Frequently Asked Questions
| Assumptions

Should I install a Level 1 or Level 2 Charger?

A Level 1 Charger is included as part of the vehicle purchase. Level 1 Chargers plug into standard household outlets. Level 2 Chargers are purchased separately and must be installed by a licensed electrician. The power rating shown is the maximum level 2 rating available for the selected vehicle.

Electric Vehicle Energy Costs

First, the electricity use for the user’s home is calculated using information provided about their electric bill. Energy costs with a conventional vehicle are comprised of the home electric bill plus the cost of fuel for the vehicle. To calculate energy costs with a plug-in vehicle, home electricity use and vehicle electricity use are combined into one bill. Conventional fuel costs (i.e., Gasoline) are also included for plug-in hybrid vehicles.

Customer Energy Use

An hourly consumption profile is generated from the average monthly bill information provided. Statistical average profiles published by the electric company are used to calculate an hourly consumption profile for the user based on their electric rate plan and average monthly bill amount. This assumption will be reasonably accurate for the majority of users, but those with unique profiles, such as users with time-of-use rates, may experience notable differences.

Environmental Savings

Environmental calculations are based on state level EPA emission factors from the Emissions & Generation Resource Integrated Database (eGRID) . Emissions are calculated for both the electric vehicle and conventional vehicle.

Weekday vs. weekend miles and extended trips

Mileage is referenced in terms of average daily driving and annual miles so that users can adjust to account for typical commuting as well as one-time, longer trips.

Operations and Maintenance

Maintenance and repair costs are calculated using methodology published by Argonne National Laboratory (ANL) in its 2021 report: "Comprehensive Total Cost of Ownership Quantification for Vehicles with Different Size Classes and Powertrains". The cost of maintenance (regular service to prevent damage and prolong vehicle life) is calculated on a dollar per mile basis for each powertrain type, determined using national average costs for maintenance items and average maintenance service schedules. The cost of repairs (work to fix malfunctioning parts that inhibit the use of the vehicle) is calculated on a dollar per mile basis according to MSRP, adjusted for powertrain type and vehicle class. The dollar per mile rate for repairs increases every 15,000 vehicle miles travelled (VMT) to account for increasing repair costs as vehicles age. However, it is assumed that no repair costs are incurred for the first 36,000 VMT to reflect coverage provided by a standard zero-deductible warranty. Electric vehicles are expected to be cheaper to maintain and repair than comparable gasoline vehicles due to the absence of engine oil, timing belts, oxygen sensors, spark plugs and other components.

Vehicle MSRP

MSRPs are estimates based on data from and vehicle manufacturer websites.

Charging Station Map

Charging station data is compiled using data from the Alternative Fuels Data Center.

Cost of Vehicle Charger

There is no installation cost associated with a Level 1 Charger. The default cost for installing a Level 2 home charging station is $2,200. This value can be adjusted by the user. The default value is based on data from Energy Star® and includes labor, materials, and permitting.

Federal Incentives provides information on the Plug-In Electric Drive Vehicle Credit and the Residential Energy Efficient Property Credit (applicable to estimates that include the installation of solar panels).

State Tax Credits and Rebates

The CA state incentives are income based. The estimate assumes the standard $2,500 rebate available to consumers with incomes below the higher-income cap and above the low-and moderate-incomes eligible for increased rebates. More information on the CA Clean Vehicle Rebate Project may be found at