About the Peak Shaving
Peak shaving uses a battery to discharge during a facility's demand peaks so the grid sees a lower maximum demand. For commercial and industrial consumers billed on maximum demand (kVA/kW), shaving that peak directly cuts the demand-charge component of the bill, which is often a large fixed cost.
Formula
Annual saving = Demand reduced × Demand charge × 12
- Demand reduced
- Peak kVA/kW the BESS shaves off the billed maximum demand
- Demand charge
- Your tariff's demand rate (₹/kVA/month or ₹/kW/month)
How to calculate it
- 1Profile the facility's load to find the height and duration of the demand peaks.
- 2Size the BESS power (kW) to cover the peak height and energy (kWh) to cover its duration.
- 3Discharge during peaks to cap billed maximum demand; recharge during low-demand periods.
- 4Value the kVA/kW reduction at your demand charge across all 12 months.
Worked example
A factory shaving 100 kVA of peak demand on a ₹400/kVA/month tariff saves 100 × 400 × 12 = ₹4.8 lakh a year in demand charges — before adding any energy-arbitrage benefit from the same battery.
What you can calculate
- Peak cut kW
- ₹ savings/month
- DISCOM tariff
- Demand charge
Standards & references
Frequently asked questions
How does peak shaving reduce my electricity bill?
C&I bills have a demand charge based on your highest kVA/kW in the month, independent of energy used. A battery that discharges during your peaks lowers that recorded maximum, so you pay a smaller fixed demand charge every month.
How big a battery do I need for peak shaving?
The power rating (kW) must cover the height of the peak you want to shave, and the energy (kWh) must cover its duration. A short, sharp peak needs high power for a short time; a broad plateau needs more energy. Load profiling determines the right kW/kWh split.
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