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1. Emphasizing Electro-Thermal Dynamics for Design, Modeling, and Control of Microgrids

   https://doi.org/10.1109/ACCESS.2025.3593387  

   Ouedraogo, Asmaou S; Docimo, Donald J (July 2025, IEEE Access)

   This article studies the design, modeling, and control of microgrid systems with the inclusion of internal electro-thermal dynamics. Microgrids play a vital role in integrating renewable energy and enabling distributed energy systems. However, their complexity arising from diverse and dynamic components necessitates advanced control strategies. While existing works often utilize model-based controllers, the focus is primarily on electrical dynamics, with limited attention to the thermal behavior of components. The intricate interplay between electrical and thermal power terms heavily impacts component behavior, exemplified by the dependency of photovoltaic (PV) module electricity production on temperature. This article addresses the limited studies on electro-thermal microgrid dynamics through three contributions. First, a candidate microgrid design is developed to utilize electro-thermal knowledge, incorporating active cooling for PVs. Second, a graph-based modeling methodology is expanded to represent microgrid component- and system-level dynamics. Third, a hierarchical control framework is developed to define controllers for microgrids using the graphical model. Controllers produced from the framework enable management of electro-thermal behavior while adhering to battery charge limits. Case studies utilizing realistic environmental data are explored to evaluate the performance of the proposed system. Results indicate design and model-based control that integrate electro-thermal dynamics provide improvements to energy generation and performance even under nonideal conditions. 

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2. Review of Dynamic Building Envelope Systems and Technologies Utilizing Renewable Energy Resources

   https://doi.org/10.3390/designs9020041  

   Almesbah, Mohammad; Wang, Julian (April 2025, Designs)

   Dynamic building envelopes integrated with renewable energy sources, termed Dynamic and Renewable Source Building Envelopes (DREBE), provide an innovative approach to optimizing building envelope designs. Yet, these systems are not mature enough and not widely adopted in the industry and few literature resources are employed to understand them. These systems dynamically respond and adapt to various environmental, energy, and occupancy demands for higher energy efficiency and comfort levels compared to traditional building envelopes while simultaneously producing energy. Their potential in climate change mitigation and fostering sustainable urban development warrants great attention from industry and urban planners. Especially in positive energy districts, which aim to reach net-positive energy goals through utilizing smart energy efficient building systems on the district level. This paper reviews innovative systems like dynamic photovoltaic shading devices and phase change materials and evaluates their performance by answering two research questions, what are the current DBE trends and are they feasible in achieving net-positive energy consumption? The analysis conducted reveals the dominance of solar-based dynamic renewable energy systems and a great need for alternatives. The study suggests that alternatives like wind as a renewable energy source should be studied with dynamic systems. Moreover, the study highlights current research gaps including insufficient data on long-term application and economic costs associated with such systems. To address this gap, the study suggests exploring in depth some of these systems and then branching into various combinations of dynamic envelope systems with multiple renewable or adaptive components to further enhance the overall building performance. By synthesizing the current body of literature, this paper gives insights into advancing the application of the dynamic building envelope systems and highlights their crucial role in the future of sustainable urban environments. 

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3. Multivalent Hygrothermal Material System for Double-Skin Envelope Dehumidification Cooling and Daylighting

   Ida, Aletheia (April 2018, Building Enclosure Science and Technology Conference)

   A unique paradox exists between the early and modern architectural and mechanical means of dealing with humidity in and around buildings. Traditional architectural conditions of biopolymeric thatch dwellings accommodated human thermal comfort through dehumidification by the materials employed at the building envelope. Original mechanical developments for dehumidification processes were developed specifically for removing moisture from materials in industrial applications. However, today, the modes by which humidity is treated for human comfort and material protection is inverted: buildings now utilize mechanical conditioning for dehumidification cooling functions and moisture protective materials in the building enclosure systems. Emerging multivalent hydrophilic materials are able to process humidity and moisture transport in new ways to allow for a systemic return to dehumidification cooling functions integrated in the building envelope system. The hydrophilic polymers are synthesized with low energy methods and poured into molds and then lyophilized to create macroporous networks that enhance both the sorption and thermal characteristics in the proposed application. The thermal and optical properties of novel hygrothermal materials are identified and used as inputs for simulation modeling for the proposed multivalent building enclosure system. The initial results provide improvements on annual energy loads and consumption for hot-humid climate conditions (Miami and Mumbai). The introduction of a sorption coefficient for the dehumidification function provides a unique contribution to design and performance analyses of double-skin envelopes. In addition, the dynamic modeling for temporal variations of material properties at the envelope also provides a new contribution to the field of building performance simulation. The challenges of these novel modes for moisture processing in the building envelope materials are addressed, with future work required for microbial identification and monitoring. The advantages from initial analytical and simulation modeling convey improvements for building energy conservation, natural daylighting, and water recuperation potential. 

