ALMACENA Project Electrochemical Electricity Storage for System Operation

摘要

The electricity system is facing important challenges associated with the integration of intermittent generation, mainly wind and solar energy generation. This fact, together with the need to manage important variations between peak and off-peak demand and the need to operate the system guaranteeing the security and quality of supply is motivating TSOs (Transmission System Operators) to investigate the contribution of new technologies, such as electrochemical electricity storage. The increasing level of wind and solar energy sources and their inherently un-predictable nature add more urgency to considering Energy Storage Systems as a grid facility to maximize the integration of RES (Renewable Energy Sources). In this context, REE (Red Electrica de Espana) is deploying its ALMACENA project in the framework of R&D activities, whose objective is to analyze the technical capabilities of a 1 MW/3 MWh Grid Storage Solution, provided by A123 Energy Solutions and installed in a transmission substation in Spain (Carmona 400/220 kV) from an operation system point of view. The main applications that will be tested in the following months will demonstrate the contribution to system operation flexibility, efficiency and renewable integration of this Battery Energy Storage System (BESS). The BESS is composed of a 1 MW/3 MWh Grid Battery System (GBS), a 1 MW Power Conversion System (PCS), a cooling system and the communications and control systems. The control system will be able to perform three control modes simultaneously: 1. Load shifting; 2. Power-frequency regulation; 3. Voltage control. An important outcome of the project is to calculate the real, measured efficiency of the system with and without auxiliary consumption; as well as the useful life of the system. It is expected to maintain above 80% of nominal power initial levels during at least 5 years, and the system's expected lifetime should exceed 20 years Control modes are specified remotely from REE control room in Madrid, but are also locally accessible through an HMI in the local substation. Due to average temperatures in Carmona substation (that can reach 40°C in summer), the cooling system plays a key role in maintaining availability and reliability levels of the BESS. The BESS is connected to the tertiary of one of the transformers of Carmona substation in 27 kV through a 27 kV/400 V power transformer. The Battery Storage System is formed of one 16 meter container using 32 battery racks with A123's patented Nanophosphate prismatic lithium-ion cells. As a novelty, the System will be normally operating simultaneously with the 3 control modes activated constantly, taking into consideration the real time operation necessities: especially security of supply, system stability, need for flexibility, efficiency and RES integration. During this standard mode, the BESS will be charging during night hours, in which demand levels are low, but with a higher share of renewable generation. The BESS will then be prepared to discharge during peak hours as required.