Fluence Launches Highly-Modular 7.5 MWh AC-Based BESS Platform
Fluence Energy, a U.S.-based company, has introduced its latest grid-scale battery energy storage system (BESS) called Smartstack. This innovative system is designed to enhance logistics and maintenance while providing high energy density. Featuring 314 Ah cells, Smartstack can store up to 7.5 MWh of energy.
The Smartstack’s patent-pending architecture departs from the conventional 20-foot container design, instead opting for a modular approach that results in units that are easier to transport. The demand for greater efficiency and reduced costs has led to the adoption of high-capacity cells (300 Ah and above) in grid-scale BESS solutions. However, this trend has introduced logistical challenges, especially in Europe, where many countries impose a 40-ton weight limit for vehicles. For comparison, the most energy-dense utility-scale BESS product currently available is Envision’s 8 MWh system, which employs 700 Ah lithium iron phosphate battery cells and weighs approximately 55 tons.
Fluence’s Smartstack consists of two main components: the Smart Skid and the pods. The Smart Skid serves as a centralized electrical and control command center, incorporating advanced cooling systems, power control hardware, all necessary cabling, and comprehensive monitoring capabilities. The pods are situated on top of the Smart Skid and house the battery cells equipped with integrated sensors. These pods are compatible with cells from various suppliers and can be easily swapped out during maintenance or upgrades, thereby enhancing system uptime.
The Smart Skid measures 7315 mm x 2200 mm x 1524 mm and weighs 11 tons, while each pod measures 1762 mm x 2528 mm x 2550 mm and weighs 15.5 tons. Julian Nebreda, President & CEO of Fluence, stated, “Backed by our industry-leading expertise in developing and deploying innovative solutions globally, Smartstack reimagines how systems are designed, built, and maintained. By addressing critical challenges like supply chain shipping constraints, product density, serviceability, and modularity, we are delivering a platform that is more scalable and easier to operate than competing solutions. This translates to superior project economics for our customers.”
The modular design of Smartstack also supports a more agile and cost-effective supply chain localization strategy. It enables components to be sourced or manufactured locally, optimizing availability, costs, and compliance, while improving resilience against geopolitical and logistical disruptions. Although the market currently offers a wider range of DC blocks, Smartstack is an AC block system, featuring an integrated container with both battery and power conversion system (PCS). This product type was first introduced by Tesla in the 2022 redesign of its Megapack. Recent entrants to the AC block market include Sungrow, Rimac, and Wärtsilä.
Fluence claims that its new system design achieves approximately 30% greater density compared to existing AC-based systems, as well as faster and easier installation. The discharge duration of Smartstack can be adjusted to two, four, six, or eight hours. This liquid-cooled system operates at a DC voltage of 1500 V and offers an impressive availability rate of up to 99%. Additionally, the platform incorporates the same safety features found in Fluence’s Gridstack products, including certification for large-scale fire testing. The battery enclosure has an IP 55 rating and is capable of operating in temperatures ranging from -20ºC to +55ºC, with an optional cold weather kit extending the range to -30ºC.
Smartstack is now commercially available for grid-scale applications worldwide, with customer deliveries set to begin in the last quarter of 2025.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/fluence-unveils-innovative-7-5-mwh-modular-ac-based-battery-energy-storage-system/
