Periodic Reporting for period 1 - MIRACLE (Photonic Metaconcrete with Infrared RAdiative Cooling capacity for Large Energy savings)
Reporting period: 2021-02-01 to 2022-07-31
Photonics has a broad range of applications, gradually also conquering the construction industry. The development of multi-functional concrete with improved traditional properties and novel functionalities is key for sustainable and high-performance solutions. The EU funded MIRACLE project envisions a new science and technology that turns low-tech concrete and cement-based materials into high-tech eco-friendly photonic metamaterials. In particular, the MIRACLE project aims to construct and test a revolutionary Photonic Meta-Concrete (PMC) whose response to light will be engineered for exhibiting radiative cooling ability; i.e. the PMC will be able to expel heat from buildings to the outer space without any extra energy consumption.
For this to happen, the photonic properties must be engineered for efficiently scattering sun-light while focusing the emissivity in the Atmospheric Window (a narrow spectral region centred at light wavelengths of 10 microns where the atmosphere is transparent). To this end, MIRACLE project is revisiting the concept of concrete at a threefold level.
• The most appropriated chemical ingredients must be chosen in view of their photonic response.
• The hierarchical porous cementitious structure must be carefully tuned to enhance the light scattering.
• The last stage corresponds to the inclusion of microfibres or microstructures in a regular fashion so as to truly form a PMC with radiative cooling performance in daytime applications.
In the context of an increasing global warming this scientific and technologic breakthrough can have a huge impact in the Nearly-Zero-Energy-Buildings (NZEB) uptake and in the global strategy for reducing the CO2 footprint. Moreover, its applications can also be expanded in multiple fields such as solar cell technology or communication technologies.
Overall, the MIRACLE project endeavours to
(1) prove the feasibility of this breakthrough idea by developing for the first time in the state of the art a radiative cooling device based on a PMC,
(2) fabricate a prototype whose radiative cooling performance will be validated on the roof of a real building and
(3) start the roadmap of this emerging S&T avenue (PMC) by evaluating its potential environmental impact and exploring how the PMCs could be used in other applications.
For this to happen, the photonic properties must be engineered for efficiently scattering sun-light while focusing the emissivity in the Atmospheric Window (a narrow spectral region centred at light wavelengths of 10 microns where the atmosphere is transparent). To this end, MIRACLE project is revisiting the concept of concrete at a threefold level.
• The most appropriated chemical ingredients must be chosen in view of their photonic response.
• The hierarchical porous cementitious structure must be carefully tuned to enhance the light scattering.
• The last stage corresponds to the inclusion of microfibres or microstructures in a regular fashion so as to truly form a PMC with radiative cooling performance in daytime applications.
In the context of an increasing global warming this scientific and technologic breakthrough can have a huge impact in the Nearly-Zero-Energy-Buildings (NZEB) uptake and in the global strategy for reducing the CO2 footprint. Moreover, its applications can also be expanded in multiple fields such as solar cell technology or communication technologies.
Overall, the MIRACLE project endeavours to
(1) prove the feasibility of this breakthrough idea by developing for the first time in the state of the art a radiative cooling device based on a PMC,
(2) fabricate a prototype whose radiative cooling performance will be validated on the roof of a real building and
(3) start the roadmap of this emerging S&T avenue (PMC) by evaluating its potential environmental impact and exploring how the PMCs could be used in other applications.
The present project status is highly encouraging. We have undertaken a comprehensive study combining simulations and experiments which have enabled a deep scrutiny of the photonic response of most of the phases appearing in cementitious composites. Unlike the few existing works dealing with 3D concrete materials, which have explored the radiative properties of regular concretes, our study has revealed that typical concrete compositions could be drastically optimized. In fact, we have obtained a clear picture about which chemical composition is optimal, along with a portfolio of plausible combinations.
It is remarkable that, in parallel, we have made a significant step forward in the establishment of linkages between cementitious microstructure with their photonic properties, something totally novel in the state of the art. Starting from theoretical models capable of estimating the effective response of porous cementitious matrices, our experiments in the laboratory have confirmed the great potentiality offered by the “pore network engineering”.
Likewise, multiple geometrical set-ups for the arrangements of microfibres have been computationally tested for the design of PCMS, demonstrating a substantial improvement of the cooling power in comparison to the plain concretes, and effectively guiding the design of the 3D printed molds.
Finally, our preliminary Life Cycle Analysis (LCA) has confirmed our prediction and the PCM can be extremely attractive from an environmental point of view while a modelling study (combining chemical kinetics, molecular mechanics and electromagnetic simulations), has proved that the use of concrete can reduce the operating temperature of solar cells by up to 20 K, with outstanding efficiency and lifetime gains.
It is remarkable that, in parallel, we have made a significant step forward in the establishment of linkages between cementitious microstructure with their photonic properties, something totally novel in the state of the art. Starting from theoretical models capable of estimating the effective response of porous cementitious matrices, our experiments in the laboratory have confirmed the great potentiality offered by the “pore network engineering”.
