Demand Charge Savings Estimator

Estimate how much you can save by reducing peak kW—before you invest in controls, storage, or upgrades.

Educational only. Tariffs can include ratchets and seasonal rules. Use this as a directional estimate.

Processed in-browser. Nothing is stored.

Inputs

kW

Your typical monthly peak

$

From your utility bill

kW

How much peak reduction you're targeting

Optional Adjustments

Per year (default 12)

%

Haircut if uncertain

Results

Enter inputs and click Calculate

How to use this tool

  1. 1Enter your current peak demand (kW) for a typical month.
  2. 2Enter your demand charge rate ($/kW-month) from your utility bill.
  3. 3Enter a target reduction (kW or %).
  4. 4Review estimated savings.
  5. 5Use the result to prioritize: operational changes first, then controls, then hardware (storage).

What the results mean

Demand charges often bill you for your "worst moment" in the month.

Reducing peaks can save money even if total kWh barely changes.

Example (sanity check)

If demand rate = $20/kW-month and peak reduction target = 50 kW:

Monthly Savings

$1,000

50 kW × $20/kW

Annual Savings (12 months)

$12,000

$1,000 × 12

Common pitfalls

  • Using the wrong demand rate (some bills have multiple demand components)
  • Ignoring ratchets or seasonal pricing (real savings could differ)
  • Assuming you can reduce peak without monitoring interval data
  • Reducing peaks by sacrificing comfort or uptime

Change log

v1.0 (2026-01): Latest release