Why the comparison matters
When a homeowner is deciding whether to install a Level 2 charger, the real question is not just what the install costs. It is whether the ongoing cost difference between home charging and public charging justifies the upfront investment. In most cases the math is not even close.
Cost per kWh: home vs public networks
Home electricity in Seattle runs roughly $0.10 to $0.13 per kWh depending on your utility (Seattle City Light or PSE). Public charging networks in the Seattle area typically charge between $0.25 and $0.45 per kWh for Level 2 AC charging, and $0.35 to $0.55 per kWh for DC fast charging. Some networks also add session fees of $1 to $2 on top of per-kWh rates.
At those rates, the cost to add 100 miles of range (roughly 30 kWh for a typical EV) breaks down as follows:
- Home Level 2: $3.00 to $3.90
- Public Level 2: $7.50 to $13.50
- DC fast charging: $10.50 to $16.50
At 12,000 miles per year, home charging saves $350 to $900 compared to public Level 2, and $900 to $1,600 compared to primarily using DC fast charging.
Annual savings at different mileage levels
Annual fuel cost depends on how many miles you drive and what mix of charging you use. Here are three scenarios for a Seattle-area EV owner with a 75 kWh battery and 3.5 miles per kWh efficiency:
8,000 miles per year:
- Home Level 2: $230 to $300
- Public Level 2: $570 to $900
- Primarily DC fast: $800 to $1,200
12,000 miles per year:
- Home Level 2: $340 to $450
- Public Level 2: $850 to $1,350
- Primarily DC fast: $1,200 to $1,800
18,000 miles per year:
- Home Level 2: $510 to $680
- Public Level 2: $1,280 to $2,025
- Primarily DC fast: $1,800 to $2,700
Payback period for a home Level 2 install
A typical Level 2 install in Seattle costs $850 to $1,600 before incentives. After the federal 30% tax credit and Washington sales tax exemption, many homeowners pay $600 to $1,100 net.
At the savings rates above, a homeowner driving 12,000 miles per year and switching from primarily public charging saves $500 to $900 annually. That means the net install cost pays for itself in 9 to 18 months in most scenarios.
For high-mileage drivers switching from DC fast charging, the payback can be under a year.
What public charging is still good for
Home charging doesn't eliminate the need for public charging. On long road trips, DC fast charging is essential. In dense urban areas where some EV owners lack home charging access, public networks are a primary option. And for apartment or condo residents without a dedicated parking space, public charging may be the only practical option.
But for homeowners with a garage or dedicated parking space, a Level 2 charger at home is almost always the most cost-effective option within the first year of ownership.
Level 1 vs Level 2 at home
Level 1 charging uses a standard 120V outlet and adds roughly 3 to 5 miles of range per hour. For most Seattle-area drivers who average 30 to 50 miles per day, Level 1 simply doesn't keep up. You can start the night at 30% and wake up at 55%. That is fine for occasional use but not for daily drivers.
Level 2 charging uses a 240V circuit and adds 20 to 35 miles of range per hour depending on the charger and vehicle. Most drivers can fully charge an empty 75 kWh battery in 7 to 10 hours, meaning any car left to charge overnight is full by morning.
The practical difference: Level 1 means managing your charge carefully. Level 2 means your car is always full in the morning.
Smart charger features and off-peak rates
Some utilities offer time-of-use rates with lower prices during off-peak hours (typically overnight). Seattle City Light and PSE both offer residential time-of-use options. A smart charger like the ChargePoint Home Flex or the Emporia EV charger can be programmed to charge only during off-peak windows, further reducing your home charging cost.
If you are on a time-of-use plan with overnight rates around $0.07 to $0.09 per kWh, the cost per 100 miles drops to $2.10 to $2.70, making the public charging premium even larger by comparison.