Likewise, multiple geometrical set-ups for the arrangements of microfibres have been computationally tested for the design of PCMS, demonstrating a substantial improvement of the cooling power in comparison to the plain concretes, and effectively guiding the design of the 3D printed molds.
Finally, our preliminary Life Cycle Analysis (LCA) has confirmed our prediction and the PCM can be extremely attractive from an environmental point of view while a modelling study (combining chemical kinetics, molecular mechanics and electromagnetic simulations), has proved that the use of concrete can reduce the operating temperature of solar cells by up to 20 K, with outstanding efficiency and lifetime gains.
So far, radiative cooling technology has attracted wide interest from both fundamental and applied sciences, due to its a priori potential in multiple applications like building cooling, renewable energy harvesting, or even dew water production. However, currently the development of this technology is in a bottleneck, where the scientific progress has been largely based on either (i) fanciful 1D and 2D photonic metamaterials containing scarce and expensive materials with negligible potential impact in any real-world energy solution; or (ii) hierarchically porous polymer coatings which can be scalable, but at the cost of expensive industrial manufacturing processes, sacrificing spectral selectivity performance and suffering unavoidable durability issues (e.g. ultraviolet UV degradation).
In this context, the MIRACLE project explores the idea of transforming reinforced cement-based materials into the “ultimate composites” for radiative cooling. Our educated feeling is that concrete, when properly tuned, can be the “win-win combination” of the aforementioned innovations based on photonic metamaterials and hierarchical porous systems. In fact, MIRACLE aims at revolutionizing the technology of radiative materials by fabricating for the first time a cheap, affordable and scalable radiative cooling device based on steel reinforced concrete that functions as a true Photonic Meta-Concrete (PMC). The evidences and results obtained so far confirm our idea.
Our educated guesses at the beginning of the project have turned out to be certainties. The lab-scale findings tell us that the proof of concept of the PCM would be attainable soon, and the MIRACLE project ambition is to demonstrate the practical feasibility of this technology in a realistic scenario. In fact, one of the most important goals of the project is the fabrication of a prototype whose radiative cooling performance will be validated on the roof of a real building. This project milestone will be the definitive kick-off of the advent of the PMC and all the associated benefits:
From an environmental point of view the PMCs can make a significant step in the progress towards Nearly-Zero-Energy-Buildings (NZEB) uptake. Moreover, the PCMs can help in palliating the Urban Heat Island Effect (UHI). Urban and metropolitan areas are significantly warmer than its surrounding rural areas due to human activities. This involves multiple harmful environmental consequences.. Moreover, the UHI effect directly influences the health and welfare of urban residents. Indeed, it is well documented there is an increase of the mortality rate during heat waves in hot urban areas, when heat is trapped and deprives urban residents of the cool relief during the night
Finally, and concomitant to the design of optimized PMCs, new products (microfibers, new micro-nano particles, concrete foams, new cement formulations, new supplementary cementitious materials…) can emerge from the project, with their corresponding niche markets. One relevant example is, of course, the one high-tech 3D printing SMEs, where the new micro-patterned molds for casting the PMC can give them a huge market, just in view of the massive employment of concrete.
In this context, the MIRACLE project explores the idea of transforming reinforced cement-based materials into the “ultimate composites” for radiative cooling. Our educated feeling is that concrete, when properly tuned, can be the “win-win combination” of the aforementioned innovations based on photonic metamaterials and hierarchical porous systems. In fact, MIRACLE aims at revolutionizing the technology of radiative materials by fabricating for the first time a cheap, affordable and scalable radiative cooling device based on steel reinforced concrete that functions as a true Photonic Meta-Concrete (PMC). The evidences and results obtained so far confirm our idea.
Our educated guesses at the beginning of the project have turned out to be certainties. The lab-scale findings tell us that the proof of concept of the PCM would be attainable soon, and the MIRACLE project ambition is to demonstrate the practical feasibility of this technology in a realistic scenario. In fact, one of the most important goals of the project is the fabrication of a prototype whose radiative cooling performance will be validated on the roof of a real building. This project milestone will be the definitive kick-off of the advent of the PMC and all the associated benefits:
From an environmental point of view the PMCs can make a significant step in the progress towards Nearly-Zero-Energy-Buildings (NZEB) uptake. Moreover, the PCMs can help in palliating the Urban Heat Island Effect (UHI). Urban and metropolitan areas are significantly warmer than its surrounding rural areas due to human activities. This involves multiple harmful environmental consequences.. Moreover, the UHI effect directly influences the health and welfare of urban residents. Indeed, it is well documented there is an increase of the mortality rate during heat waves in hot urban areas, when heat is trapped and deprives urban residents of the cool relief during the night
Finally, and concomitant to the design of optimized PMCs, new products (microfibers, new micro-nano particles, concrete foams, new cement formulations, new supplementary cementitious materials…) can emerge from the project, with their corresponding niche markets. One relevant example is, of course, the one high-tech 3D printing SMEs, where the new micro-patterned molds for casting the PMC can give them a huge market, just in view of the massive employment of concrete.