One of the biggest challenges in working with the sun’s energy comes from its bounty. It is everywhere and it comes down (relatively) evenly across the globe. It is dispersed.
“You can’t go to one spot and collect most of it, like you could mining for coal,” said Matthew White, associate professor of physics at the University of Vermont’s College of Engineering and Mathematical Sciences.
To collect a lot of solar power, you have to distribute a lot of solar panels, White said.
In the interest of those goals, a UVM-based startup is working on a promising technology, known as thin film, to capture the sun’s rays much more efficiently than existing panels.
Verde Technologies is working on the technology that involves applying solar cells to — unsurprisingly — thin film. That film can then be applied to pretty much anything from rooftops to aircraft. It enables consumers to install more photovoltaic panels without taking up the large areas needed for panels currently on the market, which are generally large, rigid and clunky.
“You could adhere it to the surface of a (Boeing) 747 without adding a whole lot of weight,” said White, who is not affiliated with Verde but is familiar with their research.
Think about how large an area you could cover with a shipping container of existing solar panels, White said. With a container of rolls of thin-film solar cells, you could cover a much larger area. And a large area is what you need to generate solar power, he said.
One way to apply these solar cells to film is to use tandem solar cells, which are made of stacked materials such as silicon and perovskites, a crystalline mineral also used in such items as sensors and lasers. Together, they absorb more of the solar spectrum than a single material, which increases the efficiency of the solar cells. That means the cells can generate more power.
Companies around the world have been working on this technology. Verde, along with Massachusetts-based CubicPV, is one of two partners selected to work on a center to commercialize perovskites for solar applications, an effort being led by the Massachusetts Institute of Technology.
While the work at MIT is focused on using silicon and perovskites, Verde is focused on making solar cells using only perovskites. Skyler Bagdon, the company’s chief executive officer, said that represents a bigger leap forward in technology.
But making stable and efficient perovskite layers is time-consuming and painstaking.
White said Verde’s advantage over other companies is its knowledge of how perovskite semiconductors are crystallized from a solution after they are laid down and dried on a plastic surface.
At present, the core team at Verde is just three full-time employees, said Bagdon, who works with Chad Miller, the president and chief technology officer, and research scientist Pramod Baral. Much of the work has been completed by UVM undergraduates, Bagdon said.
Essential to the company, but not working full-time for it, is Randall Headrick, who has been studying crystalline films for 40 years and chairs the physics department at the UVM College of Engineering and Mathematical Sciences.
Headrick joined forces with Miller to see if they could use the thin-film manufacturing techniques they had developed for solar panels. The breakthrough technology they are now working on is the ability to scale these techniques to large areas of film, Headrick said.
Headrick also gave Verde its name, which means green in Spanish, Portuguese, Italian and Romanian.
“We believe that solar has the greatest potential of any renewable technology to offset oil as the primary way that we produce electricity,” Bagdon said. “One hour of solar energy hitting the Earth is enough to meet the world’s energy needs for an entire year.”
The main hurdle to solar, Bagdon said, is installation, which he said accounts for 70% of solar’s cost.
Another hurdle is that most solar panels are made in China. The Covid-19 pandemic showed that can come with huge supply-chain problems. Plus, he said, anytime large, heavy objects are moved around the globe, a lot of fossil fuels are needed to do the job.
“If we’re going to increase solar energy adoption, we need panels that are higher performing, easier to install, and can be manufactured domestically,” Bagdon said.
The panels that Verde is working on are 10 times lighter than traditional solar panels, he said, and they can be printed from a liquid ink at existing printing and coating factories like those used for newspapers and beer labels.
But there is a difference.
“Our inks have to turn into semiconductors with a lot of very special properties,” said Headrick. “So it’s way, way more challenging.”
Verde is working on making that process more feasible.
The company is working in labs at the University of Vermont and has contracted with manufacturing partners in Massachusetts and Connecticut.
Headrick expects Verde’s outdoor testing facility at UVM to be set up by fall 2024. Bagdon said the company hopes to start testing with customers on rooftops in 2025.
Bagdon estimates that installing panels on rooftops that cannot accommodate the weight or the rigid shape of conventional solar panels is a $7 billion market in the United States.
But the company has much bigger plans: to serve solar developers installing solar fields to generate power for utilities, Bagdon said. If more solar fields are installed more quickly, with less labor and with solar cells that are more efficient, people could use less land to produce the same amount of solar energy as with traditional solar panels.
Bagdon estimated that, in the coming decade, this will represent a $230 billion to $370 billion market globally.