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energetica-india-57_asiapowerweek

RENEWABLE ENERGY freeze. Some battery types, like lithiumion and lead-acid, may require integrated temperature management in the battery installation for optimal performance and safety. However, lithium-ion batteries are generally not as sensitive to temperature as lead-acid batteries. Service Provided Various electric system services require different charging and discharging profiles, as well as power requirements. For instance, frequency regulation, which provides and takes away power over a short time period (in seconds) requires many fast charge and discharge cycles. It may also have significant power requirements over short periods. Energy supply shift, also known as load shifting, stores excess renewable energy for later use. This requires longer charge and discharge cycles. Some battery types and designs may be better suited to certain requirements from a performance and life time standpoint than others. This report describes battery storage application areas and considers one or more services batteries provide for renewable energy integration. Battery storage system The battery is only one part of a larger battery storage system, displayed and described below. A battery storage system contains several primary components, including the battery, monitoring and control systems, and a power conversion system. Cell-based batteries consist of individual cells connected into modules and then into packs. Flow batteries consist of external tanks filled with an electrolyte which flows through a reaction stack. Monitoring and control systems, referred to as the battery management system, ensure safety and maximise performance. The battery management system prevents individual cells from overcharging, and controls charge and discharge of the battery. This is important for safety and performance. Battery cells and component monitoring may vary to some degree, in that different types require emphasis on particular issues. For instance, lithium-ion battery packs must emphasise thermal monitoring and controls, given a tendency to overheat. In many of the new devices that are entering on the market, the storage system is also coupled to an inverter to provide one integrated product. In addition, the system may need to incorporate power electronics to communicate with the area utility and adhere to local grid interconnection requirements. For example, while the majority of conventional electric systems run on alternating current (AC), batteries deliver electricity as direct current (DC). This means a power conversion system is required, which contains bi-directional inverters. The power conversion system in this case converts DC power from the battery to AC power for grid use or site demand. With the use of a rectifier, AC flows back to the battery for charging after conversion to DC power. Battery management systems are increasingly complex and expensive for larger battery solutions. For example, one new development is the integration of software technologies and tools to allow for remote tracking, control and management of battery storage systems. With up to date information about wind and sun forecasts, the charging level, expected electricity demand and information about the state of charge of other battery systems, it will become possible to optimise and create intelligent demand and supply assets to manage load. For example, Panasonic has developed the so-called LiEDO platform to remote control distributed li-ion batteries deployed in solar equipped buildings. Furthermore, Panasonic is working on the integration of artificial intelligence into control systems to optimise their services (Katsufumi, 2014).At the same time, significant advances have been made over the last six years. For example, in 2008 22- foot containers with li-ion battery storage systems provided 500 kW, while the same container in 2014 can provide up to 2 MW of capacity �� (Source: IRENA report “Battery Storage for Renewables: Market Status and Technology Outlook”). Figure 2: Battery storage system and primary power component. 52 energetica INDIA · MAY | JUN16


energetica-india-57_asiapowerweek
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