Demand Charges vs. TOU Rates for Home EV Charging: What Matters (and How to Avoid Peak Costs)

What’s the difference: demand charges vs TOU?

TOU (time-of-use)

TOU rates change the price per kWh depending on the hour/day/season. You pay more during peak demand windows and less when the grid is underutilized.

Example: SDG&E’s EV-TOU-5 plan highlights an on-peak window of 4–9pm and a super off-peak window midnight–6am (prices effective Jan 1, 2026). Source: sdge.com

Demand charges

Demand charges bill you for your highest power draw (kW) during the billing period—often your maximum 15-minute (or hourly) demand.

Plug In America’s primer explains demand charges as a way to pay for grid capacity built to meet maximum demand—typically applied to larger commercial/industrial customers, not most residential customers. Source: pluginamerica.org

Do homeowners pay demand charges for EV charging?

Usually no—most EV owners charging at home are residential customers billed mainly by kWh.

That said:

• Some utilities are experimenting with new residential bill structures.
• Certain “special” residential tariffs (or home + solar + battery programs) may include demand-style components.

If you’re unsure, look for a line item that mentions:

• “Demand (kW)”
• “Max demand”
• “Peak kW”

If you only see “kWh” and time-period pricing, you’re likely on TOU without demand charges.

Why peak power still matters even without demand charges

Even if you’re not billed a demand charge, your utility’s highest-cost hours are generally the times when the grid is under the most strain.

Research summarized by NBER shows EV charging behavior responds to incentives that shift charging to off-peak hours—helping reduce system costs for EV integration. Source: NBER off-peak charging study

And state energy groups have documented how demand-charge design can make EV charging economics tricky—especially for higher-power charging. (Good context even for homeowners.) Source (NASEO PDF): naseo.org

How to lower EV charging cost under TOU (and reduce peak stress)

1) Move charging to the cheapest window

If your plan has super off-peak, start there.

• Set your EV/charger schedule to begin after off-peak starts.
• Avoid “plug in at 6pm and forget it” if 4–9pm is on-peak.

If you want a simpler way to manage TOU schedules and see cost impacts over time, this is where the NeoCharge App can help: NeoCharge App

2) Don’t stack big loads

A common (avoidable) pattern:

• EV charging (7–11 kW)
• • electric dryer / oven / water heater
• • AC compressor

Even if you don’t have demand charges, this can push usage into expensive TOU blocks or increase total household kWh during peak windows.

3) Use load management when the constraint is electrical capacity

If your challenge is “I need to charge, but I also need my dryer/other appliance,” hardware load management helps prevent simultaneous operation.

If you share an outlet or circuit (e.g., dryer + EV), consider an automatic solution like NeoCharge Smart Splitter: NeoCharge Smart Splitter

4) Consider a lower amperage charging setting

If your utility’s peak window is short (e.g., 4–9pm), and you must charge during part of it, reducing current can lower your peak power draw and finish the rest overnight.

Quick checklist: which plan should I choose?

Choose a TOU EV plan if:

• You can reliably charge overnight
• You want a clear “cheap window” for charging

Be cautious with demand-style tariffs if:

• You have many large electric loads that overlap
• You frequently need to charge at high power during peak times

When in doubt: run a 1–2 month experiment with off-peak-only charging and compare bills.

FAQ

Are demand charges the same as peak kWh pricing?

No. TOU changes your price per kWh by time. Demand charges bill you for the single highest kW draw.

What’s the biggest EV charging cost lever at home?

For most households: when you charge (TOU scheduling) and avoiding expensive on-peak windows.

Can I avoid a panel upgrade and still charge off-peak reliably?

Often yes—especially if your limitation is sharing a circuit/outlet. Load management devices can sequence loads so you can charge during your cheapest window without tripping breakers.

Next steps (NeoCharge)

• Set up TOU-aware scheduling and track savings: NeoCharge App → NeoCharge App
• Need to share a 240V outlet safely (dryer + EV) or avoid a panel upgrade via load management? Smart Splitter → NeoCharge Smart Splitter