SunDensity, a solar startup promising 20 percent power output gains* due to specially coated glass, raised $2.5 million in initial financing to begin commercializing its product.

If commercially successful, the technology could measurably increase the output of solar panels, reducing the number of modules needed to produce the same amount of electricity and cutting installation costs.

Rather than increasing the ability of a panel to absorb a wider spectrum of light through more mainstream heterojunction technology, SunDensity's coating, when applied under panel glass, turns blue photons red, allowing greater absorption. The startup says it can be used with any type of panel, from cadmium telluride to perovskite.  

Having long witnessed the solar industry’s plodding process to increase efficiencies, Nish Sonwalkar, the company’s founder and a research professor at the University of Massachusetts-Boston, “started thinking about the problem upside-down.”

“Instead of exposing solar cells to this big spectrum, from 350 nanometers to 1,000 [nanometers], let’s narrow that to be as close [as possible] to the bandgap of a given solar cell,” he told Greentech Media.

Clean Energy Ventures, an investment firm focused on early-stage clean technologies, led the funding round, with support from its partner Clean Energy Venture Group, early-stage investment group Rochester Angel Network and nonprofit venture development firm Launch NY. The round also saw funds invested by Luminate, an accelerator program based in Rochester and funded by the state of New York. SunDensity received $1 million from the accelerator in September.

The startup plans to stay in that region, which, according to Luminate, holds the largest number of optics, photonics and imaging patents in the country, as well as being home to the American Institute for Manufacturing Integrated Photonics.

SunDensity will spend the $2.5 million over the next 18 months, scaling its technology beyond the lab, signing development and production agreements with glass companies, and ramping up overall production.

Sonwalkar told Greentech Media that the company is currently in talks with four large panel manufacturers and eight glass companies that have signed letters of intent for up to 1.5 gigawatts' worth of coated solar panels. SunDensity hopes to begin deliveries by the middle of 2022.

SunDensity is Clean Energy Venture’s eleventh investment since the firm began work on its latest fund in 2019. The group rolled out of Clean Energy Venture Group, which has invested in clean energy companies such as EnergySage, Pika Energy — now part of Generac — and Energetic Insurance. CEV focuses on early-stage investments on the cusp of commercialization, with hopes they’ll hit the market within 12 to 24 months of the investment.

“We can’t necessarily afford to always be betting on moonshots that may take 10 years,” said Temple Fennell, a co-founder and managing director at the group.

SunDensity is not the only photonics-focused solar company in the market, but Fennell says that CEV expects the startup to reach scale more quickly than its peers can. And SunDensity’s technology is also unique, focused on more materials that are more commonplace than those in the semiconductor quantum dots used by competitors.

Using more readily available materials helps lower SunDensity’s overall cost, which Sonwalkar said will only add cents per watt to the cost of the panels while simultaneously increasing power output. Economies of scale will likely mean that the technology, if adopted, will see the most near-term success in large-scale project applications. 

“SunDensity's technology is built on an innovative and promising idea,” said Xiaojing Sun, a senior solar analyst at Wood Mackenzie. “Nevertheless, like all solar technologies, the key to successful commercialization lies in finding the sweet spot between performance and cost." 

Correction: The story originally said SunDensity's product promised module efficiency gains of 20 percent.