Perovskite solar got a $6 million boost

Solar tech developer Tandem PV has raised $6 million for research and development of perovskite cells, and for its first manufacturing facility, the company said today.

• The top line: This additional raise, led by early-stage venture capital firm Planetary Technologies, brings the California-based company’s total financing to $27 million of combined venture capital and government funding.
• The nuts and bolts: Tandem’s design involves stacking silicon solar cells with perovskite materials to absorb varying wavelengths of sunlight. The company said its panels have 26% efficiency — higher than that of silicon panels — and that they can last for decades.
• The market grounding: Since their development a decade ago, perovskite cells have been touted as a more efficient, more flexible, and lower-cost alternative to silicon solar panels. Plus, they’re seen as a workaround to China’s staggering monopoly of global solar supply chains. However, barriers to widespread adoption and commercialization remain.

Tandem PV was founded in Silicon Valley in 2016, and is initially targeting utility-scale projects to use its perovskite cells. Beyond venture capital funds, the company has also received $18 million in public funding through grants from the Department of Energy, the National Science Foundation, and the California Energy Commission.

These funds represent a notable vote of confidence for perovskite solar technology, which has struggled to take off amid problems with component stability and durability, the tech’s overall bankability, and the lack of scalable manufacturing options.

And while the tech remains far from widespread adoption, it has made major gains in efficiency in the last 15 years. At present, though, the DOE’s Solar Technologies Office said perovskite cells aren’t currently commercially viable, because of their short lifetimes. Early iterations of perovskite cells lasted just hours, and today research groups have demonstrated several months of operation. 

And given that SETO “is targeting an operational lifetime of at least 20 years, and preferably more than 30 years,” that means there are major advancements that still need to happen before the technology is viable for commercial, grid-level electricity production.”

Tandem PV hopes its stacked design will fill just that gap, and the company said it will obtain independent industry-standard validation of the durability of its cells this year. However, testing protocols remain a challenge: most protocols today were developed for solar PV, and depend on indoor testing.

Manufacturing also presents a hurdle to the growing number of companies like Tandem that are aiming to bring the technology into the mainstream. According to SETO, producing uniform and high-performance perovskite in a commercial-scale factory is very difficult, and most methods today are difficult to scale.

Tandem first began fundraising for its pilot manufacturing facility, to be based in San Jose, in 2022.