Peak vs Off-Peak Savings Calculator

About the Peak vs Off-Peak Savings Calculator

Shifting electricity use from peak to off-peak hours is one of the simplest ways to reduce your electricity bill on a time-of-use (TOU) plan. The rate difference between peak and off-peak periods can be $0.10–$0.40 per kWh or more. Shifting just 200–400 kWh per month from peak to off-peak can save $30–$100+ monthly.

Common loads that can be easily shifted include EV charging, laundry, dishwashers, pool pumps, and water heaters. Some loads like HVAC can be partially shifted through pre-cooling or pre-heating strategies. Smart home controllers and programmable timers make shifting automatic and effortless.

This calculator quantifies your potential savings based on the amount of electricity you can shift and the rate differential between peak and off-peak periods. Use it to determine whether switching to a TOU plan and shifting your usage patterns will reduce your electricity costs.

Quantifying this parameter enables systematic comparison across facilities, time periods, and equipment configurations, revealing optimization opportunities that reduce both costs and emissions.

When This Page Helps

Knowing the exact dollar value of shifting usage motivates behavior change. This calculator shows monthly and annual savings so you can decide which loads are worth rescheduling to off-peak hours.

How to Use the Inputs

1. Enter the kWh per month you can shift from peak to off-peak.
2. Enter the peak electricity rate.
3. Enter the off-peak electricity rate.
4. View the per-kWh savings, monthly savings, and annual savings.
5. Identify which appliances contribute the most shiftable load.
6. Evaluate whether the savings justify changing your usage habits.

Example Calculation

Tips & Best Practices

• EV charging is the largest shiftable load (200–400 kWh/month).
• Schedule laundry and dishwasher cycles for off-peak hours.
• Pre-cool your home before peak hours to reduce AC during expensive periods.
• Use pool pump timers to run during off-peak hours.
• A smart water heater controller can shift heating to off-peak times.
• Battery storage systems can charge off-peak and supply power during peak.

Maximizing Peak-to-Off-Peak Savings

The key to maximizing savings is identifying your largest shiftable loads. For most households, these are: EV charging (200–400 kWh/month), clothes dryer (40–70 kWh/month), dishwasher (20–40 kWh/month), pool pump (100–300 kWh/month), and water heater (100–200 kWh/month).

Home Battery Arbitrage

A home battery system enables "energy arbitrage" — buying electricity at off-peak rates and using it during peak hours. A 13.5 kWh Tesla Powerwall can shift about 10–12 kWh daily from off-peak to peak, saving $60–$120/month at a $0.27/kWh rate differential.

Behavioral vs Automated Shifting

Manual shifting (remembering to start appliances at certain times) is unreliable. Automated shifting using timers, smart plugs, and built-in delay features ensures consistent savings without lifestyle changes. Invest in automation for the biggest return.

Frequently Asked Questions

• How much can I save by switching to off-peak?

  Typical savings range from $20–$120/month depending on how much load you can shift and the rate differential. EV owners on TOU plans often save $40–$80/month by charging overnight. Families that shift laundry and dishwashers save $10–$30/month.

• What appliances are easiest to shift?

  EV chargers, dishwashers, washing machines/dryers, pool pumps, and water heaters are the easiest to shift since they can be scheduled with timers. HVAC is partially shiftable through pre-cooling/heating strategies.

• Can I shift HVAC to off-peak?

  Partially. You can pre-cool your home 2–3 degrees before peak hours, then let the thermostat coast during peak. This doesn't eliminate peak HVAC use entirely but can reduce it by 30–50%. A smart thermostat automates this strategy.

• Is a home battery needed for TOU savings?

  No, but it helps. A home battery (like Tesla Powerwall) can charge during off-peak hours ($0.08/kWh) and power your home during peak hours ($0.35/kWh), maximizing savings. Without a battery, you can still save significantly by shifting timer-controlled loads.

• What if peak hours conflict with my schedule?

  Most shiftable loads don't require your attention. Use timers and smart plugs to automate dishwashers, laundry, and EV charging. Many appliances have built-in delay-start features specifically for TOU optimization.

• Do all utilities offer TOU plans?

  Most major utilities offer TOU as an option. Some states (like California) are moving toward TOU as the default rate structure. Check your utility's website for available rate plans and compare using your actual usage data.