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Why and how

Heat management
in the built environment

More than one third of the total annual energy consumption in the EU is related to the built environment. To reach our climate goals and realize a sustainable, climate neutral built environment, we need to reduce energy consumption and increase on-site green energy generation.

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A major contributor to a building’s energy consumption are windows. They represent the most vulnerable part of the building skin for radiator heat loss and are also responsible for elevated room temperatures in summer due to solar heat transmission. Even though energy-efficient glazing can have a big impact on a building’s energy consumption, it is either optimized to reduce radiator heat loss or to prevent solar heat transmission. Since in intermediate climates both types of energy loss are equally important, we develop within project SUNOVATE a new type of energy-efficient smart window, that autonomously changes its solar heat blocking properties at a pre-defined temperature. Hereby the new technology enables the use of solar heat to heat up a building in winter, which in combination with reduced radiator heat loss reduces heating demand. Simultaneously, the technology enables the blocking of solar heat from entering a building in summer, which keeps the room temperature low and reduces cooling demand.


For on-site energy generation, building integrated photovoltaics (BIPV) are a popular and promising solution. BIPV combines solar energy harvesting at high power output with design elements that fit perfectly into a building’s roof and/or façade. Hereby the aesthetics and acceptability are improved but also the application area of solar panels is broadened. Since for BIPV, solar panels are integrated into the building skin, they suffer more than standard solar panels from overheating. This can lead to reduced power output, but also to a reduced lifetime. To solve this problem, we develop within project SUNOVATE heat blocking solar panels with increased power output and lifetime. The pigmented encapsulants within the solar panels block infrared radiation without impacting the part of the solar spectrum that can be harvested by crystalline silicon PV. This reduces overheating of BIPV and hereby increases annual power output and the solar panels lifetime.