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Tandem PV, based in Silicon Valley, was founded in 2016 in response to the urgent imperative for a swift global transition to net carbon zero. Solar power is now the world's cheapest energy source, but we must accelerate its exceptional growth to address our current critical environmental challenges.

Our founder and CTO, Colin Bailie, took on this challenge while earning his doctorate at Stanford University. There, he published seminal research on a then-new class of solar technology: perovskite-based tandem panels.


Chris Eberspacher, a solar energy innovator who had been working to mainstream solar since the 1980s, was so impressed with Bailie's groundbreaking R&D that he signed up as co-founder. At the time, Bailie was an Activate fellow at Cyclotron Road, the prestigious U.S. Department of Energy startup accelerator based at Lawrence Berkeley National Laboratory supporting innovations aimed at global impact.


Meanwhile, Scott Wharton met Rob Carlson, managing director of the VC firm Planetary Strategies, at DLD (Digital – Life – Design), Europe’s leading innovation conference for visionaries from around the globe. Wharton had never heard of perovskite, but he had been fascinated by solar since his 20s. Tandem PV, funded by Planetary from the start, realized that Wharton’s extensive experience could turbocharge the company’s commercialization goals. Tandem PV allowed Wharton to realize his dream and to begin doing his part to bring about a carbon-free economy.


“From the start of my doctoral studies, my advisor and I could see that low-cost tandems were the next frontier. Perovskite technology provided a platform for the perfect marriage with silicon and the idea of turning that potential into a commercial reality that could provide widespread climate benefits led me to launch Tandem PV.”

- Colin Bailie


"I have had the good fortune to combine my experience in PV technology, products and strategy with Colin's experience and skills in perovskite materials and device science to help make perovskite-silicon tandems a commercial reality."

- Chris Eberspacher


“Everything just lined up—the timing, the complementary nature of our skills, the need to add commercial experience and scale Tandem, Colin's desire to focus more on tech. One thing led to another and I’m incredibly excited to be involved with such a superbly innovative company with cutting-edge technology and a world-class team."

- Scott Wharton

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Our Journey





Our Leadership Team

We are a close-knit team driven to help build a cleaner energy future. This collective passion for change brought us together and inspires us to push the boundaries of science and technology. Our team possesses deep technical, manufacturing and scale-up expertise and we have key technology patents and partnerships with academia and government, including with the U.S. Dept. of Energy, the National Science Foundation, the California Energy Commission and the Lawrence Berkeley National Laboratory.


Scott Wharton


Prior to joining Tandem, Wharton was Vice President and General Manager of Logitech B2B, a division that generates roughly $2 billion in annual revenue and includes all products, software and services for business and enterprise customers. Before leading the B2B group, Wharton drove 25x growth in Logitech's video collaboration division, building it from a small player in 2015 ($62 million) to the global market leader for video equipment generating over $1 billion annually. Under his leadership, Logitech developed award-winning products recognized by CES, iF Design, Red Dot, TIME and Fast Company for design innovation.

Wharton has held market-leading roles throughout his career in the communications space including as the founder of Vidtel, a pioneer in cloud-based video conferencing services. Vidtel had a successful exit in 2013.

Wharton was an early executive at BroadSoft (IPO; acquired by Cisco) and VocalTec (IPO) where he spearheaded numerous groundbreaking initiatives, including the development of the first commercial VoIP product, the creation of the cloud PBX market and the VoIP service provider industry. He holds an MBA from Yale University.

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Colin Bailie

Founder & CTO

As a doctoral candidate at Stanford University, Bailie performed seminal research on a then-new class of solar technology—perovskite-based tandem panels—which have the potential to substantially improve the power output of conventional solar modules. Bailie co-founded Tandem PV with Chris Eberspacher, our managing director, while an Activate fellow at Cyclotron Road, the U.S. Department of Energy startup accelerator based at Lawrence Berkeley National Laboratory. Bailie holds a Ph.D. in materials science and engineering from Stanford University and a B.S. in mechanical engineering from Texas A&M University. He was named by Forbes Magazine as one of the top 30 leaders in the world under 30.

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Chris Eberspacher

Co-founder & Managing Director

Eberspacher has worked in the solar energy industry for over 35 years with some of the world's leading solar innovators. Prior to co-founding Tandem PV, he led solar technology development at Hanwha Solar, a global leader in green energy solutions, and SoloPower Systems, an early developer of thin-film solar technology. Prior to that, he held senior solar technology posts at Nanosolar and Applied Materials and co-founded Unisun, where he led the development of innovative non-vacuum processes for fabricating thin-film PV. Early in his career, Eberspacher led research and development teams that pioneered thin-film CIGS photovoltaic materials, processes and product designs at ARCO Solar/Siemens Solar Industries. He holds a Ph.D. in applied physics from Stanford University and a B.S. in physics from the University of Texas at Austin.



Tandem PV in the news

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