Solar EV Charging Station Feeds Grid

A frequent criticism of electric vehicles (EVs) is that they’re really powered by coal, since that’s such a significant source of electricity. Leaving aside the claim’s validity (or lack thereof), you can’t use it against cars taking advantage of the new six-vehicle charging station unveiled at the Electric Power Research Institute (EPRI) in Knoxville, Tenn.

A joint effort with the Tennessee Valley Authority (TVA), this grid-connected “Smart Modal Area Recharge Terminal” uses solar panels and batteries to make and store electricity for vehicle charging, and also has the capability of sending power back to the grid. It’s a prototype, with another such station being built at the Oak Ridge National Laboratory about 10 miles away. After several months of testing, the plan is to have 125 charging spaces built in Knoxville, Chattanooga, Nashville and possibly other sites for use by researchers.

smart solar electric vehicle charging station, TVA

image via Tennessee Valley Authority

Now, it is important to note at this point these EV charging stations aren’t powerful enough to do all of their charging off the solar power system, which have a generating capacity of 2 kilowatts (kW) and battery storage of 5 kilowatt hours (kWh). As a point of reference, the 2011 Nissan Leaf has a 24 kWh-capacity battery and can charge at up to 3.3 kW per hour. But the Tennessee station’s solar component does take a bite out of what the grid needs to provide – and, in a small way, helps boost grid stability.

EPRI and TVA will be watching closely to see how people use the system.  “The data collected from these stations will help us to understand station performance, customer charging preferences and grid impact,” said Mark McGranaghan, EPRI vice president of power delivery and utilization.

Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.

1 Comment

  • Reply February 2, 2011


    If you know about inverters, you know they all emit RFI (radio frequency interference) along with power. This is also called dirty electricity, and has been linked to cancer (Prof. Sam Milham, school cancer cluster, Med. Hypoth., also nice story in Prevention Magazine). Plus your radio and TV reception will suffer (cell phones should be OK because they are up in the microwave band).

    PV is great for DC. Get a PV on your house, a regulator (non-PWM style) and charge your car that way.

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