Energy Storage

BESS Sizing Guide: MW Power vs. MWh Energy Capacity

Understand how utility-scale battery energy storage systems (BESS) are sized, duration ratios, and efficiency losses.

David Rodriguez, Storage Architect

• 12 августа 2026 г.

Battery Energy Storage Systems (BESS) Explained

Modern grid batteries are described by two distinct metrics: MW (Power rating) and MWh (Energy capacity).

A 100 MW / 400 MWh battery system has a 4-hour discharge duration at maximum output:

Duration (Hours) = Capacity (MWh) ÷ Power (MW) = 400 MWh ÷ 100 MW = 4 hours

These systems are crucial for time-shifting solar energy from midday peaks to evening high-demand periods.