EV Fleet Demand Charge Exposure Calculator

Estimate monthly demand charge exposure for an EV fleet depot and see how peak-shaving or buffering shifts the bill after mitigation costs.

Highest 15- or 30-minute interval demand recorded in the billing cycle.
Tariff demand charge applied to the measured peak.
Target peak after load shifting or buffering. Defaults to the measured peak when blank.
Subscription or leasing cost for batteries, EMS, or scheduling software. Defaults to $0 when blank.

Informational estimate only. Validate tariff details, ratchet rules, and operational constraints before financial commitments.

Examples

  • 480 kW peak with a $18.50/kW tariff, managed down to 360 kW with $1,200 mitigation spend ⇒ Baseline $8,880.00, managed $6,660.00, gross savings $2,220.00, net savings $1,020.00.
  • 325 kW peak at $22.00/kW, no managed peak entered (defaults to 325 kW) and no mitigation cost ⇒ Baseline and managed both $7,150.00, net savings $0.00.

FAQ

What counts as the monthly peak?

Use the highest 15- or 30-minute kW interval from the utility demand meter during the billing month. For utilities with ratchet clauses, use the ratcheted peak instead of the raw interval reading.

Can I include battery degradation costs?

Yes. Add the amortized monthly degradation or lease cost to the mitigation field so the net savings reflects the true cost of peak shaving.

Does this cover energy charges?

No. The calculator isolates demand charges. Energy charges (kWh) should be modeled separately, but lowering peaks often slightly shifts energy charges when you move charging to different hours.

Additional Information

  • Result unit: demand charges expressed in USD per monthly billing cycle.
  • Managed peak defaults to the measured peak when left blank, yielding zero savings unless a lower target is provided.
  • Mitigation cost defaults to $0, so the calculator reports gross savings unless you enter a monthly control cost.

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