How to Choose the Right Lithium Battery Capacity

When selecting a lithium battery system for solar and energy storage, bigger isn’t always better. Capacity requirements vary widely—from kilowatt-hours for residential use to megawatt-hours for grid applications. The key to efficient energy storage lies in accurately matching capacity to your actual needs.

Home Energy Storage: 5–20 kWh

For households, the right capacity depends on daily energy consumption, backup requirements, and available installation space.A typical 5 kW solar system pairs well with 5–10 kWh of storage—sufficient to power a home at night using solar energy generated during the day.For extended power outages or extreme weather, 20 kWh can support essential appliances for 2–3 days.It’s also important to consider physical space—most home battery systems are designed to fit within a compact footprint.

Commercial & Industrial Storage: 50–500 kWh

For businesses, energy storage is an economic decision.By leveraging differential electricity pricing (For example, with time-of-use rates (e.g., US$0.20/kWh peak vs. US$0.07/kWh off-peak), a 500 kWh battery system can save approximately US$65 per day (actual savings depend on local rates). This typically results in a payback period of 3 to 5 years.）Capacity should align with operational load: for example, a 100 kW load paired with 500 kWh storage provides 5 hours of continuous operation, covering most peak tariff windows.

Grid-Scale Storage: 1–100 MWh

At the grid level, energy storage is measured in megawatt-hours (MWh).For instance, CATL’s integrated “PV + Storage + Charging” stations can reach 100 MWh—enough to supply 100,000 households for one hour.These large-scale systems help balance grid supply and demand, store surplus solar or wind energy, and improve overall grid stability.Each project is tailored to specific grid conditions and renewable energy integration needs.

How to Determine the Right Capacity for You

Define Your Goal: Is it energy self-consumption, cost reduction, or backup power?

Analyze Energy Usage: Examine your electricity bills and consumption patterns.

Assess Installation Space: Confirm that the system can be accommodated physically.

Evaluate ROI: Compare initial investment against long-term savings or benefits.

Consider Future Expansion: Opt for modular systems that allow for easy capacity upgrades.

In the age of energy transition, choosing the correct battery capacity is essential to maximizing value—whether for home, business, or grid applications.

If you're uncertain about the best capacity for your needs, consult a Greensun engineer for professional guidance.