Abstract

This thesis presents a methodology for the development of a grey-box control-oriented model for air-based open-loop Building Integrated Photovoltaic/Thermal (BIPV/T) systems with the scope to apply Model Predictive Control (MPC) to the air flow within the BIPV/T channel to achieve optimal BIPV/T – HVAC integration. The Varennes library, the first institutional net-zero energy building (NZEB) in Canada and one of a handful of buildings worldwide hosting a full-scale fully operational BIPV/T system, is used as an archetype for this work. The methodology presented can optimize the design of air-based BIPV/T systems or be applied to commissioned systems facilitating the broader realization of net-zero energy buildings.
BIPV/T systems combine the concept of BIPV and thermal collectors producing simultaneously electricity and heat by passing a fluid underneath their surface. The waste heat can be used for various thermal applications, however a key factor for broader BIPV/T realization is optimal control of these systems to maximize the amount of useful heat. As the available heat recovered from the BIPV/T is closely related to the respective weather conditions and the applied flow rate, optimally controlling the fan speed within the BIPV/T channel can significantly improve their performance.
Both a transient and steady-state model are developed and compared. The developed BIPV/T models are calibrated and validated using experimental and real weather data. The development of the MPC strategy for the commissioned BIPV/T system covering 1/6 of the south-facing roof at the Varennes library is presented. In one studied design variation of the existing archetype, the BIPV/T system is considered to simultaneously send heat to an Energy Recovery Ventilator (ERV) and an air-to-water heat pump (HP) while the opportunity to provide excess heat to adjacent buildings is explored, facilitating in the development of net-zero energy neighborhoods. Finally, the benefits of covering additional area of the Library’s south-facing roof with BIPV/T are examined to facilitate production of useful heat for other buildings in the community.
Through this work the essential parameters an engineer should have measurements for when applying MPC to a commissioned BIPV/T system are identified. This can prove extremely useful during the design stages as to where sensors should be placed and the relative importance of each measurement.
Through MPC, the fan speed is effectively adjusted simultaneously providing heat to the HP and ERV while adequately cooling the PV panels. The COP of the solar heated air-to-water heat pump showed a maximum increase of 32% for a mild sunny day. The BIPV/T that would cover the whole roof was able to produce up to 1.17 kWh/m2 (of roof area) of heat for a mild sunny day and provide 85.5% of this amount to adjacent buildings. Specifically, for a day-care center located near the library the consumed energy related to ventilation could be decreased by up to 36.8% with the heat provided from Library BIPV/T system.