Peak load shifting is scheduling flexible electricity use away from high-rate windows. This guide shows how to calculate savings from peak load shifting with shiftable monthly kWh, peak vs. off-peak tariffs, and the dollar spread per shifted kilowatt-hour.
Benefits
- Quantifies peak shaving as kWh removed from the peak rate block.
- Monthly savings = shifted kWh × (peak $/kWh − off-peak $/kWh).
- Pairs with EV, laundry, and pool-pump scheduling for realistic shift targets.
How it works
- Identify kWh per month that currently run during peak hours but could move.
- Enter peak and off-peak $/kWh from your utility TOU schedule.
- Multiply shifted kWh by the rate spread for monthly and annual savings.
FAQ
How do I calculate savings from peak load shifting?
Savings per shifted kWh = peak $/kWh − off-peak $/kWh. Monthly savings = shiftable kWh × that spread. Example: 280 kWh/mo moved off a $0.38 peak block to $0.12 off-peak → $0.26/kWh spread → 280 × 0.26 ≈ $72.80/mo (~$874/yr). Count only kWh you will actually reschedule.
What is peak load shifting vs. peak shaving?
Peak load shifting moves the same energy to a cheaper time slot—total kWh stays similar, but fewer kWh bill at peak rates. Peak shaving can also mean lowering instantaneous demand (kW) for commercial demand charges. This calculator focuses on energy-rate shifting between TOU periods.
How much load can I realistically shift off peak?
Start with discretionary loads: EV charging (often 200–400 kWh/mo), dishwasher and dryer cycles, pool pumps, and water-heater elements. Smart plugs or interval meter data help estimate peak-hour kWh. Fixed baseload—fridges, routers—usually stays put.
Technical specifications
- Rate spread = peak_rate − off_peak_rate.
- Shifted monthly savings = shiftable_kWh × rate_spread.
- Annual savings ≈ monthly_savings × 12.
- Related: time-of-use-electricity-savings-calculator, peak-shaving-potential.