Cooling for Battery Energy Storage System (BESS)
Compact Active Cooling for OEM Battery Energy Storage Systems
Aspen Systems designs and manufactures contact refrigeration systems for integration into Battery Energy Storage Systems (BESS). Our miniature liquid chillers, direct refrigerant cooling technology, and custom cooling designs provide equipment-level cooling where conventional chillers or HVAC systems are too large or difficult to integrate. We have extensive experience in designing and delivering temperature management solutions for battery enclosures, and battery cells to maximize charging, performance, and overall battery life.
Our cooling technology is particularly suited for outdoor battery cabinets, modular BESS, commercial and industrial energy storage, microgrids, remote-site battery systems, and mobile or specialized energy-storage equipment.
Aspen Systems supplies the cooling technology within the larger BESS thermal-management system—we do not manufacture the battery pack or energy-storage system, we specialize in thermal management systems.
Methods for Thermal Management in Your BESS
Cooling architecture depends on heat load, battery temperature, ambient conditions, packaging, and heat-rejection requirements.
Air Cooling
Uses fans to move air through condensers and heat exchangers to reject heat from the enclosure.
- Simple architecture with no coolant plumbing
- Best suited for moderate heat loads
- Dependent on airflow distribution and ambient conditions
- Fans can cause louder audible noise
Liquid Cooling
Circulates coolant through heat exchangers or cold plates for thermal contact with the battery modules.
- Higher heat-transfer capability than air
- Well suited for higher-density battery systems
- Requires pumps and coolant lines
- Coolants are typically EGW, PGW, or water
Direct Refrigerant Cooling (Plate Cooling)
Circulates refrigerant directly through cold plates for direct contact the battery or heat source.
- Eliminates the secondary coolant loop
- Utilizes the cold plate as an active heat sink
- increases reliability by eliminating pumps and fluid circuit
- Well suited for compact, tightly integrated systems
Liquid Cooling for Rapid Charging and High-Power Charging Cables
Battery energy storage systems may be integrated with high-power charging equipment where thermal management extends beyond the battery modules. Rapid charging can create concentrated heat loads in power electronics, connectors, and high-current charging cables that may require dedicated cooling.
Aspen Systems develops compact vapor-compression cooling systems that can be integrated into OEM charging equipment to provide controlled liquid cooling where ambient heat rejection alone is not sufficient. Applications can include liquid-cooled charging cables, charging connectors, power electronics, and other high-heat-load components where equipment size and cooling capacity must be carefully balanced.
For high-power charging applications, cooling requirements should be evaluated around the actual electrical load, coolant temperature, flow requirements, ambient conditions, and available installation space.
When Compact, Active Cooling Makes Sense for BESS
A liquid-cooled BESS does not necessarily require a chiller. If the required coolant temperature can be maintained through ambient heat rejection, a radiator or liquid-to-air heat exchanger may be sufficient.
Active refrigerant-based cooling becomes relevant when the required operating temperature cannot be maintained reliably because of high ambient conditions, high or transient heat loads, limited heat-rejection area, or restricted airflow.
Aspen Systems’ compact refrigeration technology is particularly suited to equipment-level and distributed cooling, including:
- Outdoor battery cabinets
- Modular and distributed BESS
- Microgrid and remote-site battery systems
- Mobile or transportable energy storage
- Specialized OEM equipment incorporating battery storage
Depending on the thermal architecture, Aspen can provide a compact Liquid Chiller Module, Direct Refrigerant Cooling system, or application-specific refrigeration configuration for integration at the cabinet, rack, enclosure, or subsystem level.
Design Around the Actual BESS Operating Point
BESS thermal management is rarely solved by selecting a chiller from a catalog based on cooling capacity alone. Ambient temperature, battery heat load, coolant temperature, available space, power consumption, airflow, and control range all influence how the cooling system performs once integrated into the equipment.
Aspen Systems specializes in compact vapor-compression cooling technology for OEM integration. Our miniature refrigeration systems provide high-capacity cooling in a small footprint, making them particularly well suited for battery cabinets and other applications where thermal performance competes with batteries, power electronics, controls, and safety equipment for limited enclosure space and power consumption.
Depending on the BESS architecture, Aspen can support compact liquid cooling, air cooling, or direct refrigerant cooling, allowing the thermal system to be engineered around the battery and enclosure rather than forcing the OEM design around a conventional cooling package.
Working with Aspen early in the design process allows our thermal engineers to evaluate heat load, ambient conditions, coolant or refrigerant temperatures, available space, power requirements, and heat-rejection conditions before recommending a cooling approach.
Information Aspen Needs to Size Your BESS Cooling System
Providing some basic technical information about your application allows Aspen engineers to evaluate cooling performance and architecture to determine whether an LCM, DRC, or customized system is appropriate.
Please provide, where available:
- Continuous and peak heat load (W)
- Required coolant supply temperature or refrigerant evaporating condition
- Minimum and maximum ambient temperature
- Available input voltage and power
- Environmental and ingress-protection requirements
Frequently asked questions
How do you size a chiller for a BESS?
Start with the continuous and peak heat load, required coolant temperature, maximum condenser ambient temperature, coolant flow requirements, and duty cycle. Chiller capacity should then be evaluated at that operating point rather than from maximum rated capacity alone.
When does a liquid-cooled BESS require active refrigeration?
Active refrigeration may be required when a radiator or liquid-to-air heat exchanger cannot maintain the required coolant temperature under the expected ambient and heat-load conditions. This commonly occurs when coolant temperature approaches or falls below ambient, outdoor temperatures are high, or heat-rejection area and airflow are limited.
What is the difference between liquid cooling and direct refrigerant cooling for BESS?
Liquid cooling circulates a secondary coolant—typically through battery cold plates—and transfers that heat to a radiator or chiller. Direct refrigerant cooling routes refrigerant directly through an evaporator or cold plate in thermal contact with the battery, eliminating the secondary coolant loop.
Can a BESS chiller operate in high outdoor ambient temperatures?
Yes, provided the refrigeration system is designed and sized for the required ambient condition. Cooling capacity changes with condenser temperature, so high-ambient performance should be evaluated at the application’s required coolant temperature and heat load.
Can Aspen develop a custom cooling system for an OEM BESS?
Yes. In addition to standard compact Liquid Chiller Modules, Aspen develops application-specific vapor-compression systems for OEM applications where packaging, capacity, electrical requirements, interfaces, or operating conditions require a different configuration.
Get a Quote | Application Questions
Please send us your requests; our team is happy to help.
You can also reach us by email at: info@aspensystems.com
or by phone number at (508) 281-5322