Operation & maintenance costs consist of fixed and variable costs. Fixed costs include cooling and genera l maintenance at the site. Variable costs include recharging the batteries and periodically replacing the batteries. These O&M costs are presented as annual expenses in the prior table. The cooling charge is based on a power managemen t system […]

The cost of an energy storage system is affected primarily by four drivers: (a) the initial cost of the storage subsystem, (b) the cost of the power converter, (c) the cost of the balance of system, and (d) the need to design, engineer, procure, and construct one-of-a-kind systems. The capacity of the plant as well […]

The assumed economic life of the battery system is 30 years, requiring battery component replacements at appropriate intervals. The structure and power conditioning system are expected to last 30 years [18]. Battery replacement charges vary by the type of the battery and the number of years until replacement. One manufacturer claims that the type o […]

The most productive hours of sunlight for PV systems are from 9 AM to 3 PM. Before and after these times, electricity is generated, but at much lower levels [8]. In addition, an afternoon thunderstorm will severely reduce local PV output before it will indirectly reduce the load by cooling ambient temperatures and suppressing solar […]

Table 1 summarizes the performance and cost indicators for the storage portion of the system being characterized i n this report. 4.0 Evolution Overview The 1997 30 kW baseline system is based on a commercially-available 31 kW PV/flooded lead-acid battery system. The battery subsystem is assumed to improve and transition in technology type, changing from […]

The life of a b attery and its energy delivery capability are highly dependent on the manner in which it is operated. Many deep discharges (above 70-80%) reduce the life of lead-acid batteries. High rates of discharge reduce the energy delivery potential of lead-acid batteries. Batteries also have shelf-life limitations. Poor charging practices are responsible […]

This appendix assumes that current R&D activities will lead to significant improvements in the cost and performanc e of battery storage systems. As these improvements take place, battery storage systems will compete with conventional sources of peak electric power generation, such as gas turbines, diesel generators, or uninterruptible power supply units. Flooded lead-acid and VRLA […]

Application: This document describes the use of a battery storage system in conjunction with a PV system to avoi d or reduce the purchase of more costly on-peak power. However, energy storage systems can also play a flexible, multi­function role in an electric supply network to manage resources effectively. Battery energy storage systems are use […]