EV Charging: Flat Rate vs. Time-of-Use Plan
This shows both rate plans' full total cost side by side, a fuller picture than the simple payback tool for the same underlying decision.
At your inputs, the time-of-use plan costs $2,150 less over 10 years.
| Stay on a flat rate plan total cost over the horizon | $6,200 |
|---|---|
| Switch to a time-of-use plan, charging off-peak total cost over the horizon | $4,050 |
Breakeven: The higher upfront cost is offset by year 0.2, after which the time-of-use plan stays cheaper.
- This uses planning estimates you entered, not a contractor quote or guaranteed savings.
- This compares two rate plans on EV charging cost only, not your whole household electricity bill.
What this also tells you: Even if your annual costs are 20% higher or lower than entered, the same option stays cheaper, with the advantage ranging from $1,710 to $2,590.
This is a planning estimate based on your entries. It does not size equipment, determine electrical or building-code compliance, verify incentive eligibility, or replace a contractor quote or professional energy audit.
Why this decision comes up
Seeing both plans' full total cost side by side, rather than just a payback number, helps some homeowners evaluate the decision more concretely.
How this is calculated
Both paths are compared as total cost over your ownership horizon: net cost plus annual cost carried forward.
A worked example
With the defaults (flat rate: $0 net cost, $620/year; time-of-use: $50 net cost, $400/year; 10-year horizon), the time-of-use plan totals $4,050 against $6,200 for the flat rate, a $2,150 advantage for time-of-use at these defaults.
Common mistakes
A common mistake is evaluating a rate plan switch on EV charging cost alone without considering the rest of your household's electricity usage pattern.
Limitations
This compares EV charging cost only, not your whole household electricity bill under each plan.
Common questions
How is this different from the time-of-use savings payback tool?
That tool shows a simple payback on the switching cost. This one shows both plans' full total cost over your ownership horizon side by side, useful if you want to see the absolute totals, not just the savings.
Can I switch back to a flat rate plan later if it doesn't work out?
Most utilities allow switching between rate plans, though some restrict how often you can change. Check your utility's specific policy before switching.
Does this plan choice affect anything besides EV charging?
Yes, a rate plan switch applies to your whole electricity bill, not just EV charging. Consider your household's full usage pattern, not just the car.
Does this account for seasonal rate differences?
Enter your best estimate of your typical annual cost under each plan. If your utility's rates vary significantly by season, a more precise estimate would average across those seasonal differences.
What if I have solar and net metering already?
A different rate plan can interact with your solar export credit rate in ways that affect your total bill beyond just EV charging. Consider your full household picture, not this comparison alone, before switching.