A novel centralized storage model for distributed photovoltaic generation systems

The growing demand for solar power renders it as one of the most valuable renewable sources for electrical energy production, but its intermittent nature limits its application. To overcome this limitation, electric storage devices, such as battery energy storage systems, are used to fill the void. However, battery energy storage systems are relatively expensive and usually suffer from low utilization especially if provisioned to accommodate the peak load. In this paper, a centralized battery storage model for distributed photovoltaic systems is proposed to improve the storage system utilization and reduce the power grid dependency. The proposed model consists of detailed analytical models of the photovoltaic and energy storage systems. To validate the proposed model, a comparative analysis was conducted to highlight the grid power dependency of the proposed centralized and current decentralized storage models using various synthetically generated load profiles. In addition, a case study where a centralized battery storage model for 60 residential locations was used to validate the proposed model using actual location-based hourly irradiance, temperature, and load demand. It was concluded that the proposed model improved the storage devices utilization by virtually smoothing out the high variation (peak loads) within the load profiles accommodated by the storage system. The power grid dependency of this centralized storage model was evaluated and compared with the conventional decentralized storage model. As a result of using the centralized storage model, the utilization of the grid was reduced by 16.8% compared to the decentralized model for the same PV generation and storage capacity.