Calculating an EV’s True Energy Costs

Sep 25, 2017 | EV Chargers, Learning Resources, Renewable Energy News, Solar Energy

In the market for an EV?

Here’s how to understand your energy fuel savings, and the true cost of charging your EV.

Example: If you buy a Nissan Leaf, charge at home, and drive 1,000 mi/ month, your electric bill will increase by $62/month in added use.

HERE’S HOW TO CALCULATE:

1. Start with the electric car’s energy consumption rate, which is expressed as kWh per 100 miles. The average is 31kWh/100 mi.  All EV window stickers base the MPGe on a national average of 12¢ per kWh. DO NOT USE THIS number. It is not representative of what YOU will pay.

2. Then figure out what you pay for electricity. If you are a PG&E customer living in the central coast, your average cost per kWh for electricity to charge your EV is 20¢/kWh.

3. Multiply 20¢/kWh by the EV models stated kWh/100 miles.

The sum is your cost per 100 miles driven.

____________________________________________

CURRENT EV MODEL kWh/MILES:

Hyundai Electric = 25 kWh/100 mi

BMW i3 = 27 kWh/100 miles

Scion iQ = 28 kWh/100 miles

Chevy Bolt = 28 kWh/100 mi

Chevy Spark = 28 kWh/100 mi

VW eGulf = 28 kWh/100 mi

Honda Fit = 29 kWh/100 miles

Fiat 500e = 29 kWh/100 mi

Mitsubishi = 30 kWh/100 miles

Nissan Leaf = 31 kWh/100 mi     AVERAGE

Ford Focus Electric = 32 kWh/100 mi

Smart ForTwo = 32kWh/100 mi

Kia Soul Electric = 32 kWh/100 mi

Tesla Model S = 32 kWh/100 mi

Mercedes B-Class Electric = 40 kWh/100 mi

Toyota Rav 4 EV = 43 kWh/100 mi

____________________________________________

LET’S CALCULATE.

The Nissan Leaf is rated at 31 kWh/100 miles.

Average kWh energy costs = 20¢

____________________________________________

31 x 20¢ = $6.20 per 100 mile charge

$6.20 / 100 miles = 6.2¢ per mile electric costs.

The Nissan Leaf costs 6.2¢/mile to drive.

____________________________________________

COMPARE TO A GAS VEHICLE.

Driving a gas vehicle that gets 21 MPG, with gas at $3.50/gallon, the gas vehicle costs 16.6¢ per mile to drive. Driven 1,000 miles/month, the gas vehicle costs $167/month in fuel costs.

Gas Vehicle = $ 167/month in fuel costs

Nissan Leaf EV = $62/month electricity costs

SAVINGS = $105/month

home EV charging station

SAVINGS MORE WITH AN EV PLUS SOLAR

Here’s where solar PV and battery storage can really magnify your savings.

Solar electric currently costs less than 8¢ per kWh to generate,

well under the average utility rate of 20¢ per kWh.

____________________________________________

8¢ x 31 = $2.48 per 100 mile charge

$2.48 / 100 miles = 2.5¢ per mile electric costs.

____________________________________________

If you drive the average of 1,000 mi/month, the Nissan Leaf

will cost you $25/month in electricity.

____________________________________________

Gas Vehicle = $167/month fuel costs

Nissan Leaf EV w/ solar = $25/month electricity costs

SAVINGS = $142/month

News Categories