Feasibility Analysis of PV-Battery and PV-TES for Cooling Application in Buildings

Abstract

Battery storage is often used in PV-grid connected system to offset the peak electricity demand but is an economically costly option. Thermal energy storage (TES) could be an economically viable option due to its less installation and O&M costs. Literature shows techno-economic feasibility of the PV-TES and PV-battery and, also reveals that PV-TES leads to less self-consumption of the PV compared to PV-battery due to poor control, which causes misalignment of the PV generation and TES operation. In this study, an advanced control strategy, i.e., Model Predictive Control (MPC) is proposed to operate PV-TES for cooling of the built environment and compare its performance with PV-battery. For the techno-economic comparison of the PV-battery and PV-TES using MPC, a co-simulation framework between EnergyPlus (Building Energy Simulation tool) and MATLAB for MPC deployment is used. An air-conditioned building having a floor area of 463 m2 and residential operation schedule integrated with PV-battery (PV installed capacity 32 kW and battery capacity 86 Ah) and a TES tank (capacity 0.6 GJ) is modelled with EnergyPlus. A MATLAB MPC toolbox is used to formulate and train the MPC model. Feasibility of the considered energy storage systems has been quantified by PV-ratio, Energy storage self-consumption (ESSC) and levelised cost of storage (LCOS). The present study addresses the key question of cost-effectiveness, attractiveness and ready to make essential contributions to flexibility (in demand response of power to cooling) of PV-TES over PV-battery.