A fundamental challenge in energy sustainability is efficient utilization of solar energy towards energy‐neutral systems. The current solar cell technologies have been most widely employed to achieve this goal, but are limited to a single‐layer 2D surface. To harvest solar light more efficiently, a multilayer system capable of harvesting solar light in a cuboid through transparent photothermal thin films of iron oxide and a porphyrin compound is developed. Analogous to a multilayer capacitor, an array of transparent, spectral selective, photothermal thin films allows white light to penetrate them, not only collecting photon energy in a 3D space, but generating sufficient heat on each layer with significantly increased total surface area. In this fashion, thermal energy is generated via a multilayer photothermal system that functions as an efficient solar collector, energy converter and generator with high energy density. A solar‐activated thermal energy generator that can produce heat without any power supply and reach a maximum temperature of 76.1 °C is constructed. With a constant incoming white light (0.4 W cm−2), the thermal energy generated can be amplified 12‐fold via multilayers. The multilayer system extends another dimension in solar harvesting and paves a new path to energy generation for the energy‐neutral system.
This content will become publicly available on March 1, 2025
A photothermal solar tunnel via multiple transparent Fe3O4@Cu2-xS thin films for heating utility application
A Photothermal Solar Tunnel Radiator (PSTR) is designed and developed by employing multiple transparent photothermal glass panels (TPGP). The primary objective is to pioneer a transformative approach to achieve energy-neutral building heating utilities, exemplified by a lab-scale "Photothermal Solar Box" (PSB) exclusively heated with TPGP under natural sunlight. The PSTR presents a novel paradigm for sustainable energy, enabling direct solar energy capture through transparent glass substrates with photothermal coatings. The high transparency of Fe3O4@Cu2-xS coated glass substrates enhance efficient solar harvesting and photothermal energy generation within the Photothermal Solar Box. The system demonstrates an impressive thermal energy output, reaching up to 9.1x105 joules with 8 photothermal panels in parallel. Even under colder conditions (ambient temperature: -10 °C), with accelerated heat loss, the interior temperatures of the PSB with partial thermal insulation achieve a commendable 35 °C, showcasing effective photothermal heating in cold weather. These findings indicate the system's resilience and efficiency in harnessing solar energy under diverse conditions, including partial cloudy weather. The initiative contributes to broader sustainability goals by providing a scalable and practical alternative to traditional solar heating methods, aligning with the global mission for a cleaner, greener future.
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- Award ID(s):
- 1953009
- NSF-PAR ID:
- 10503538
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Solar Energy
- Volume:
- 271
- Issue:
- C
- ISSN:
- 0038-092X
- Page Range / eLocation ID:
- 112444
- Subject(s) / Keyword(s):
- 3D solar harvesting, spectral selective films, energy-neutral, photothermal energy generation, transparent multi-panels
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Solar near-infrared (NIR) selective glazing systems have been proposed by incorporating photothermal effects (PTE) of a nanoparticle film into building windows. From an energy efficiency perspective, the nanoscale PTE forms unique inward-flowing heat by heating up the window interior surface temperature under solar near-infrared, significantly improving the window thermal performance. Also, the PTE-driven solar heat gains are dynamic upon solar radiation and weather conditions. However, the PTE on annual building energy use has not been investigated thoroughly, due to the lack of an accurate and appropriate energy simulation method. In this study, we used the EnergyPlus energy management system to develop a parametric energy model and simulation approach in which a solar-temperature-dependent thermal model was embedded into the parametric energy simulation workflow. Applying this method, we examined the solar near-infrared-dependent PTE-induced thermal performances of glazing systems and their effects on annual heating energy use in representative cold climates (i.e., Zones 4, 5, and 6). The results show that the dynamic model considering the PTE demonstrated more heating energy savings, up to 11.64% in cold climates, as opposed to the baseline model that ignored the PTE. This work presents a method to model and simulate the dynamic thermal performance of windows with PTE.more » « less
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The efficiencies of photovoltaic (PV) and thermoelectric (TE) have been limited by the intrinsic properties to ~ 25 % and ~ 10 %, respectively. In current applications, photovoltaics utilizes the shorter wavelength end of the solar spectrum but suffer decreases in efficiency from heating caused by IR absorption. The novel tunable nanostructures of new hybrids eliminate this problem by directing thermal energy from longer wavelengths to the thermoelectric device. Solar light is harvested through transparent hybrid and segregated into different wavelengths: the IR is absorbed by the hybrid which is photothermally heated up to ~100 °C for the required thermoelectric temperature span; the UV/visible is directed to PV with reduced IR components, therefore significantly reducing heating. In this way, both PV and TE operate jointly by separately utilizing the full spectrum of solar light. The novel hybrid functions not only as a photothermal heater for TE but also a wavelength segregator enabling the PV and TE devices to synergistically produce electrical energy with much greater system efficiency. Also identified is the operating structural mechanism on spectral tunability and photothermal effect of the photonic hybrids.more » « less
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