Canadian Solar’s e-STORAGE launches 8.36 MWh modular battery

Canadian Solar’s battery storage unit, e-STORAGE, has introduced its next-generation utility-scale battery energy storage system, FlexBank 1.0. The modular solution offers up to 8.36 MWh of storage capacity per unit and a projected lifespan of up to 20 years.

At the core of FlexBank 1.0 is a new modular open-frame architecture which enables each cabinet to function as an independent building block. According to the company, this design streamlines logistics and on-site installation, providing a high degree of layout flexibility.

The system is based on 314 Ah lithium iron phosphate (LFP) cells, currently a dominant standard in the industry. For instance, China Electric Equipment Group’s recent 7,248 MWh centralized procurement awarded nearly all contracts to 314 Ah products. However, e-STORAGE notes that FlexBank’s platform is designed to support upcoming larger form factor cells with higher amperage – with products exceeding 500 Ah already commercially available.

With 8.36 MWh per unit, FlexBank 1.0 ranks among the most energy-dense solutions on the market, second only to CATL’s 9 MWh TENER Stack, launched earlier in 2025.

As energy density increases, so do system weight and logistical challenges. e-STORAGE’s latest product, comprising five cabinets, weighs approximately 68 tonnes and has dimensions of 10.5 meters in length, 2.7 meters in width, and 3.15 meters in height. Despite its scale, the company highlights the advantages of its skid-mounted design, which enables fast on-site assembly and flexible installation options, including side-by-side and back-to-back configurations. Each individual cabinet, including the battery, weighs around 13 tonnes, making transport and deployment more manageable.

“This flexibility reduces EPC costs while maximizing project energy density. The system is fully compatible with power conversion systems, ensuring seamless integration for both new deployments and site augmentations,” the company said.

The five-cabinet FlexBank 1.0 system can be configured for either two- or four-hour storage durations. The two-hour variant delivers a rated DC power of 4 MW, while the four-hour version is rated at 2 MW. The round-trip efficiency is 93% for the two-hour system and 94% for the four-hour version. The system operates within a DC voltage range of 1,164.8 V to 1,497.6 V and is designed to function reliably in ambient temperatures from -30°C to 55°C.

On the safety front, FlexBank 1.0 features a multi-tiered protection system. Within each cabinet, cells are protected by heat barriers, a three-level electrical protection system, and advanced cell-level precision management. The modular design is engineered to prevent thermal propagation between cabinets, substantially mitigating fire risk.

Colin Parkin, President of e-STORAGE, stated, “FlexBank 1.0 is the strategic evolution of our utility-scale energy storage platform, engineered to address our customers’ critical needs for safe, adaptable, and cost-effective solutions. By dramatically simplifying deployment, we are providing a more reliable and adaptable technology that will accelerate the global transition to renewable energy and deliver tangible value for developers and investors.”

FlexBank 1.0 will be showcased at Canadian Solar’s booth V10031 RE+ 2025 in Las Vegas, Nevada, from September 9 to September 11, 2025.