‘World-changing’ solar cells could mean the death of batteries

ejust six seconds, in a factory on the northern outskirts of Stockholm, a top-secret printer spews out sheets worth thousands of euros each. Each contains 108 miniature solar cells that will soon find their way into everyday gadgets – from keyboards to headphones – that will fundamentally change the way we interact with technology. According to their creator, they will even force us to rethink our relationship with light.

Sweden might seem like an unlikely place for a solar revolution, but the lack of light during the winter months was one of the reasons Exeger co-founder Giovanni Fili looked beyond the Sun as the only source of energy for photovoltaic cells. His company’s revolutionary technology can harvest electricity from virtually any light source, from direct sunlight to candlelight. It can even generate a charge from moonlight, though it will take some time to be of much use.

“Like the algae at the bottom of the ocean, where it’s almost dark, we can use very few photons efficiently,” Fili says The Independent. The T-shirt he wears describes his company’s technology as “world-changing,” capable of simultaneously addressing global energy needs and some of our planet’s greatest environmental challenges.

Indoor solar panels have been around for decades. Solar-powered calculators were first introduced in the 1970s, but the limitations of the amorphous silicon cells they rely on mean they are too low-powered, too fragile and too rigid to be integrated into other products.

The latest innovation stems from a discovery made in 1988 related to dye-sensitized solar cells (DSSCs). Two scientists at UC Berkeley in California invented a low-cost, high-efficiency cell that was both semi-flexible and semi-transparent, offering a path to commercial development of the technology.

Just over 20 years later, Fili and Exeger co-founder Henrik Lindström came up with a new electrode material that offered 1,000 times better conductivity. The breakthrough formed the basis of their Powerfoyle cells, which are now being produced on a commercial scale.

Exeger’s Powerfoyle solar cells offer a radical departure from traditional glass-coated panels, eliminating the need for the silver lines you see on them that act as conductors. In addition, they are not sensitive to partial shading, which drastically reduces the efficiency of photovoltaic panels.

The patented leather-like material can even transform into almost any material to allow seamless integration into a huge range of products, while remaining waterproof, dustproof and shockproof.

“It works in all light conditions, is more durable than any other solar cell in the world, is easy to manufacture and can mimic any surface – leather, carbon fiber, wood, polished steel. It’s also beautiful,” says Fili. “So we can integrate into products that are already selling billions of units a year.”

Exeger’s facility in Stockholm has the capacity to produce 2.5 million square meters of solar cells each year, making it the largest factory of its kind in Europe. Speaking at the opening of the factory in 2021, Filley predicted that Exeger’s technology would “touch the lives of one billion people by 2030.”

Powerfoyle solar cells have already found their way into seven finished products – including headphones, wireless speakers and a bike helmet – while six more have been announced. Customers include Adidas, Phillips and 3M, but they are also rumored to be in talks with LogiTech and Apple.

A future without batteries

Exeger is one of several startups pioneering the commercialization of indoor solar panels, with the promise of clean, endless power attracting researchers and entrepreneurs alike.

US-based Ambient Photonics was drawn to the space by the “magical” potential of the smart home, as well as the hope that it would be possible to eliminate the need for disposable batteries.

“The scale at which smart electronics can be implemented is limited by battery life and the use of traditional batteries that require constant charging, stagnant product design and have negative environmental consequences,” Bates Marshall, co-founder and CEO of Ambient Photonics, said The Independent.

TV remotes alone are responsible for throwing away 3.1 billion disposable batteries each year, according to ratings from Samsung. The Korean electronics giant has made switching from alkaline batteries to photovoltaics a priority to meet sustainability targets, claiming it can reduce its greenhouse gas emissions by around 6,000 tonnes a year.

“Each advance in the power density of our product brings us closer to a future where the need for disposable batteries is greatly reduced, if not completely eliminated,” says Marshall.

Ambient Photonics’ DSSCs have so far been integrated into remote controls, although limitations with the amount of heat and light they can be exposed to mean the technology is currently limited to indoor applications.

The flexibility and durability of Exerger’s Powerfoyle means the only limitations are power-hungry devices such as laptops and smartphones – although they could deliver a significant 50-100 percent increase in battery life. Exeger is also researching a solar-powered tablet case that could provide enough power for infrequent users to never need to charge.

“Our grandkids will laugh that we had cables,” Feeley says.

One trend that Fili has noted is that users of Powerfoyle products have become much more aware of their surroundings and the presence of light in their lives. “We make people light-conscious,” he says, “because light is power.”

Fili is driven by the belief that Powerfoyle is era-defining technology. Exeger is the first to commercialize the technology on this scale, though it remains relatively nascent given that Fili views everyone on the planet as a potential user. Others seem confident in his claims, p Forbes likening him to figures such as Jeff Bezos, Bill Gates and Elon Musk.

The technology behind Exeger’s solar cells, as well as the printers that produce them, is a closely guarded secret. Even the purpose of the thousands of Powerfoyles currently being printed every minute at the Stockholm factory is not yet publicly known. (Their elongated shape strongly suggests that they would be used in a product that most of us use every day—the one on which this article is being written.)

“It’s really, really huge,” Fili says. “We’ve just secured a contract with the world’s largest supplier of keyboards and mice, and we’ve already partnered with some of the biggest companies and brands on the planet. This technology is going to take over the world.”