What is BESS Sizing?

Battery Energy Storage System (BESS) sizing is the process of determining the appropriate energy capacity (kWh or MWh) and power rating (kW or MW) required for your specific application. Whether for residential backup, commercial peak shaving, or grid-level flexibility, proper sizing ensures system performance, cost-efficiency, and long-term reliability.

Common BESS Applications and Sizing Ranges

• Residential Systems
  Typical size: 5–30kWh
  Used for: solar self-consumption, backup power

• Commercial & Industrial (C&I) Systems
  Typical size: 100–500kWh
  Used for: demand charge reduction, TOU optimization

• Utility & Containerized Systems
  Typical size: 1MWh–5MWh+
  Used for: grid balancing, renewable smoothing, virtual power plants (VPPs)

Key Factors in Sizing a BESS

• Daily Load Consumption (kWh)
  Define average energy needs and backup expectations.
  E.g., 50% backup for 1,500kWh/day load = 750kWh storage needed.

• Peak Load (kW/MW)
  Determines the required power output and inverter capacity.

• Depth of Discharge (DoD)
  Most LFP batteries allow 90–95% DoD.
  Required capacity = usable energy / DoD factor.

• Autonomy (Backup Hours)
  Required storage = Load × Duration / DoD.

• Charging Source & Speed
  PV systems require solar forecasting; grid charging must align with TOU rates.

• Future Expansion
  Modular ESS designs allow flexible scaling as energy demand increases.

Applications That Rely on Accurate ESS Sizing

• Factories with demand charge penalties

• Office buildings with fluctuating peak tariffs

• EV charging stations with rapid load spikes

• Remote homes with off-grid solar setups

• Microgrids combining solar, wind, and diesel gensets

Cost Reference for Common BESS Sizes (EXW Estimate)

The cost of energy storage systems for Common BESS Sizes depends on several factors, including system capacity, storage duration, battery type, control software, installation conditions, and auxiliary equipment.

Pricing is usually quoted under international trade terms such as EXW, FOB, or CIF, depending on project location and logistics preferences. For a tailored quotation based on your specific project needs, it's best to consult directly with the supplier.

How to Select the Right Size for Your Project

• Analyze historical energy usage (preferably 12 months)

• Define your application goals (cost savings, backup, green energy use)

• Work with a professional supplier like Dagong ESS

• Choose certified, scalable, and modular systems

• Ensure compliance with international standards: CE, UN38.3, MSDS, IEC, 3C

Lifespan of a Well-Sized BESS

With high-quality LFP batteries and appropriate sizing:

• Cycle Life: 8,000+ full charge/discharge cycles

• Service Life: Over 15 years

• Oversized systems increase cost, while undersized systems reduce performance and battery lifespan.

Dagong ESS Solutions for All Scenarios

• Residential BESS:

5kWh–80kWh Stackable Systems

5kWh–10kWh Wall-Mounted

5kWh–30kWh Rack Cabinets

• Commercial & Industrial BESS:

100kWh–241kWh Air-Cooled

215kWh–372kWh Liquid-Cooled

• Utility-Scale Containerized BESS:

3.35MWh Liquid-Cooled ESS

5MWh Air-Cooled ESS

All products use LFP batteries, support EMS integration, remote monitoring, and meet international certifications.

Need Expert Sizing Advice?

Contact Dagong ESS
Website： www.dagongess.com
Email： sales@dagongess.com