IEEE Std 1013-2019 pdf download – IEEE Recommended Practice for Sizing Lead-Acid Batteries for Stand-Alone Photovoltaic (PV) Systems.
1. Overview This recommended practice provides a systematic approach for determining the appropriate energy capacity of a lead-acid battery to satisfy the energy requirements of the electrical loads of a stand- alone photovoltaic (PV) system. Since this capacity determination (sizing) assumes that no power is available from the array, the resulting battery capacity should be more than adequate to meet the PV system’s load requirements during its normal operation. 1.1 Scope This recommended practice describes a method for sizing both vented and valve-regulated lead-acid batteries in stand-alone PV systems. Installation, maintenance, safety, testing procedures, and consideration of battery types other than lead-acid are beyond the scope of this recommended practice. Sizing batteries for hybrid and grid-connected PV systems is beyond the scope of this recommended practice. Recommended practices for the remainder of the electrical systems associated with stand-alone PV installations are also beyond the scope of this recommended practice. Sizing examples are given for various representative system applications. Iterative techniques to optimize battery costs, which include consideration of the interrelationship between battery size, PV array size, and weather, are beyond the scope of this recommended practice. 1.2 Purpose This recommended practice is meant to assist system designers in sizing lead-acid batteries for residential, commercial, and industrial stand-alone PV systems.
― Battery capacity and functional-hour rate determination (Clause 5). The battery capacity and its discharge functional-hour rate are determined by the specific application’s load(s), autonomy, and battery characteristics (see Annex A). ― Determining number of series-connected cells (Clause 7). The system’s voltage limits (voltage window) determines the required number of cells in series. Several criteria should be examined to assure a workable system. ― Cell capacity and battery size determination (Clause 8). Once the overall battery capacity and number of cells in series have been determined, the final selection of a specific cell can be made and the final battery size can be calculated. NOTE—Because of the interaction of these factors, an iterative process may be needed to determine the optimum battery for the application. ― Battery sizing worksheets (Clause 9). Worksheets that provide a systematic approach to the sizing of a battery for a stand-alone PV system are presented. The application of the worksheets is explained in accompanying text. ― Battery characteristics (Annex A). System performance, life, maintenance, and cost are influenced by the type of battery selected for the PV application. Information regarding lead- acid battery characteristics is presented. ― Examples (Annex B). Examples demonstrating various aspects of battery sizing are presented.