A recent breakthrough in transparent solar panels could seamlessly integrate clean energy into building design by transforming ordinary windows into power generators.
An international team of researchers at CITYSOLAR recently announced an efficiency record for transparent solar cells. The panels combine organic solar cells with perovskites to achieve an efficiency of 12.3%, moving closer to the average 21% efficiency of non-transparent panels.
“We are the first to achieve this with complete semi-transparency in a large area,” said team member Jessica Barichello, a post-doctoral researcher at the Centre for Hybrid and Organic Solar Energy in Rome.
Barichello told The Energy Mix the researchers used a Bragg reflector—“a multilayer optical structure designed to reflect specific wavelengths of light while allowing others to pass through”—to improve efficiency. The reflector helped to increase density without significantly compromising transparency.
Transparent solar panels are meant to replace windows on commercial buildings for integrated electricity generation. CITYSOLAR has received €4 million (C$6.2 million) from the European Union for its efforts toward decarbonizing the building sector, which accounts for 40% of the bloc’s carbon dioxide emissions, reports The Independent.
“The large glass facades found in modern office buildings can now be used for energy production without requiring additional space or special structural changes,” said Prof. Morten Madsen, another CITYSOLAR researcher, from the University of Southern Denmark. “This represents a massive market opportunity.”
CITYSOLAR’s panels are between a technology readiness level of five and six, meaning they’ve been proven in a lab but without a developed prototype. They are not yet ready for real-world application.
Barichello said the panels are undergoing thermal and light stress tests, but initial life cycle assessments suggest they offer “environmental advantages compared to silicon cells.”
However, tests have not yet compared the modules’ performance as windows—including their lifespan and insulative properties—with the non-solar-photovoltaic commercial windows currently used on office buildings and skyscrapers. Commercial windows typically last from 15 to 30 years.
Barichello said the panels could also be used for agrivoltaics.
“With its high transparency, our demonstrator presents a potential solution for agrivoltaic systems, enabling sufficient light penetration for crops while simultaneously producing energy to meet a portion of energy needs,” she told The Mix.
This article first appeared in The Energy Mix, and is republished under a Creative Commons License.
