Researchers have set a new efficiency world record for converting sunlight into electricity using transparent solar cells.
The breakthrough, made by an international team from the CitySolar project, is a huge boost for renewable energy, allowing entire skyscrapers to serve as power stations by transforming their windows into solar panels.
By combining organic solar cells with the so-called “miracle material” perovskite, the scientists were able to achieve an efficiency of 12.3 per cent – close to that of commercial solar cells.
“Transparent solar cells could be the next big step in building integrated energy solutions,” said Professor Morten Madsen from the University of Southern Denmark, who was one of the key researchers behind the breakthrough.
“The large glass facades found in modern office buildings can now be used for energy production without requiring additional space or special structural changes... This represents a massive market opportunity.”
The CitySolar project is the first to overcome the main challenge with transparent solar cells, which has been the balancing of efficiency and transparency.
The combination of perovskite with an organic layer allows the cell to harvest electricity from near-infrared and near-ultraviolet light, leaving light from the visible spectrum to pass through.
The two materials are also highly affordable, according to Professor Madsen, making it a suitable technology for commercial-scale deployment.
The project is currently at a Technology Readiness Level (TRL) of between five and six, meaning it is between the proof-of-concept and prototype stages.
It has already received nearly €4m (£3.3m) in funding from the EU in the hope that it will help Europe reach its target of fully decarbonising the building sector, which accounts for approximately 40 per cent of the continent’s energy consumption.
The team behind the discovery is currently in discussions with industry partners to scale up production of the see-through solar panels and make them available for future construction projects.
“There are still research improvements to be made but importantly, we know where the challenges lie and have a clear strategy for overcoming them,” said Professor Madsen. “We can scale up what we have, but we need business partners.”
