12,000 colored solar glass panels make up the facade of the Copenhagen International School, Denmark, and produce 50 percent of the energy needed to run the building.

The facade of the Copenhagen International School, Denmark, is secured by 12,000 solar glass panels, making it the world's biggest solar facade. The panels can deliver 300 MW long periods of electricity every year, meeting half the energy needs of the school.

The panels are hued by light

Other than being an efficient energy solution, the solar facade has redefined the style of the building, transforming it into an architectural work. The shade of the solar glass panels is sea green, the same as Copenhagen's symbol: Andersen' mermaid, which welcomes tourists in the Danish capital. The special sea-green hue of the panels was made by the Ecole Polytechnique Federale in Lausanne (EPFL) after over a time of development.

Photo by Simone Hutsch / Unsplash

By utilizing the process of light interference, the researchers achieved the solar glass panels' distinctive color. This impact can be seen in soap bubbles, in the wings of some butterflies and the layer of oil on a water surface.  “The iris effect creates a colorful rainbow on a very thin layer. We used the same principle and adapted for glass,” said Jean-Louis Scartezzini, the head of the Solar Energy and Building Physics Laboratory (LESO-PB).

The process is just simple, as controlling the light reflected by solar panels to produce one single shading without diminishing the energy efficiency is rather challenging. In reality, it took 12 years of research to understand the panels. The researchers created special filters that figure out which wavelengths of light will be reflected as visible shading, while the remainder of the sunlight is consumed by the solar panel and converted into energy. Without utilizing any pigments, however guaranteeing that only certain wavelengths are reflected, the solar panels are brick red, royal blue, golden yellow or sea green.

Building renovation for energy effectiveness

Photo by Alexander Abero / Unsplash

Old buildings, built at a time when energy effectiveness wasn't much considered, are a robust part of Europe's heritage, and their renovation is a continuously debated issue all over Europe.

On average, the renovation rate of EU buildings is around 1 percent for each year. This implies it would take 100 years to renovate all European old buildings. To accelerate this process, which would have positive effects in terms of energy proficiency, environment protection and better health for citizens, the European Union has launched the Climate-KIC initiative. The purpose is linking colleges and companies to promote innovative technologies in the energy efficiency field and make building materials that permit decarbonizing buildings.