How much money can driving an EV save you?

by Jay Kimball on 14 April 2017

Compared to gasoline powered vehicles, electric vehicles (EVs) cost less to drive. And in the Northwest, where much of the electricity is very clean hydropower, they have a very low carbon footprint too.

Working with electric utility Orcas Power and Light Cooperative (OPALCO), located in San Juan County, Washington, we explored just how efficient EVs are, and what kind of impact they can have on reducing TOTAL energy bills and carbon footprint.

Over half of home energy use is estimated to come from driving. As the largest source of energy consumption, replacing gasoline cars with EVs will help reduce household energy consumption, the total energy bill, and carbon footprint.

Home Energy Use

About 47 percent of San Juan County’s carbon footprint is estimated to come from transportation. So replacing fossil fuel cars with low emission EVs will reduce county carbon footprint too.

carbon footprint in San Juan County

EVs are much more efficient than gasoline cars. A typical EV can drive about 4 to 5 miles per kWh (MPkWh). To compare an EV’s efficiency with a typical gasoline car (US average 26 MPG), we convert the EV’s MPkWh and the gasoline car’s MPG to BTUs, so we are comparing with a common unit of energy. As can be seen in the comparison below, a typical EV uses about 4.8 times less energy than a typical gasoline car. That is a remarkable reduction of energy consumption.

EV Energy Efficiency compared to gasoline car

So how does that energy efficiency translate to the actual cost of driving? The chart below shows the annual cost of driving 10,000 miles each year, for EV and gasoline cars. The chart shows driving cost from 2000 to present, to appreciate the volatility of gasoline pricing versus electricity pricing. The price of gasoline comes from the EIA price per gallon of regular gasoline records. The price of electricity per kWh comes from OPALCO electric rate history.

The red line is the gasoline car, and we can see the price of gasoline is volatile compared to electricity (green line), which typically only changes once a year. We can see how the efficiency produces a major driving cost reduction for EVs. At current prices, a 26 MPG gasoline car costs about $1,000 per year to drive 10,000 miles. The EV is only $200 – one-fifth the cost of a gasoline car.

EV Driving Cost compared to gasoline car

Carbon footprint is reduced too. The chart below brings it all together, showing the cost and carbon footprint for a variety of EV and car efficiencies. The chart uses data from 2015, when gasoline prices were a bit higher. The carbon footprint for electricity is based on the footprint of OPALCO electricity.

EV Driving Cost and Carbon Footprint

If a household has two cars, at least one should be an EV. And the EV should be the first vehicle driven each day to maximize use. At our home, we share the EV, to maximize use of the lowest cost, lowest emission vehicle, and only use the gasoline car as a back up or for extended trips, such as long distance drives. We drive a 2013 Nissan Leaf, which has a range of about 100 miles. We simply plug in to a standard 120 volt outlet at the end of each day to top off the charge. It’s full up the next morning, ready to go.

EVs have been out long enough that there is a nice selection of used EVs, at prices below $10,000. If you are buying a new EV, check your state and Federal incentives. For example, in Washington state, there is no sales tax on EVs, a Federal tax credit of $7,500, and substantial rebates and low interest financing from Nissan. That takes a new $34,000 MSRP Leaf down to about $18,000. The new Nissan Leaf has a larger battery with more range. The new Chevy Bolt has about 240 mile range between charges. Tesla has a variety of range options on their vehicles.

In San Juan County, EV market share grew 55% last year. More and more drivers are discovering the low cost, clean, quiet, low maintenance driving experience of EVs.

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