First Solar Expands Its CdTe Solar Cell Footprint In The US

Support CleanTechnica’s work through a Substack subscription or on Stripe.

The US solar industry will fail to meet expectations for added capacity if the current state of federal energy policy continues on its misbegotten track, but that doesn’t mean all progress has halted. Take the US firm First Solar, for example. Instead of retrenching, the company is expanding its US operations to meet the demand for its signature CdTe solar cell technology.

CdTe Vs. Silicon Solar Panels

CdTe stands for cadmium telluride, a crystalline compound of the heavy metal cadmium with the metalloid tellurium. Though less efficient at converting sunlight to electricity than more familiar silicon solar cells, the CdTe formula has achieved key improvements in manufacturing costs and durability advantages over the years, leading to an increase in its share of the US utility-scale solar market to 30% by 2022.

First Solar has been instrumental in pushing the CdTe envelope here in the US. The company is a familiar face on the CleanTechnica radar, having improved its thin film technology step by step since launching in 1999. The pace of progress has been relatively quick since then, building on a foundation laid by the startup’s initial iteration as the firm Solar Cells. By 2013, for example, First Solar was reporting a conversion efficiency of 18.7% for its CdTe solar cell.

Working with a research team at the National Renewable Energy Laboratory in Colorado, in 2019, First Solar reported a conversion efficiency topping 20%, marking a milestone towards the company’s long term goal of 28% by 2030. The researchers — eight from NREL and nine from First Solar — also simplified the manufacturing process by eliminating copper from the list additives commonly used in formulating CdTe solar cells.

Next Steps For First Solar

As First Solar emphasizes, solar conversion efficiency in the lab does not necessarily reflect power delivery and durability under long term, real world conditions. In 1995, under its former Solar Cells iteration, First Solar began participating in a long term, real-world study of solar cell durability at the National Renewable Energy Laboratory in Colorado. The study concluded in 2020 with First Solar demonstrating that its CdTe technology still retained 88% of its conversion efficiency after 25 years. First Solar later upped the mark to more than 90%.

Meanwhile, First Solar has also been working the cost-cutting angle. In 2018, for example, the company introduced its Series 5 commercial solar panel with a respectable conversion efficiency of 16.4%. The new panel deployed a larger surface area to help reduce the cost of mounting structures.

Jumping ahead to the latest news, on Friday, First Solar announced the start of construction on a new 3.7-gigawatt factory for its Series 6 thin film technology, adding to its already considerable manufacturing footprint in the US. Construction Review Online was among the news organizations to report on the project. The location is still under negotiation as of this writing, but if all goes according to plan, the facility will begin initial operations by the end of next year. A ramp-up to full volume production will follow during the first six months of 2027.

CdTe Solar Cells Go To The Moon

The high-speed train wreck that passes for today’s federal government aside, the US Department of Energy has persistently promoted CdTe technology as an economical, sustainable, and secure form of photovoltaic technology.

As a thin film, CdTe can be sprayed onto glass for ease of fabricating solar modules. Thin-film solar cells can also be sprayed, painted, or printed onto flexible surfaces. Being lighter than silicon, thin-film technology can also be applied to buildings and other infrastructure where conventional silicon panels would be impractical.

While First Solar has been pushing the manufacturing angle here on Earth, further research into CdTe technology continues apace. That includes potential applications in space. So far, the space field has relied on silicon or exotic multi-junction formulations. However, the recent explosion of activity in the space industry calls for a renewed focus on light weight, flexibility, durability, and high-volume manufacturing alongside lower costs.

In July, for example, Swansea and Loughborough Universities in the UK announced plans to fabricate CdTe solar cells on a substrate of ultra-thin glass, aimed at catapulting the UK to the front of the space solar race.

“With the global space industry booming—valued at £17.5 billion in the UK alone—the demand for efficient, scalable solar power is rapidly growing,” the two schools note. “The European Space Agency predicts a leap from just 1 MWp/year to 10 GWp/year of space solar demand by 2035, driven by expansion of satellite constellations like SpaceX’s Starlink and the rise of space-based manufacturing, including semiconductors and fiber optics.”

The researchers have already reported a 23.1 conversion efficiency on Earth. Under the new program, they are targeting 20% efficiency in space with the help of a six-member partnership composed of the Canadian firm 5N Plus and CTF Solar of Germany along with the UK companies AIXTRON and Teledyne Qioptiq, and the UK’s Manufacturing Technology Centre and Satellite Applications Catapult.

More CdTe For The USA

Meanwhile, back in August of 2022, the Department of Energy (such as it was at the time) launched a new three-year, $20 million program called the Cadmium Telluride Accelerator Consortium. The aim was to ratchet manufacturing costs down while improving conversion efficiency, setting a goal of 26% by 2030.

“Commercially produced CdTe panels also have the lowest carbon and water footprints and the fastest energy payback times of panels available today,” the Energy Department noted.

The competitive grant was awarded to a team comprised of the University of Toledo, Colorado State University, First Solar, and Sivananthan Laboratories, a technology incubator modeled on the foundational research programs of Bell Labs, where the first practical solar silicon cell was introduced in 1954.

Presumably, the $20 million has been already dedicated to productive research, where it is safe from the clawing hands of the Trump administration. Meanwhile, new developments continue to surface in the US. In May, for example, a research team based at New York University reported on a new method for avoiding damage to solar cells during the manufacturing process.

The team focused its attention on a delicate maneuver in which the metal wiring is applied to the solar cell under high heat.

To prevent damage to the solar material during the process, the team applied a thin layer of a buffer material, consisting of aluminum gallium oxide or, alternatively, silicon oxide. “The coating naturally collects at these vulnerable boundaries between crystal regions, protecting them while leaving the rest of the surface clear for electrical contact,” NYU reported.

“This simple and scalable solution has led to major improvements in the cells’ electrical output, increasing the maximum voltage they can produce by 13% and boosting their overall power generation,” the school added.

Simple and scalable that may be, but the US solar industry could sure use a return to supportive federal policy right now. For that matter, the rest of the US could use some help. While US President Donald Trump has his mind elsewhere, electricity demand is skyrocketing and solar remains the least expensive, most abundant, and fastest means of adding more power generation capacity to the nation’s grid.

Photo (cropped): The US manufacturer First Solar plans to build a new 3.7-gigawatt factory, aimed at pushing more CdTe solar cell technology into the market (courtesy of First Solar).