Sizing an energy storage system (ESS) correctly is critical for both performance and economics. An undersized system won't meet your energy needs; an oversized system wastes capital. This guide walks through the key steps for residential, commercial, and industrial applications.
Step 1: Define Your Application
The sizing approach differs significantly by application:
- Residential Solar+Storage: Focus on self-consumption optimization and backup power
- Telecom Backup: Runtime requirements for base stations during grid outages
- C&I Peak Shaving: Reduce demand charges by shaving peak loads
- Utility-Scale: Grid services, frequency regulation, renewable firming
Step 2: Calculate Required Capacity (kWh)
For Residential Systems
Calculate daily energy consumption from utility bills (average kWh/day). A typical home uses 15-30 kWh/day. For self-consumption, size the battery to store excess solar generation 鈥?typically 5-15 kWh. For backup, determine which critical loads to cover and for how long.
For Commercial Systems
Analyze load profiles to identify peak demand periods. A common approach is to size for 1-2 hours of peak shaving capacity at the facility's peak demand level.
Step 3: Determine Power Requirements (kW)
Power determines how much load the system can handle at once. Consider:
- Maximum instantaneous load the system must support
- Inrush currents from starting motors or compressors
- Inverter capacity and whether you need single or three-phase
Step 4: Consider Depth of Discharge (DoD) and Efficiency
LiFePO4 batteries typically allow 80-100% DoD. For example, a 10kWh battery with 90% DoD provides 9kWh of usable energy. Round-trip efficiency (usually 90-95%) also affects real-world capacity.
Step 5: Plan for Expansion
Choose a system that allows parallel expansion. Many yoyang Technology products support stacking additional battery modules, making it easy to start with a smaller system and scale up as needs grow.
Quick Sizing Reference
- Small Residential: 2.56-5.12 kWh (wall-mounted)
- Large Residential: 10-20 kWh (stackable or all-in-one)
- Small Commercial: 50-200 kWh
- Large C&I: 200-1000+ kWh
Need help sizing a system for your project? Contact our team and we'll help you find the right configuration.