Smart windows improve the energy efficiency of buildings

Smart windows improve the energy efficiency of buildings (Picture)

Besides liquid crystals for displays such as televisions, monitors and tablets, Merck KGaA, Darmstadt, Germany, is also developing liquid crystals for new applications. For instance, we are working with architects, glass makers and facade manufacturers to create the windows of tomorrow. Our ambitious goal is to utilize smart windows to make buildings more energy-efficient. The idea behind these windows is that their properties can be modified at the touch of a button. They can be tinted darker or made more transparent depending on environmental conditions such as the season or the time of day, thereby allowing more or less light and/or warmth to enter the building. The windows thus help regulate the temperature in interior spaces; in winter, more light is let in, and in summer less.

Our smart energy glass technology is based on liquid crystal mixtures containing tailor-made rod-shaped dyes. When a small electric field is applied, the dye-doped liquid crystals change their orientation to absorb either more or less light. This makes it possible to control the transparency of the glass as desired. Within seconds, the window can be switched from a bright, transparent state to a defined colored, dark state. These windows boost the energy efficiency of buildings since they reduce HVAC costs. To protect people in buildings from glaring sunlight, it is also possible to adjust the window’s level of tinting individually. The advantage here over external blinds is that the window is not completely darkened nor the outside view blocked. Consequently, lights need not be turned on during the day, and employees can still look out of their windows, resulting in a pleasant work environment.

Our smart energy glass technology can also make the windows self-powering. Part of the light absorbed by the dyes is channeled to the glass edges, where solar cells embedded in the frames convert it into electricity to power the windows. Merck KGaA, Darmstadt, Germany is collaborating with the Dutch company Peer+ to develop this concept. The first set of pilot projects were initiated in the Netherlands in 2013 and have proven successful. These windows will also be installed in the innovation center under construction at Merck KGaA, Darmstadt, Germany headquarters in Darmstadt, which is scheduled for completion by the end of 2014.

Our smart energy glass technology boosts the energy efficiency of buildings, conserves energy, and increases people's sense of well-being – a sustainable and innovative solution for the future.


Publication of Merck KGaA, Darmstadt, Germany.

In the United States and Canada the subsidiaries of Merck KGaA, Darmstadt, Germany operate under the umbrella brand EMD.


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