The integrated system simultaneously collects and stores solar thermal energy with low losses under all conditions, providing 24/7 power.
Researchers at the University of Houston have designed a device that can efficiently capture and store solar energy for use in Internet of Things (IoT) and Industrial IoT applications. Unlike solar panels and solar cells that use photovoltaic technology to generate electricity directly, this hybrid device exploits the physical properties of molecular energy and the accumulation of latent heat, making energy harvesting and storage a 24/7 process, addressing a major drawback currently. of solar products.
The researchers synthesized the device using norbornadiene tetracycloalkane (NBD-QC) as a molecular storage material (MSM), which was separated from a localized phase change material (L-PCM). Silica aerogel to maintain the necessary difference in operating temperature.
A common method of storing solar energy is to use batteries and photovoltaic systems in small and large installations. It's not just electricity that needs to be stored: an equally useful aspect of energy conversion is the ability to capture and store solar thermal energy. However, this goal is not easy to achieve, especially if you need a system that can keep warm for long periods of time.
In recent years, this challenge has inspired new research directions, working to create solar energy storage on demand. The key point for these systems remains efficiency. Therefore, the development of the Houston researchers may drive decisive changes in the field of thermal batteries.
Efficient collection and storage of solar thermal energy is critical to harnessing the abundant solar radiation reaching the Earth's surface. Today's systems use expensive materials with high optical concentrations, which result in high heat losses.
The new device is based on a hybrid mode that uses daytime thermal positioning to provide 73% collection efficiency in small areas and about 90% collection efficiency in large areas. Especially at night, the energy stored by the hybrid system is recovered with 80% efficiency and warmer than during the day, which sets it apart from other state-of-the-art systems. Researchers in the December issue of the journal Joule.
Classical silicon photovoltaic systems are considered a mature technology and are approaching their theoretical performance limits, although incremental improvements are still being made. Currently, there is interest in double-sided panels, which harvest energy not only from the sun, but also indirectly from albedo—the light reflected by rocks, asphalt, or other surfaces.
However, a lingering disadvantage of renewable energy sources such as solar and wind power is their intermittent nature, which requires the use of batteries to safely and economically store the electricity generated so that it can be used when needed. Researchers at the University of Houston say their approach removes barriers to large-scale solar adoption by enabling 24/7 access to solar energy in all seasons and in all weather conditions (Figures 1 and 2).
Figure 1: Chemical structure of the University of Houston researchers' hybrid system (Image: "Full Spectrum Solar Thermal Energy HarvesTIng and Storage by a Molecular and Phase-Change Hybrid Material", Joule, Vol. 3, Issue 12)
Figure 2: Schematic of the new system (Image: "Full Spectrum Solar Thermal Energy Harvesting and Storage for Molecular and Phase Change Hybrid Materials", Joul e, Vol. 3, Issue 12)
"Part of the reason for the efficient harvesting is the device's ability to capture the full spectrum of sunlight, harvest it for immediate use and convert the excess energy into molecular energy storage," said Hadi Ghasemi, Bill D. Cook Associate Professor of Mechanical Engineering at the University, and the thesis Corresponding Author.
The integrated system also reduces heat loss, as there is no need to transmit the stored energy through long pipes.
Given other developments to achieve energy security and combat climate change, technologies to store solar energy at low cost and with high efficiency are a key focus.
For example, AI can regulate and optimize flow in smart grid applications to compensate for the intermittency of solar and wind power generation and minimize the need to compensate for grid imbalances in thermal power plants.
Reviewing Editor: Tang Zihong