Averages Hide What Decides BESS Returns: Sensitivity and Time-of-Day Pricing

Two features in Ingro Sims that look different are really the same argument. One is sensitivity analysis; the other is Time-of-Day (ToD) tariff pricing. Both exist because averages hide the two things that decide whether a battery pays: which hours are expensive, and how wrong your assumptions can be before the number breaks.

A single IRR is a guess with confidence attached

A business case built on one IRR tells you how a project performs if every assumption turns out exactly right. It says nothing about what happens when they do not.

Sensitivity analysis changes the question. Run 600 cases across ten assumptions and you get the range the project survives, not just its best day. Instead of a single figure, you see how far each input can move before the returns stop working, and which assumptions the outcome depends on most.

Time-of-Day tariffs: the same logic, one level lower

ToD pricing applies the same thinking to the bill itself. Rather than valuing energy at a flat ₹/kWh average, Sims takes your real consumption and reprices it hour by hour against the live ToD order for your state and DISCOM.

That matters because the value of storage sits in the difference between hours. A flat average blends cheap and expensive periods into one number, which hides exactly the gap a battery is meant to capture.

Why both matter for a storage decision

• Which hours are expensive: hourly ToD repricing shows where a battery can actually earn, based on your consumption and your DISCOM's order.
• How wrong you can be: sensitivity runs show the band of outcomes the project survives, so the decision does not rest on one optimistic case.

Together they replace two comfortable averages with the detail a storage investment actually depends on. Both are available in Ingro Sims at sims.ingroenergy.com.