BESS Sizing: How to choose the right size

Correct sizing is critical

A BESS that is too small will not deliver the desired effect, while an oversized system ties up unnecessary capital. Correct sizing requires analysis of consumption data, electricity prices, and intended use.

Key parameters

The most important parameters are power (kW) and energy capacity (kWh). Power determines how much electricity the system can deliver at once, while capacity determines how long it can deliver. The ratio between these is called the C-rate.

For peak shaving, a C-rate of 0.5–1C is typically needed. For frequency regulation, 1–2C may be required. Globe Energy helps you analyse consumption data and find the optimal sizing.

Step-by-step method

1. Collect 12 months of consumption data (15-minute intervals). 2. Identify power peaks and consumption patterns. 3. Define goals (peak shaving, self-consumption, backup power). 4. Simulate different BESS sizes against historical data. 5. Calculate ROI for each configuration.