Public Charging Price Breakeven for a Home Charger
Rather than testing one home-vs-public comparison at one assumed public price, this solves backward: given the charger's cost and your annual usage, what effective public charging price makes a home charger clear your target payback.
At your inputs, the electricity rate that hits a 5-year payback is $0.107/kWh.
| Required electricity rate | $0.107/kWh |
|---|---|
| Payback at your actual entered rate | 3.0 years |
- This uses planning estimates you entered, not a contractor quote or guaranteed savings.
- It solves for the electricity rate that meets your target payback; it does not predict future public charging prices.
What this also tells you: Your actual entered rate gives a payback of 3.0 years; the rate above is only the threshold for your stated target, not a forecast.
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
Public charging prices vary widely by network and location, and this isolates exactly how expensive public charging needs to be, given your usage, before a home charger clearly pays for itself.
How this is calculated
Given your charger's net cost, expected annual kWh you'd otherwise charge publicly, and a target payback period, this solves for the effective price per kWh that makes those three numbers work out exactly.
A worked example
With the defaults ($1,600 net cost, 3,000 kWh/year, 5-year target), the required effective price is $0.107/kWh above your home rate. If public charging in your area regularly costs more than that premium over your home rate, a home charger clears your target payback comfortably.
Common mistakes
A common mistake is comparing a home charger's payback against a single low public-charging price point rather than your actual typical usage across the networks you'd realistically use.
Limitations
This does not model public charging price changes over time or different network pricing tiers.
Common questions
How do I find my effective public charging price?
Check the network's per-kWh or per-minute pricing you actually pay, converted to an effective per-kWh rate if billed by time. Your own charging session history, if available through an app, is the most accurate source.
What if public charging is cheaper than the threshold?
That means a home charger does not clear your target payback purely on avoided public charging cost at your usage level, though convenience may still justify it.
Does this account for DC fast charging specifically?
Enter whatever effective price reflects your actual public charging mix, DC fast charging or Level 2, since that determines your real baseline cost.
Does this differ by charging network?
Yes, effective pricing varies significantly between networks and even between DC fast and Level 2 stations on the same network. Use a blended average across whichever networks you actually use, not a single network's advertised rate.
What if public charging prices in my area are trending upward?
This tool holds price constant to solve for today's threshold. If you expect prices to rise, that strengthens the case for a home charger beyond what this snapshot shows.