EV Time-of-Use Charging Cost Calculator

Time-of-Use (TOU) Charging Cost

TOU rates charge different prices for electricity at different hours. EV owners can save 30-60% by shifting all charging to off-peak windows — usually overnight.

Typical TOU rate structures (US averages, 2026):

EV-specific TOU plans (PG&E EV-A, Southern California Edison TOU-D-PRIME, etc.):

• Often drop super off-peak to $0.06-0.10/kWh
• Some require minimum 50 kWh/month EV consumption to qualify
• A few include free charging windows (PG&E EV2-A weekend daytime)

The cost calculation: Cost = Charging energy (kWh) × Rate ($/kWh)

For a typical EV (15,000 miles/year, 3.5 mi/kWh efficiency):

• Annual energy: ~4,300 kWh
• Monthly: ~360 kWh
• Cost at peak ($0.40): $144/month
• Cost at off-peak ($0.10): $36/month
• Savings: $108/month, $1,300/year

Charging losses (don’t forget):

• Level 2 home charger: 10-15% loss (battery to wheels)
• 360 kWh delivered ≈ 410 kWh from grid (15% loss)
• Always calculate from “from grid” energy, not battery capacity

TOU plan switching considerations:

• Most utilities allow free switching once or twice a year
• Verify your other usage (HVAC, water heater) isn’t penalized by peak rates
• Some utilities offer EV-only TOU as a separate sub-meter (cheap)
• Call utility — most won’t tell you about EV plans unless asked

Quick comparison: flat rate vs TOU:

• If you can shift ≥80% of EV charging off-peak: TOU saves $$$
• If your home uses lots of A/C in peak hours (4-9 PM): TOU may cost more overall
• Run a few months on each and compare

Smart-charging features:

• All major EVs have schedule/depart-by features (Tesla, Bolt, Mach-E, etc.)
• Home charger TOU integration (Wallbox, ChargePoint Home Flex, Emporia)
• Some utilities offer rebates for installing smart chargers