Don't pay peak prices for off-peak tasks—calculate your peak shaving potential and trim your electricity bill significantly by shifting your consumption.
Retail electricity is increasingly a clock problem. Utilities charge more when transformers and feeders are stressed—late afternoon into evening in many North American TOU schedules. Peak shaving is not about using less total energy; it is about paying the off-peak price for work that does not need to happen on-peak.
Why peak shaving works (the “why” behind load shifting)
Grid operators and regulators use TOU price signals to:
- Reduce coincident peak demand without building peaker plants overnight
- Align home EV charging with surplus transmission capacity
- Reward customers who flex without mandatory curtailment events
For you, every kilowatt-hour moved from peak $/kWh to off-peak $/kWh saves the spread:
Savings ≈ shifted kWh × (peak rate − off-peak rate)
Batteries, smart breakers, and delayed appliance starts are delivery mechanisms—the economics are the spread.
Before vs. after your bill
The calculator starts from your real split: how many kWh land on-peak vs. off-peak each month, your tariff tiers, and what share of peak load you can realistically reschedule.
| Input | Why it matters |
|---|---|
| Peak kWh/mo | Volume priced at the expensive tier |
| Off-peak kWh/mo | Baseline cheap energy |
| Rate spread | Cents that fund each shifted kWh |
| Shift % | Honest automation target—not 100% fantasy |
The chart shows monthly bill before and after—the green bar is shorter when shifting wins.
Peak shaving vs. other tariff tools
- TOU Shifting Savings — you already know shiftable kWh
- Peak Shaving Potential — you know peak/off-peak split and test shift %
- Battery Arbitrage ROI — storage automates shifts with round-trip loss
- Demand Charge Calculator — commercial kW ratchets (different beast)
Build a household shift plan
- Pull last 12 months of hourly or TOU-bucket usage from the utility portal
- Tag flexible loads: EV, dryer, dishwasher, pool, water heater timer
- Set automation to finish before morning peak, not merely “start at night”
- Re-run the calculator quarterly as rates change
Peak shaving is disciplined scheduling backed by tariff math. Measure your spread, automate the boring loads, and let off-peak electrons pay for tasks that never needed peak pricing.