Two men are sitting on a plane leaning over a napkin. The napkin is full of scribbles, though it just might be the recipe for something the world has never seen before: a solar cell that can be integrated into any device.
In 2009, Giovanni Fili founded the Swedish clean tech company Exeger. The initial idea was to create a transparent solar cell to cover skyscrapers with tinted solar windows. Because in warmer climates windows are already tinted, Giovanni wanted to take advantage of the unwanted light to generate clean energy for use inside the buildings.
That idea turned into something else during a plane trip with Henrik Lindström, one of the pioneers of the dye-sensitized solar cell industry. As a chemist and technical scientist with a doctorate in battery and dye-sensitised solar cell research. Dr Lindström was the perfect partner to Fili who stems from an entrepreneurial background with a Master of Sciences in Business and Administration with a double major in Finance and Information Management from the Stockholm School of Economics
Fili and Lindström brought their minds together to develop a new solar cell material. It has 1 000 times better conductivity than the electrode material found in other solar cells and is layered under the light absorbing surface. This absorbing layer is where we typically see silver connecting lines in other solar technologies.
“In regular solar cells, if you don't have those silver lines, the panel heats up and doesn't produce energy,” says Alexandre Faust, the Head of Communication at Exeger. "Our solar cells don't need those lines because the solar cell itself conducts the electricity so well.”
Exeger produces a flexible material based on the dye-sensitised solar cell technology, making it very efficient in converting indoor and outdoor light into electricity. The material can be incorporated into everyday devices, so that they charge on natural or artificial light. This can lead to products that no longer need to rely on disposable batteries, like the 3M Peltor product recently launched on the market.
“Because we don't need those silver lines, suddenly we can do pretty much anything we want when it comes to design,” says Faust. “We can make solar cells that are triangular or the shape of a fruit. We can also make them in any texture. That gives our customers a lot of freedom.”
European backing for solar innovation
The company prints the solar cells using screen-printing, similar to what shops use to print T-shirts. They can print one square metre of solar cells every six seconds.
Exeger decided to call it Powerfoyle.
This material is now being used in everyday products like headphones, speakers, and helmets created by several major companies around the world, with new product application announced such as remote controls and electronic shelf labels.
The European Investment Bank signed a loan agreement worth up to €35 million for scaling up Exeger’s innovative solar cell technology. The loan is backed by a guarantee from InvestEU. The aim is to help the company expand its operations with the expansion of their second production factory in Kista, outside Stockholm.
“This project is perfect for us because we can take an extra risk as the EU climate bank,” says Eoin Keane, a European Investment Bank engineer. “It could change the solar energy market in Europe, but it could also change how we interact with everyday technology.”
The new factory runs on 100% renewable energy and will produce over 2.5 million square metres of Powerfoyle per year once fully scaled.
- Read more about projects strengthen Europe’s energy autonomy
What are dye-sensitised solar cells?
A dye-sensitised solar cell is a type of photovoltaic device that converts sunlight into electrical energy through a process that mimics natural photosynthesis.
Dye-sensitised solar cells are thinner and more flexible than older solar cells. While these cells are quite efficient, they aren’t widely used because they are expensive to produce due to the cost of conductive materials. The cells are made with a transparent plate covered with a conductive material called indium tin oxide. Below that is a layer of dye, usually a dark colour, that absorbs sunlight and releases electrons.
While on their flight, Lindström and Fili realised that the high cost of indium tin oxide was an obstacle to their idea and immediately thought of a solution: remove the indium altogether.
They ended up creating a new electrode layer with 1000 times better conductivity, which they decided to place behind the dye layer to avoid blocking sunlight. That optimised the absorption of light and opened-up a wide variety of design features.
Unlimited battery life to reduce electronic waste
One of the main benefits of Powerfoyle is the constant generation of energy which in turns charges the products. It integrates seamlessly into devices, ensuring they remain charged without the need for frequent battery replacements or external power sources.
Think about it. Going out for a run with a pair of solar-charging headphones. They charge as you run and, once you return home, you can simply place them on the windowsill or in a bright spot, instead of plugging it in. By turning indoor and outdoor light into clean energy, Powerfoyle cuts down on electronic waste.
The company estimates it will avert the usage of over 1 billion disposable batteries worldwide and save the equivalent of 3.1 billion kilograms of carbon dioxide per year with their first factory alone.
To date, Powefoyle is found in eight products on the market. Exeger announced seven new products earlier this year, with production starting during the second half of 2024. The 3M Peltor hearing protector has already reached the market in April of this year.
“I'm proud that the European Investment Bank can provide Exeger with the means to develop their product further,” says Céline Rottier, an investment officer at the European Investment Bank. “There's definitely a market for it, especially in Europe.”
A flexible solar-cell material
Powerfoyle is also unique, because of its flexibility. Companies can integrate its self-charging capabilities into their products without compromising on visual aesthetics.
Exeger has partnered with several well-known companies to integrate their Powerfoyle solar cell into various consumer electronics products, The latest being 3M.
Other major partners include:
- Urbanista, designer of audio equipment like headphones and speakers.
- 3M, an American multinational involved in industry, worker safety and healthcare.
- POC, the leading manufacturer of helmets for snow sports and cycling.
- Philips, one of the world’s largest consumer electronics companies.
- VusionGroup, a French company who is the leader in smart digital labels and retail Internet of Things.
Kapsch, Austian company developing and selling products, systems and services primarily for electronic toll collection systems.
