In the figure above a schematic of the PEBBLE concept is presented. The building is perceived as a dynamical system comprising the various subsystems and building occupants. This last part is especially important as occupant actions (e.g. opening and closing windows) and activities (e.g. sedentary work) directly influence the thermal behavior of the building and the type of decisions that must be taken. The building responds with respect to external (weather) and internal (user) excitations, according to dynamics prescribed by the building construction, with controllable elements that operate according to the decisions taken by the PEBBLE system.
There are three essential elements to the PEBBLE system. The first is accurate and efficient simulation models for EPBs that incorporate all passive, active and energy-generation elements and, given local weather data and weather prediction models, can be used to predict thermal response, energy requirements, and estimate user comfort. These predictive building models incorporate physical modeling and depart from more traditional and less reliable data-driven approaches. The second is sensors, actuators and interfaces that are used to facilitate communication and information exchange from the physical to the simulation layers. The third element is efficient and robust Building Optimization and Control (BO&C) tools, that use sensor inputs and the thermal models to evaluate potential scenarios, and take (almost) in real-time decisions for the operation of the building subsystems with the goal of maximization of the NEP and retaining building conditions at user-acceptable comfort levels. Building occupants have a dual sensor-actuator role in the PEBBLE framework: through user-interfaces humans act as sensors communicating their thermal comfort preferences to the PEBBLE system, and in return the PEBBLE system returns information with the goal of educating and enhancing energy-awareness of the users, engaging them in the effort of taking proper decisions.
Addressing the three above-mentioned objectives/challenges (EPB modeling, real-time optimization of EPB operations and sensor/actuators/user interfaces) is a prerequisite towards the development of generic methodologies and tools that can be employed for the deployment and operation of EPBs (and also for improving performance of existing buildings). Project PEBBLE is about flexibility and extensibility as it does not require a specific set of modeling tools nor does it rely on a certain building technologies. The common unifying aspect is energy balances and thermal models and so as (models for) new technologies become available can be seamlessly integrated into the proposed framework that will yield tangible methodologies both for existing but also for EPB houses of the future.
PEBBLE's main objective is to develop, implement in real-life buildings and evaluate a fully-functional EPB real-time optimization and control system by
a) Advance methodology and designs and technology in order to appropriately and efficiently address and integrate the aforementioned three components,
b) Integrate the proposed designs in the aim of providing efficient, robust and rapidly-adapting real-time Building Optimization & Control (BO&C) for EPBs of arbitrary scale and complexity, location and design methodologies while
c) Employing sensor, user-interfaces and control devices technologies that are easy-to-deploy and, most importantly, are cost-efficient.