BESS Economic Sensitivity by Capacity

This page compares the main economic KPIs across BESS sizes.

The charts help identify the trade-off between larger batteries, higher annual savings, lower capital efficiency, and payback risk.

1. Internal Rate of Return vs. BESS Capacity

This chart shows how capital efficiency changes as BESS size increases.

The WACC hurdle is shown as a benchmark. Configurations above that line generate an IRR higher than the assumed cost of capital.

Figure 1. IRR vs. BESS capacity. The attractive range is where IRR remains above the WACC hurdle.

2. Annual Cost Saving vs. BESS Capacity

This chart shows the annual economic benefit generated by each BESS size.

It helps distinguish between the configuration that maximizes annual savings and the one that maximizes capital efficiency.

Figure 2. Annual saving vs. capacity. Larger batteries may generate more total savings, but not necessarily better financial returns.

3. Payback Period vs. BESS Capacity

This chart shows how many years are required to recover the initial investment.

Configurations with very long or missing payback values should be treated as weak or non-bankable.

Figure 3. Payback vs. capacity. Missing values indicate configurations that do not pay back within the project lifetime.

4. Net Present Value vs. BESS Capacity

This chart shows value creation after discounting future benefits.

Only configurations with positive NPV create value under the assumed discount rate.

Figure 4. NPV vs. capacity. The optimal economic configuration is the one with the highest positive NPV, not necessarily the largest BESS.

5. IRR vs. Annual Saving Trade-off

This chart highlights the trade-off between financial return and absolute annual benefit.

Moving right usually means higher annual savings. Moving down usually means lower capital efficiency.

Figure 5. Each point is one BESS capacity. Moving right along the curve means larger capacity and higher annual savings, often with lower IRR.

BESS Economic Summary

This table summarizes the main economic indicators for each BESS size considered in the simulation.