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4. An Instance Segmentation and Clustering Model for Energy Audit Assessments in Built Environments: A Multi-Stage Approach

   https://doi.org/10.3390/s21134375  

   Arjoune, Youness; Peri, Sai; Sugunaraj, Niroop; Biswas, Avhishek; Sadhukhan, Debanjan; Ranganathan, Prakash (July 2021, Sensors)

   null (Ed.)

   Heat loss quantification (HLQ) is an essential step in improving a building’s thermal performance and optimizing its energy usage. While this problem is well-studied in the literature, most of the existing studies are either qualitative or minimally driven quantitative studies that rely on localized building envelope points and are, thus, not suitable for automated solutions in energy audit applications. This research work is an attempt to fill this gap of knowledge by utilizing intensive thermal data (on the order of 100,000 plus images) and constitutes a relatively new area of analysis in energy audit applications. Specifically, we demonstrate a novel process using deep-learning methods to segment more than 100,000 thermal images collected from an unmanned aerial system (UAS). To quantify the heat loss for a building envelope, multiple stages of computations need to be performed: object detection (using Mask-RCNN/Faster R-CNN), estimating the surface temperature (using two clustering methods), and finally calculating the overall heat transfer coefficient (e.g., the U-value). The proposed model was applied to eleven academic campuses across the state of North Dakota. The preliminary findings indicate that Mask R-CNN outperformed other instance segmentation models with an mIOU of 73% for facades, 55% for windows, 67% for roofs, 24% for doors, and 11% for HVACs. Two clustering methods, namely K-means and threshold-based clustering (TBC), were deployed to estimate surface temperatures with TBC providing consistent estimates across all times of the day over K-means. Our analysis demonstrated that thermal efficiency not only depended on the accurate acquisition of thermal images but also relied on other factors, such as the building geometry and seasonal weather parameters, such as the outside/inside building temperatures, wind, time of day, and indoor heating/cooling conditions. Finally, the resultant U-values of various building envelopes were compared with recommendations from the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) building standards. 

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5. Performance Modeling and Analysis of a Thermoelectric Building Envelope for Space Heating.

   Liu, X.; Qu, M.; Yazawa, K.; Kohanoff, J.; Chudzinski, P.; Stella, L.; Norton, B.; Holmes, N.; Jani, R.; Yin, H. (July 2022, 2022 (7th) International High Performance Buildings Conference)

   To provide energy-efficient space heating and cooling, a thermoelectric building envelope (TBE) embeds thermoelectric devices in building walls. The thermoelectric device in the building envelope can provide active heating and cooling without requiring refrigerant use and energy transport among subsystems. Thus, the TBE system is energy and environmentally friendly. A few studies experimentally investigated the TBE under limited operating conditions, and only simplified models for the commercial thermoelectric module (TEM) were developed to quantify its performance. A holistic approach to optimum system performance is needed for the optimal system design and operation. The study developed a holistic TBE-building system model in Modelica for system simulation and performance analysis. A theoretical model for a single TEM was first established based on energy conversion and thermoelectric principles. Subsequently, a TBE prototype model combining the TEM model was constructed. The prototype model employing a feedback controller was used in a whole building system simulation for a residential house. The system model computed the overall building energy efficiency and dynamic indoor conditions under varying operating conditions. Simulation results indicate the studied TBE system can meet a heating demand to maintain the desired room temperature at 20 °C when the lowest outdoor temperature is at -26.3 °C, with a seasonal heating COP near 1.1, demonstrating a better heating performance than electric heaters. It suggests a potential energy-efficient alternative to the traditional natural gas furnaces and electric heaters for space heating. 

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