Radiative cooling technology harnesses a unique natural phenomenon: the Earth’s ability to dissipate heat through the atmospheric transparency window (8–13 μm), also known as the Atmospheric Window (AW). This passive cooling mechanism enables terrestrial bodies to emit infrared radiation directly into outer space, thereby maintaining thermal balance without external energy input. The concept underpins a new generation of sustainable materials capable of counteracting the rising energy demand associated with air conditioning and refrigeration in modern cities.
Radiative cooling materials have gained widespread attention due to their versatility across multiple applications, including building envelopes, renewable energy systems, and dew water harvesting. Among these, their role in reducing building energy consumption is particularly critical, as the built environment currently accounts for over 40% of global energy demand, with cooling systems representing the largest share. In rapidly urbanizing regions such as East Asia, more than half of electricity consumption is devoted to maintaining indoor comfort. Therefore, the development of advanced, scalable, and cost-effective cooling materials could play a transformative role in global energy transition efforts.
Historically, “cool-roof” coatings based on polymer films with TiO2 pigments have offered moderate improvements, achieving solar reflectance values around 0.85 and high emissivity (≈0.95) within the AW. While these solutions can reduce surface temperatures by 20–30 °C, they remain limited in durability, scalability, and spectral control. More sophisticated photonic metamaterials and porous polymeric structures have emerged, yet these often rely on costly raw materials or energy-intensive fabrication processes.
Amid this technological landscape, the MIRACLE project introduced a breakthrough by integrating radiative cooling principles directly into cementitious materials. Through extensive multidisciplinary research, the project established the chemical and microstructural foundations for Daytime Radiative Cooling Cementitious Composites (DRCCCs)—a new class of concretes capable of operating below ambient temperature under direct sunlight. The COOLCRETE initiative now builds on this foundation, aiming to accelerate the path from laboratory discovery to commercial application.
The proposal pursues three key objectives:
- O1: Assess the integration of DRCCC technology with existing cooling systems, such as heat pumps and thermal energy storage devices.
- O2: Evaluate geoclimatic relevance, quantify energy performance, and assess environmental and economic impacts across regions and building types.
- O3: Identify target markets, potential clients, and commercialization routes, paving the way for the creation of a dedicated spin-off company by early 2025.
