The results of the MIRACLE project have been highly encouraging. We conducted a comprehensive study combining simulations and experiments, enabling an in-depth analysis of the photonic response of various phases found in cementitious composites. Unlike the limited existing work on 3D concrete materials—mostly focused on conventional formulations—our research has shown that typical concrete compositions can be drastically optimized for radiative cooling.
We have developed several concrete designs capable of daytime radiative cooling; these prototypes consistently maintained temperatures significantly below ambient levels, even under direct sunlight on hot summer days. Photonic performance was on par with the best state-of-the-art cooling materials. These results were validated through extended outdoor experiments on the roof of the KUBIK building, where our materials outperformed both standard concretes and those coated with commercial cool paints. Moreover, MIRACLE concretes exhibit these remarkable radiative cooling properties while maintaining a very low environmental impact, as demonstrated in a benchmarking study comparing their life-cycle assessment (LCA) with other leading radiative cooling solutions.
In addition, we evaluated the environmental impact of our PMCs. Notably:
We demonstrated that our PCMs can lead to substantial energy savings in buildings—up to 70% in cooling energy for a typical mid-rise building, depending on the climate.
Our models predict that using our PCMs could significantly mitigate the Urban Heat Island Effect, with potential city-wide temperature reductions of up to 10°C during heatwaves.
Furthermore, our studies revealed that integrating our PCMs can lower the operating temperature of solar cells by as much as 20 K, resulting in enhanced efficiency and lifespan.
The intense research effort has yielded numerous scientific publications—35 accepted to date, with more forthcoming. MIRACLE’s impact has also been recognized internationally with a couple of conference awards.
We have also organized two international workshops, which served as valuable platforms to present our progress and engage with key stakeholders including scientists, industry professionals, and policymakers.
Finally, we’ve placed a strong emphasis on translating our research into practical, market-ready solutions. In addition to participating in numerous industrial fairs, we have secured two patents for our most promising technologies. To support commercialization, we launched a spin-off company, PhotoKrete S.L. which aims to accelerate the deployment of our patented PCMs.
