05/29/2026
Scandinavia is doing exciting things with solar including this project.
Denmark has installed transparent photovoltaic solar windows on Copenhagen skyscrapers generating electricity from every building facade.
The Nordhavn Solar Facades project retrofits 24 Copenhagen commercial towers with Onyx Solar perovskite-silicon tandem transparent photovoltaic glass units achieving 14 percent power conversion efficiency while maintaining 40 percent visible light transmission. Each tower's south facade generates 80 to 150 kilowatts annually, collectively producing 2.4 megawatts across 18,000 square metres of glazed facade area.
Building-integrated photovoltaic glass eliminates the roof space competition between solar panels and green rooftops, mechanical plant, and architectural features that limits conventional solar deployment in dense urban environments. At Copenhagen's latitude south building facades receive 60 percent of rooftop solar irradiance — sufficient to make transparent facade solar economically attractive at current perovskite panel manufacturing costs.
Denmark's Energy Agency has approved building-integrated solar requirements for all new commercial construction above 5,000 square metres from 2027, projecting 150 megawatts of facade-integrated solar capacity across Danish urban centres by 2035. The regulation makes Denmark the first country to mandate building-integrated photovoltaic facades as a standard component of large commercial construction.
Source: Onyx Solar Denmark, Danish Energy Agency, Joule, 2025