter-embedded AC module, or maybe just a souped-up junction box. Here are some reasons to consider an integrated module, MLPE solution:

1. Streamline purchasing and installation

LG PresentationSolar installers commonly source their solar modules from one vendor and match solar power optimizers supplied by another. By bundling the power optimizer with the module, installers only have to work with a single supplier, which results in savings in both product sourcing and installation. In addition, purchasing solar modules with MLPE pre-installed ensures turnkey functionality and shortens installation time.

“By incorporating MLPE in the module, we eliminate the need to install separate boxes on modules, reducing labor costs,” says Gautam Ghose, senior product marketing manager at Trina Solar. “This enables efficient design and also reduces shipping, inventory tracking and storage costs.”

Trina Solar is currently working with Maxim and Tigo, but says it is pursuing other partnerships as we speak. The integrations are available in the company’s Trinasmart, Trinaswitch and Trinapeak models.

System owners receive the same type of design and efficiency benefits with smart modules that have embedded power optimizers as with the add-on power optimizers. The power optimizers offer MPPT per module, which allows for flexible installation design with multiple orientations, tilts and module types in the same string.

2. Safety

No fretting about meeting any Rapid Shutdown requirements. A smart or AC module is ready to comply right off the bat.

Module Evolution: What big-time PV improvements will boost panel efficiency?

3. More monitoring, less mismatch

Incorporating MLPE into the module at the outset ensures module-level monitoring in each system to help pinpoint system performance issues, resolve those issues and minimize downtime over the life of the system.

“Using smart modules offers a variety of benefits, such as faster installation for labor savings, simplified purchasing and inventory, and easier site logistics,” says Lior Handelsman, VP of marketing and product strategy at SolarEdge.

“With the optimization in Trinasmart and Trinapeak, you increase the energy produced by your PV system by minimizing mismatch losses caused by partial system shading or the varying degradation rates of individual modules,” says Parjanya Rijal, product marketing manager at Trina.

If problems are discovered, each manufacturer notes the simpler serviceability for field replacement in addition to the more granular degree of optimization. The strategy here is to maximize the energy produced from each cell in a module and increase durability by eliminating hotspots.

For example, the NeON ACe provides an integrated web-based solution. Monitor power generation through the internet, anywhere and anytime and utilize an automatic problem diagnosis function. With the LG AC Module mobile app, it’s possible to set up all monitoring configuration steps.

4. Install flexibility

Tigo seems to work with every company on both the module and inverter side to ensure smooth integration of its Flex MLPE TS4 Platform. Tigo emphasizes the importance of selective deployment with its Flex MLPE TS4 platform because different functionalities can be used together in the same system by using different TS4 covers.

“Diodes, monitoring and safety (TS4-D, TS4-M and TS4-S) can be selectively deployed on any size system,” the company notes. “Predictive IV is a feature of the TS4-O and TS4-L, which uses analytical data about the module itself to predict optimal performance conditions. This data is used in conjunction with Tigo’s impedance matching technology, allowing for selective placement only on shaded modules.”

Optimization also enables wiring flexibility: Longer strings, uneven string lengths, layouts and orientations, shade mitigation and so on.

“For example, a residential customer might combine strings of modules of different lengths or tilts. Customers can also have modules at different orientations on the same string,” Rijal says.

In addition to fitting more modules into tight spaces, one can easily add additional panels in the future as power needs increase. These features boost the aesthetic and technical advantages of rooftop solar.

When working with SolarEdge inverters, SolarEdge power optimizers automatically maintain a fixed string voltage, allowing installers even greater flexibility with longer strings and strings of different lengths in order to design optimal PV systems. This means more modules can be installed on the roof for increased system size and longer strings for decreased BoS costs.

This article appeared in the Sept./Oct. issue of Solar Builder magazine. Not a subscriber? It’s free! Get on the list today.

— Solar Builder magazine

Itek Energy cuts ribbon on new solar module manufacturing facility in Washington

Itek Energy solar panels

With the Pacific Northwest’s solar community looking on, Itek Energy’s Founder John Flanagan cut the ribbon to the company’s new 48,000 square-foot manufacturing facility in Bellingham.

With a whole new line of cutting-edge equipment, Itek’s new factory produces high-power, five-busbar solar modules in both 60 and 72 cell, with a power range of 300–370 watts. Known for building quality solar products, Itek’s unique vision of providing the United States with PV modules from high-tech, efficient factories placed close to local markets is well on its way to being fulfilled.

“When we had our first meeting about the waterfront, this was the kind of business that we imagined would be down here,” Mayor Linville said, “Homegrown, able to expand, and good for our environment and our green power.” Mayor Linville also applauded the re-purposing of the old Georgia Pacific warehouse for Itek’s new facility, and the fact that it will bring more jobs to Bellingham’s downtown core. Rob Fix spoke for the Port of Bellingham to share their excitement at the success of this project.

Just before cutting the ribbon, Flanagan spoke to the crowd, thanking the City of Bellingham and Port of Bellingham for their collaboration on the project, and the solar installers—in Washington State and beyond—who support Itek’s business. Flanagan also made a special point of thanking “Itek’s hard-working employees, who made this transition possible.”

Karl Unterschuetz, Director of Business Development for Itek Energy, led the crowd through a tour of the new facility. Unterschuetz pointed out that, with the increased capacity from the new factory, Itek is placed among the largest solar manufacturers in the United States. The new facility will have the ability to produce 150 megawatts a year, and Itek will also keep its existing facility in Bellingham’s Irongate District, bringing Itek’s total capacity to 210 megawatts per year.


— Solar Builder magazine

BASF, SoloPower Systems debut solar-integrated roofing system

BASF solar roof

The next contender in the solar-integrated roofing race: BASF and SoloPower Systems are launching a “multi-layered roofing system” that combines energy efficiency, power generation, waterproofing and water harvesting.

The companies say the seamless multi-layered roofing system can be up to 60% lighter than conventional roofs due to its unique light weight construction materials throughout its design. This solution includes roof panels, waterproofing membrane and solar panels. Using composite structural insulated panels provides a cost-effective way to comply with the national energy efficiency regulations South African National Standards (SANS) 10400XA.

At the launch event, Chairman of SoloPower Systems, Neil Auerbach, said that this product represents the future of the solar roofing industry.

“The ability of this roof to combine, in a single product, best-in-class thermal insulation, water harvesting and solar power generation, puts it ahead of the pack in generating both environmental benefits and rapid payback for customers. I expect this product to change the way roofing and solar is thought about in the commercial and industrial sector,” he said.

BASF Roofing System Component

According to Managing Director of BASF Construction Chemicals South Africa, Angus Peruzzo, South Africa has the best solar conditions in the world. “Incorporating existing technology from Germany and the United States, we have customized the system to enable optimum usage for climatic zones in South Africa. Our collaboration with SoloPower and the launch of this multi-layered system will enable energy and other resources to be harnessed more efficiently for the long-term.”

The technology used for the solar power panels (modules) are CIGS (copper indium gallium selenide) solar cells that produce high energy yields by converting a broader spectrum of light into electrical energy. This technology also allows for the panel construction to be thin and flexible.

— Solar Builder magazine