DEMAND RESPONSE THROUGH TRANSACTIVE CONTROL OVER PERSONAL ENVIRONMENTAL CONTROL SYSTEMS

Abstract

The building sector consumes a significant amount of energy. The three major building performance areas are comfort, energy efficiency, and demand response capabilities. In the recent past, widespread penetration of Distributed Energy Resources (DER) have increased interest in using end-user devices and equipment in buildings as flexible devices to balance grid supply and demand, i.e., “Grid-Responsive” buildings. DER refer small-scale power generation or storage technologies that can be deployed close to the point of energy consumption. These resources are often decentralized and include renewable energy sources such as solar panels, wind turbines, and energy storage systems like batteries. Integrating DER introduces many operational challenges and uncertainty into the grid. Demand Response (DR) strategies are applied to address these challenges. DR refers to the practice of actively adjusting electricity consumption in response to signals such as price or incentives from grid operators, utilities, or aggregators. It involves reducing or shifting electricity usage during peak periods or in response to grid constraints to balance supply and demand, enhance grid reliability, and avoid or mitigate grid emergencies. The approach that is used to manage the DR using price as the key operational parameter is called Transactive Controls (TC). TC is a market-based control paradigm that uses “price” as the key operational parameter. GridWise Architecture Council defined it as “a set of economic and control mechanisms that allow the dynamic balance of supply and demand across the entire electrical infrastructure using value as a key operational parameter”. Economists extensively dealt with TC in microeconomics. However, TC is a domain-free approach that integrates market-based coordination and value-based control for a group of resources to achieve global objectives. Furthermore, the Building Energy Management Systems (BEMS) manage TC at the building or zone level in a commercial building. For example, in case of load shedding, it switches off low priority zone air conditioning or raises the set-point for cooling irrespective of usage in the whole building; dims all the lights regardless of the occupants and their needs. The occupant does not get an opportunity at the time of the DR event to decide on which comfort parameters he is willing to forgo to meet the energy demand. Besides, building energy managers usually operate the buildings to maintain homogeneous indoor ambient conditions (like zone temperatures and lighting). However, occupants have individual thermal and visual comfort preferences. Maintaining a homogeneous indoor environment throughout the building/zones leads to unnecessary energy consumption as well as the inability to meet the comfort needs of the occupants. This has led the building science research community to pursue Personal Environment Control Systems (PECS), such as local thermal conditioning systems like heated computer keyboard, personal heaters, desk fans, and radiant cooling cubicles and task lighting systems such as desk lamps. PECS create favourable micro-ambient conditions around each occupant. Nevertheless, the literature study shows that there is a gap and a need for a system/framework to integrate PECS within the task environment and between task & ambient controls to address the challenges. Hence, as part of this thesis, a system, iSPACE - intelligent System for Personal Ambient Control and energy Efficiency, has been developed to address the challenges. iSPACE integrates transactive control methods to facilitate demand response strategies within personal environmental control systems. This thesis introduces an innovative approach to integrating Personal Environmental Control Systems (PECS) into building energy management, emphasising demand response through transactive controls. It addresses the limitations of traditional demand response mechanisms by empowering individual occupants to manage energy usage at a granular level. The proposed framework establishes a hierarchical distributed multi-agent system architecture, seamlessly integrating PECS devices like SmartHub, RadiantCubicle, and SmartStrip into building energy management systems. The focal point of this thesis is the implementation of transactive control within the building environment, facilitating interactions between energy-consuming devices and the building systems at a localized level. While traditional supply-demand balancing occurs at the grid level by utilities or balancing authorities, our research explores the efficacy of implementing transactive control within buildings to optimize energy usage and enables end-users to participate in managing DR events at the task level based on their priorities. Personalised demand response strategies are facilitated by enabling real-time interaction between occupants and energy-consuming devices. Key contributions include developing and implementing transactive controls at the task level, allowing users to adjust energy consumption based on dynamic pricing signals. Detailed features, system conceptualisation, mathematical modelling, and pricing formulation are provided, along with comparisons of transactive control platforms. The framework's efficacy is demonstrated through case studies and simulations. The metrics indicate a 26% energy demand flexibility compared to the benchmark, highlighting the substantial flexibility it offers for demand response management. Also, demonstrated that 100% convergence is possible by simulation study using the ground truth data derived from the experiment, which consisted of 1M test runs each at various levels (Building, Zone, and Task levels) on random system states and various parameter changes. Recommendations address system performance, scalability, and limitations, supported by an online codebase and hardware design. Establishing a functional testbed with the iSPACE prototype at IIITH's FDD lab fosters further research and collaboration. Overall, this thesis offers insights and methodologies to advance energy management practices in smart buildings, contributing to more sustainable and responsive built environments.