ESS_WG_1562 - Working Group for Energy Storage Subsystems

Mark Siira

IEEE-SASB Coordinating Committees

This recommended practice provides a procedure to size a stand-alone photovoltaic system. Systems considered in this document consist of PV as the only power source and a battery for energy storage. These systems also commonly employ controls to protect the battery from being over- or undercharged, and may employ a power conversion subsystem (inverter or converter). The issues of array utilization, battery-charge efficiency, and system losses are also considered in terms of their effect on system sizing. This recommended practice is applicable to all stand-alone PV systems where PV is the only charging source. This document does not include PV hybrid systems nor grid-connected systems. The hybrid systems referred to in the preceding sentence are off-grid but have multiple energy sources such as diesel generator, solar PV, and wind. This document is intended to be used in conjunction with IEEE Std 1013-2019 Recommended Practice for Sizing Lead-Acid Batteries for Stand-Alone Photovoltaic (PV) Systems. This recommended practice does not include the sizing of the system controller, inverter, wiring, or other system components.

Design considerations and procedures for storage, location, mounting, ventilation, assembly, and maintenance of lead-acid storage batteries for terrestrial photovoltaic (PV) power systems are provided. Safety precautions and instrumentation considerations are included. This standard applies to all terrestrial photovoltaic power systems, regardless of size or application, that contain storage subsystems. The installations addressed apply to the operation of an ac, ac/dc, or dc system with the battery, PV generating subsystem, and load all connected in parallel.

This guide is applicable to all stand-alone photovoltaic (PV) systems where PV is the only charging source. Stand-alone photovoltaic (PV) system parameters and operating conditions are discussed in relation to battery characteristics and expected system performance. Charging parameters for PV systems are suggested to help in the selection of a battery for a specific application. Finally, a performance test to verify the battery selection and system parameters is provided, including discussions on how to interpret test results. Test results only provide information on initial battery performance. No cycle-life predictions are made.

This recommended practice presents tests to determine the performance of stand-alone photovoltaic (PV) systems and for verifying PV system design. These tests apply only to complete systems with a defined load. Performance testing is conducted outdoors under prevailing conditions over a period of about one month. These tests are intended to assist designers, manufacturers, system integrators, system users, and laboratories that will conduct the tests. System safety and component reliability issues are not addressed in this recommended practice.

A method for properly sizing the PV array and battery for stand-alone PV systems where PV is the only charging source is recommended (in conjunction with IEEE Std 1013(TM)). Load calculations and determination of solar radiation in the sizing of the system need special attention. Additionally, the critical nature of the load in deciding an acceptable annual availability needs to be considered.

This guide is applicable to lead-acid batteries that are used as the energy storage component in remote hybrid power supplies. The remote hybrid application, with its dual generator option, i.e., both renewable and dispatchable generation, is advantageous in that the battery can usually be charged at will and under circumstances that may also be advantageous for the dispatchable generator. The normative references provide guidance to battery safety, installation, and maintenance considerations. This guide discusses battery selection, sizing, and management issues, e.g., cycling, charging, and the effect of temperature and charge-discharge rates on performances such as life and capacity. An informative annex discusses the several lead-acid technologies.

This guide is specifically prepared for a PV/engine generator hybrid power system, but may also be applicable to all hybrid power systems where there is at least one renewable power source, such as PV, and a dispatchable power source, such as an engine generator. Taper-charge parameters for PV hybrid systems are suggested to help in preparing the battery for a capacity test. A test procedure is provided to ensure appropriate data acquisition, battery characterization, and capacity measurements. Finally, a process to review test results and make appropriate decisions regarding the battery is provided. No cycle-life predictions are made.

Design considerations and procedures for storage, location, mounting, ventilation, assembly, and maintenance of lead-acid secondary batteries for photovoltaic power systems are provided. Safety precautions and instrumentation considerations are also included. Even though general recommended practices are covered, battery manufacturers may provide specific instructions for battery installation and maintenance.

A method for determining the energy-capacity requirements (sizing) of both vented and valve-regulated lead-acid batteries used in terrestrial stand-alone photovoltaic (PV) systems is described. Sizing batteries for hybrid or grid-connected PV systems is beyond the scope of this document. Installation, maintenance, safety, testing procedures, and consideration of battery types other than lead-acid are beyond the scope of this document. Recommended practices for the remainder of the electrical systems associated with PV installations are also beyond the scope of this document.

Design considerations and procedures for storage, location, mounting, ventilation, assembly, and maintenance of lead-acid storage batteries for photovoltaic power systems are provided in this standard. Safety precautions and instrumentation considerations are also included. Even though general recommended practices are covered, battery manufacturers may provide specific instructions for battery installation and maintenance.

A method for determining the energy-capacity requirements (sizing) of both vented and valve-regulated lead-acid batteries used in terrestrial stand-alone photovoltaic (PV) systems is described in this recommended practice. Sizing batteries for hybrid or grid-connected PV systems is beyond the scope of this recommended practice. Installation, maintenance, safety, testing procedures, and consideration of battery types other than lead-acid are beyond the scope of this recommended practice. Recommended practices for the remainder of the electrical systems associated with PV installations are also beyond the scope of this recommended practice.

This guide is applicable to lead-acid batteries that are used as the energy storage component in remote hybrid power supplies. The remote hybrid application, with its dual generator option, i.e., both renewable and dispatchable generation, is advantageous in that the battery can usually be charged at will and under circumstances that may also be advantageous for the dispatchable generator.

This guide is specifically prepared for a PV/engine generator hybrid power system, but may also be applicable to all hybrid power systems where there is at least one renewable power source, such as PV, and a dispatchable power source, such as an engine generator. Taper-charge parameters for PV hybrid systems are suggested to help in preparing the battery for a capacity test. A test procedure is provided to ensure appropriate data acquisition, battery characterization, and capacity measurements. Finally, a process to review test results and make appropriate decisions regarding the battery is provided. No cycle-life predictions are made.