Northeast Group LLC, a research and consulting firm based in Washington, DC, recently released the results from its comprehensive study, titled "United States Smart Grid: Utility Electric Vehicle Tariffs."

The study shows that, throughout the US, discounted rate plans for electric vehicle owners vary significantly.

Northeast Group uses the metric of cost of electricity per gallon of gas equivalent throughout its report, which is the same as the DoE opted to use in its eGallon calculator tool.

Northeast Group's study shows that Los Angeles Department of Water and Power customers pay $0.53 per gallon of gas equivalent, which is approximately $0.40 cheaper than the average discount programs nationwide.

On the other hand, Southern California Edison customers pay either $1.11 or $1.24 per gallon of gas equivalent, depending on which discounted rate plan is chosen.

Here are a few more results:

What's Your Rate?

What's Your Rate?

  • Pasadena Water and Power customers pay either $0.49 or $0.65.
  • San Diego Gas & Electric customers pay $1.62.
  • Hawaiian Electric Light Co. customers pay $2.51
  • Indianapolis Power and Light customers pay $0.34

According to the DoE's eGallong calculator, California’s average is $1.51 per gallon of gas equivalent, so most of the discounted rate plans that apply to California are far below that state-average mark.

All told, Northeast Group evaluated the 24 utility companies in the US that offer a discounted EV rate plan.  The posted results were based off the assumption that 70% of charging was during off-peak hours with 1,100 miles driven per month at a rate of 3 miles per kWh.

Of interest here is that, even in a single state, rates vary widely.  So, we ask of you, what's your rate per gallon of gas equivalent?  Here's the calculation used by the DoE to arrive at that number:

"We take the average distance that a gasoline-powered vehicle can drive on a gallon of gas (28.2 miles for comparable 2012 model year cars), and then calculate how much it would cost to drive the average EV that same distance."

Source: Northeast Group LLC (PDF)