Model predictive control, solar model, multi-zone
Model Predictive Controllers (MPC) in supervisory level building control systems may employ solar irradiance data to make decisions, particularly for building zones with a high fraction of window area. Solar irradiance on tilted surfaces can be calculated from Global Horizontal Irradiance (GHI) by a common algorithm that includes an empirical correlation to decompose the beam and diffuse components, followed by the application of an anisotropic sky model. Control decisions based on the modeled solar data can be incorrect, particularly if offsite or satellite derived GHI data is employed. This work investigates the impact of uncertain solar estimation on MPC performance with respect to energy consumption and comfort by comparing MPC responses for a multi-zone building based on: measured local Plane of Array (POA) solar data and satellite GHI based modeled POA solar data. The case study results inform the value of information, revealing that MPC decisions based on satellite derived solar data cause comfort violations that depend strongly on the building system characteristics, such as HVAC and internal gains.