Assessing the Effectiveness of the Energy Storage Rule-Based Control in Reducing the Power Flow Uncertainties Caused by Distributed Photovoltaic Systems

Marco Pasetti

doi:10.3390/en14082312

Abstract

Battery energy storage systems (BESSs) are increasingly adopted to mitigate the negative effects caused by the intermittent generation of photovoltaic (PV) systems. The majority of commercial BESSs implement the self-consumption, rule-based approach, which aims at storing the excess of PV production, and then reusing it when the power demand of the loads exceeds the PV power generation. Even though this approach proved to be a valid solution to increase the self-consumption of distributed generators, its ability to reduce the power flow uncertainties caused by PV systems is still debatable. To fill this gap, this study aims at answering this question by proposing a dedicated set of key performance indicators (KPIs). These KPIs are used to evaluate the performance of a 13.8 kWp/25.2 kWh Lithium-Ion BESS coupled with a 64 kWp PV system. The results of the study revealed that the impact of the storage system had almost negligible effects on the uncertainty of the net power flows, while showing better results in terms of the reduction of the absolute power ramps, particularly during the BESS charge stages. These results represent an interesting point of discussion by suggesting that different storage control approaches should be investigated.

Highlights

The progressive paradigm shift towards distributed and decarbonized energy systems is heavily affecting the operation of modern power grids
As can be noted by the results shown in the previous tables, the daily peak of the grid active power demand slightly decreased due to the contribution of the PV power generation, with a relative reduction on the order of a few % points
As can be noted by the results shown in the previous tables, the daily peak of the grid active power demand slightly decreased, with a relative reduction of almost 2%

Summary

Introduction

The progressive paradigm shift towards distributed and decarbonized energy systems is heavily affecting the operation of modern power grids. As will be discussed in detail, despite several research studies in the literature proposing very different strategies and optimization algorithms for the charge and discharge control (or scheduling) of BESSs, the majority of commercial systems on the market implement the classic self-consumption, rule-based approach [7]. This control strategy aims at maximizing the self-consumption rate (SCR) of RES generators, i.e., the amount of energy produced by the RES generator and directly self-consumed by the user’s loads, by storing the excess of RES production and reusing it when the power demand of the loads exceeds the power generation of the RES. Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations

Objectives

Results

Conclusion