Hybrid multi-duration battery energy storage systems combine storage technologies with different power and energy characteristics to provide flexibility across multiple operating timescales. High-rate battery systems can respond rapidly to sudden load changes, frequency deviations and short-duration balancing needs, while long-duration systems provide sustained energy support for renewable energy shifting, backup power and system balancing.

Coordinated through power conversion systems and control software, typically supported by an energy management system, hybrid BESS can allocate different operating roles to different battery components within one architecture. This allows fast-response storage to manage short, sharp power fluctuations, while longer-duration storage supports energy availability over several hours. The approach is particularly relevant for renewable-heavy grids, critical facilities, large flexible loads and grid-constrained areas where operators require both rapid response and sustained flexibility without relying solely on single-duration storage or fossil-fuel-based standby generation.

Main Outcomes of the Solution

• Sustainability: Supports higher renewable-energy utilization by storing surplus generation, shifting clean electricity across time periods and reducing reliance on fossil-based backup.
• Affordability: Improves storage asset utilization by enabling a coordinated portfolio to provide multiple services, including backup, load balancing, renewable shifting and grid support.
• Reliability & Flexibility: Strengthens system stability by combining fast-response power capability with multi-hour energy support for balancing, backup and frequency-related services.

Key Deployment and Scaling Factors

1. Deploy hybrid storage architecture combining fast-response chemistries (such as sodium-ion) for sub-second to second-scale response with energy-dense chemistries (such as lithium iron phosphate) for sustained multi-hour energy support
2. Implement power conversion systems and control platforms capable of coordinating dispatch across different storage durations, operating modes and response-speed requirements
3. Integrate with renewable generation, onsite loads and grid services to support frequency response, energy buffering, backup power and renewable utilization
4. Manage battery lifetime, degradation and cycling for dynamic operating profiles and multi-service use cases
5. Establish scalable delivery models covering system design, commissioning, operations, maintenance and local service capability
6. Enable market frameworks that support stacking of multiple services across hybrid storage assets

Case study

Xiamen Hithium Energy Storage Technology Co., Ltd. (2025), United States

Hithium has developed a hybrid lithium–sodium battery energy storage architecture intended for applications requiring both rapid response and longer-duration energy support. The concept combines long-duration lithium-based systems with higher-rate sodium-ion battery systems within a coordinated design, offering configurations across multiple durations (specifically 1-hour, 2-hour, 4-hour and 8-hour configurations within Hithium’s ∞Power product family).

In data center reference designs, the high-rate sodium-ion system is designed to manage rapid load fluctuations with millisecond-level response, while the lithium-based system provides backup and sustained energy over longer durations. This enables the system to deliver both fast-response services and multi-hour energy support within a single coordinated architecture. According to company-reported data, for a 4-hour backup configuration the system can achieve lifecycle costs more than 20% lower than diesel-based alternatives, while enabling zero-carbon and low-noise backup power.

A 434 MWh Hithium BESS in Ohio is co-located with a data center, providing on-site load smoothing and peak clipping. Configured as a 217 MW system and operating at approximately one cycle per day, it manages approximately 158 GWh of annual energy throughput. Estimated annual savings of approximately $12 million for the data center operator through reduced peak demand charges and load smoothing (as compliance and power quality management).

References:

1. Hithium Launches the World’s First Lithium–Sodium Full-Duration AIDC Energy Storage Solution at its Third Eco-Day-Hithium
2. Hithium Energy Storage Technology case study submission