Personal Vehicle Calculator

An example vehicle calculator was developed for the 2021 Power Plan. The tool estimates the cost of ownership and quantifies the emissions for selected electric and gasoline powered personal vehicles – VehicleCalculatorTool.xlsx. 

This is an example comparing the 2020 model version of the Chevy Bolt EV hatchback with a similar gasoline-powered car, the Mazda 3 hatchback. Some key vehicle specs are outlined in the table below.

Vehicle Specifications - Hatchbacks

The values for many of the following input variables can be changed in the calculator tool. For this example, it is assumed the owner purchases the vehicle new, with a 15% down payment and a 60-month term car loan. For the electric vehicle, the owner also purchases charging equipment ($1,765), and qualifies for a federal tax credit of $3,750. The federal tax credit the owner receives for an electric vehicle purchase could range from $0 to $7,500, depending on the specific tax circumstances of the owner. 

The fuel prices are assumed to be an average price in the region for gasoline and electricity; they are initialized at:

• Gasoline $2.55 per gallon
• Electricity $0.084 per kWh

In this example, at the 5-year milestone, the cost of ownership of the electric vehicle is around $2,500 higher than the gasoline vehicle. This is due to the higher sticker price and resulting higher loan payment. However, by year 10 the cumulative cost of ownership for the electric vehicle is $3,400 less than that of the gas-powered vehicle, and by year 15 it is $9,800 less. This calculation demonstrates the clear advantage that the electric vehicle has in terms of annual cost for fuel and maintenance. Due to the better fuel efficiency and more simple maintenance, the annual fuel cost in year 5 for the electric vehicle is 28% that of the gasoline counterpart and annual maintenance outlays are 70% of the gas vehicle.

Cumulative Cost of Ownership for Hatchbacks

In addition to fuel and maintenance cost advantages, another benefit an electric vehicle has is the reduced greenhouse gas (GHG) emissions related to their use, expressed in kilograms of carbon dioxide equivalence – CO₂e. In our example, with the gasoline-powered vehicle traveling 12,000 miles per year with a fuel economy of 30 miles per gallon, the annual GHG emissions at the tailpipe translate to 3,525 kg CO₂e. 

For the electric vehicle, traveling 12,000 miles at a fuel economy of 3.503 miles per kWh, the annual emissions associated with electricity generation can be estimated at 420 kg CO₂e. This is calculated with a power generation emission rate of 0.12 kg CO2e/kWh. Hydro, wind, and solar generated electricity is free from emissions, but the Northwest still relies on fossil fuel power to fill in gaps.

The power generation emission rate may be estimated for each year from our electric price modeling work that was done for the power plan. This value declines over time as the regional coal plants close. An alternative single year emission rate can also be derived from the EIA reported power generation emissions from the four Northwestern states in 2019.[1]  

Over the course of 15 years, the emissions from the gasoline vehicle are 11 times higher than the emissions associated with the electric vehicle.

Cumulative Vehicle GHG Emissions for Hatchbacks

If battery packs improve in efficiency and drop in price, the advantage for going electric becomes even more clear. The tradeoff in vehicle range between gas and electric remains; however, an extensive buildout of electric charging infrastructure might alleviate some range anxiety for electric vehicle drivers.

The following figures show the same analysis comparing an electric small SUV with a gasoline counterpart.

Vehicle Specifications – Small SUV

Cumulative Cost of Ownership for SUV

Cumulative Vehicle GHG Emissions for SUVs

[1] https://www.eia.gov/electricity/data/emissions/