Air-Cooled vs Liquid-Cooled Battery Storage: How to Choose a C&I System
Commercial and industrial battery storage is sold per project, not per box. The first two questions are how much power and energy the site needs, and which cooling design fits the load, the duty cycle and the installation room. This guide explains both for installers, EPCs and distributors quoting their first C&I projects.
What a C&I battery does on site
- Peak shaving: the battery covers short load peaks so the site stays below its contracted or billed peak demand.
- PV self-consumption: midday solar surplus is stored and used in the evening instead of being exported at a low feed-in price.
- Time-of-use and dynamic tariffs: the battery charges when grid power is cheap and discharges when it is expensive.
- Backup: with a static transfer switch (STS), critical loads keep running during a grid outage.
Most projects combine two or more of these. The energy management settings decide which use has priority, so agree them with the customer before sizing.
Size power and energy separately
Power (kW) is how fast the battery can charge or discharge; energy (kWh) is how long it can do so. For peak shaving, the power rating comes from the difference between the site’s peaks and the target limit, and the energy from how long those peaks last. For PV self-consumption, the energy comes from the daily solar surplus and the power from the evening load. Ask for at least one year of 15-minute load data, the PV system size and the grid connection capacity before choosing a configuration.
Air cooling vs liquid cooling
| Air-cooled cabinet | Liquid-cooled cabinet | |
|---|---|---|
| SunoraX configurations | 30 kW / 100 kWh, 50 kW / 100 kWh, 50 kW / 160 kWh | 105 kW / 241 kWh, 105 kW / 261 kWh, 125 kW / 261 kWh |
| How it cools | Fans and air conditioning move air through the battery racks | Coolant runs through plates between the cells and a chiller removes the heat |
| Temperature spread between cells | Wider; depends on airflow and room temperature | Narrower; heat is removed close to the cells |
| Typical duty | Daily PV shifting, moderate peak shaving, backup | High daily throughput, frequent cycling, warm plant rooms |
| Footprint | 1150 x 1246 x 2050 mm, up to 1.9 t | 1572 x 1369 x 1990 mm, up to 2.8 t |
| Maintenance | Filters and fans | Coolant level and pump checks in addition |
| Good fit | Shops, offices, cold rooms, workshops, farms, small factories | Factories, logistics sites, hotels, hospitals, larger commercial buildings |
Both cabinets use LiFePO4 cells, connect at 400 V three-phase and accept optional PV and STS integration. Several liquid-cooled cabinets can be combined for larger sites.
When a container makes sense
Above a few hundred kWh, a 20-foot container is usually simpler than a row of cabinets. The SunoraX 20 ft container ESS comes in 250 kW and 500 kW classes with 241 or 261 kWh battery clusters; the number of clusters, the power conversion system and the energy management system are set per project. Typical sites are industrial plants, solar parks and EV charging hubs.
Questions to settle before quoting
- Grid connection: the distribution system operator approves the storage system; in Germany, sites connected at medium voltage follow VDE-AR-N 4110.
- Installation room or outdoor pad: temperature range, ventilation, fire separation and the local fire authority’s requirements.
- Foundation and access: a 2.8 t cabinet or a container needs a crane or forklift route and a load-bearing base.
- Monitoring: Ethernet, RS485 or CAN connection to the site energy management or SCADA system.
- Documents: IEC test reports and UN38.3 for the battery; under the EU Batteries Regulation, industrial batteries above 2 kWh need a digital battery passport from 18 February 2027. See the EU compliance checklist.
- Installation and commissioning by a qualified local installer.
SunoraX C&I models
- Air-cooled C&I cabinet: 30 to 50 kW, 100 to 160 kWh, IP55.
- Liquid-cooled C&I cabinet: 105 to 125 kW, 241 to 261 kWh, IP54 or IP55.
- 20 ft container ESS: 250 kW or 500 kW class, clusters of 241 or 261 kWh.
Configuration, documents, warranty and delivery terms (FOB China or from European stock) are confirmed in the project quotation.
Send your project data
Share the load profile, PV size, grid connection and country. We reply within one business day with a suggested configuration and quotation.
Frequently asked questions
What is the difference between air-cooled and liquid-cooled battery storage?
Air-cooled cabinets move air through the battery racks with fans and air conditioning. Liquid-cooled cabinets run coolant through plates between the cells and remove the heat with a chiller, which keeps a narrower temperature spread between cells and suits high daily throughput and warm plant rooms.
When is an air-cooled commercial battery cabinet enough?
For daily PV shifting, moderate peak shaving and backup at sites such as shops, offices, cold rooms, workshops, farms and small factories. SunoraX air-cooled cabinets come as 30 kW / 100 kWh, 50 kW / 100 kWh and 50 kW / 160 kWh.
When does a 20 ft battery container make sense?
Above a few hundred kWh, where one container is usually simpler than a row of cabinets. The SunoraX 20 ft container ESS comes in 250 kW and 500 kW classes with 241 or 261 kWh battery clusters, configured per project.
What data is needed to size a commercial battery?
At least one year of 15-minute load data, the PV system size and the grid connection capacity. Power (kW) and energy (kWh) are sized separately: from the peaks to be shaved and how long they last, or from the daily solar surplus and the evening load.
Last updated: