Resumen de Advanced thermal energy storage and management solutions towards low-carbon buildings. Materials, applications and decision support strategies
This thesis focuses on the development of advanced thermal energy storage and management solutions towards low-carbon buildings, with a high degree of technical, economic and social viability, and great potential for implementation in retrofitting actions. It involves the knowledge, study and achievement of advanced materials for efficient thermal storage, with long-term stability and reliability and competitive cost; advanced solutions for seasonal storage in large-scale applications for cost-effective low-carbon district networks; and novel thermal storage technologies in small-scale applications for cost-optimal implementation of low-carbon heating and cooling technologies, such as efficient heat pumps. The research contributions are divided into three chapters. In the first chapter, decision support criteria for competitive low-carbon solutions are analysed by identifying the main environmental, economic and social requirements demanded by each stakeholder involved in energy retrofitting. Then, the best available energy efficiency solutions are highlighted, and optimisation procedures to improve the accuracy in energy assessment are proposed, analysed and discussed. In the second chapter, the best available thermal energy storage materials are identified and validated for low-to-moderate temperature applications. Available materials and experimentally tested compounds are characterised and compared, according to their thermophysical properties and costs, with the aim of identifying advantages, drawbacks and challenges for their application and commercialisation. The results highlight the best available materials for low-carbon applications, which are further studied through numerical validation in the following chapter, and the most promising compound is experimentally tested and validated for use as an advanced storage material. In the last chapter, the most reliable thermal energy storage applications for buildings are identified, characterised and numerically evaluated. Existing and tested applications are compared, according to their economic and environmental performance, and the best alternatives are further developed and studied through numerical simulation as follows. The potential of solar district networks with borehole thermal energy storage are validated and compared with other renewable technologies. The effectiveness of latent heat storage for passive cooling is analysed and proven through parametric analysis. An innovative smart building integration for energy flexibility in heating, based on latent heat storage and smart demand response, is developed and numerically demonstrated. In addition, a novel compact unit is designed and validated for the effective implementation of passive cooling and energy flexibility for low-carbon buildings. Furthermore, key factors, requirements and design criteria, for their optimal implementation, are provided.
