A revolutionary breakthrough in solar energy technology could help Europe meet its climate goals. Danish researchers have developed transparent solar cells that can turn skyscraper windows into power generators.
The innovation, led by the CitySolar project at the University of Southern Denmark, has set a new world record for solar efficiency in transparent panels. By combining organic solar cells with perovskite, researchers achieved an efficiency of 12.3 per cent, comparable to traditional solar panels. Additionally, the panels offer 30 per cent transparency, making them suitable for use in modern glass buildings.
Transparent solar technology has long struggled to balance energy generation with visibility. Previous designs lacked efficiency or were too opaque for practical use. However, CitySolar has overcome these challenges, presenting a viable solution for integrating renewable energy into urban infrastructure.
Professor Morten Madsen, a key researcher in the project, emphasised the potential impact of the technology. “The large glass facades in modern office buildings can now generate energy without taking up extra space,” he said. He also highlighted that the materials used are affordable and scalable for commercial deployment.
The tandem solar cells absorb infrared and ultraviolet light while allowing visible light to pass through, maintaining clarity. Currently at a Technology Readiness Level of five to six, the project is transitioning from proof-of-concept to prototype stages.
With nearly €4 million in EU funding, CitySolar is now engaging with industry partners to scale up production. This breakthrough could play a crucial role in Europe’s goal to make all new buildings nearly zero energy by 2050.
