Model predictive control in phase-change-material-wallboard-enhanced building energy management considering electricity price dynamics

Abstract

Incorporating phase-change material (PCM) wallboards into building envelopes can help reduce electricity costs associated with heating and enhance demand flexibility in dynamic building energy management in response to electricity price volatility. The conventional control strategies adopted in current building energy management systems are ‘reactive’ in nature, hence, they are not ready to exploit the full potential of PCM wallboards for price-based, demand-responsive building control applications. This study proposes a model predictive control (MPC) framework for price-based, demand-responsive control of PCM-wallboard-enhanced space heating systems to minimize electricity costs and maximize demand flexibility by fully exploiting PCM wallboards. A high-fidelity, linear PCM wallboard and building thermodynamics model are developed for computationally efficient building control. The model is then incorporated into an MPC framework considering the PCM wallboard dynamics and dynamic electricity prices. A simulation case study is conducted for a single-family house employing the proposed MPC approach to control its space heating system. Compared to conventional control, the MPC approach reduces space heating electricity costs by more than 60 %. The MPC approach also shifts more than 80 % of peak heating loads to off-peak periods, much higher than conventional control achieves (less than40 %). The simulation results also show good synergistic benefits of MPC in fully exploiting PCM wallboards in optimizing building space heating operation: achieving additional 31.1 % electricity cost savings and 38.7 % peak load shifting than without leveraging PCM wallboards. In contrast, conventional control cannot achieve such synergistic benefits. The proposed MPC framework is also proven computationally viable for real-time building control.