At the recent RETECH2012 conference in D.C. – co-sponsored by ACORE, which is an organization with which NECA is associated – Don Karner of ECOtality was one of numerous speakers.
I interviewed Don in May 2011 (details here); he’s a guy with 15 years of electric utility experience, which gives him a unique perspective on the EVSE business.
Nearly 17 months passed between that interview and RETECH – not very great times for the company’s stock (symbol ECTY), as you can see from this two-year price chart:
ECOtality, as you might know, is one of two primary contractors for the U.S. DOE in its efforts to subsidize public charging stations. See The EV Project website for more.
Powerful chargers, powerful problem
Karner’s D.C. talk was about, of all things, DC Power! Of the 8,000-plus public charging stations in which ECOtality has been involved (and 13,000 total that it has been contracted to put in place), he said, roughly 200 were to be DC Fast Charging outlets.
What’s the problem? The way utilities charge for electric power. As you probably know, beyond the per-kWh charge (consumption), there is also a demand charge (for capacity the utility needs to serve everyone). If your demand peaks at 50 kW for one “sliding” 15-minute window . . . your demand charge is assessed at the 50-kW level (whatever that is where you’re located) – for the next 12 months.
Guess what? A DC Faster Charger is going to provide 50 kW. That’s the way it can charge a battery-only EV to 80% of its battery capacity in 30 minutes!
However, the economics do not work. He used an example of the monthly cost to a DC Fast Charging facility owner in Southern California: $1,460 a month in demand charges alone.
That’s a stiff overhead hurdle (don’t forget, there are per-kWh charges, too . . . and the cost to build the thing, promote it, operate it, and so forth).
Solution? Maybe it’s energy storage
What’s the solution? In-ground Battery Energy Storage at the DC Fast Charge facility, Karner said. He used the example of a Nissan Leaf (which has a 19.8 kW battery capacity).
At 50 kW, it would take 32 minutes to “fuel” the Leaf’s batteries to 90% of capacity. How do you shave the demand charge? You used the in-ground batteries to provide some of the “fuel” to the Leaf, he said – and, each day, the in-ground batteries are “refilled” several times (hopefully at special lower rates from the utility).
Is this working anywhere? ECOtality is testing the concept right now. “The economics dictate that it’s all about the [in-ground] batteries,” he said. You have to buy them for the DC Faster Charging facility. How long will they last? How many “refills” will they be able to accept?
Tests are being conducted with an NiMH battery, four of the Lithium variety, and two “advanced” lead-carbon batteries. Karner indicated the results were good so far, but the tests took place at a 77-degree (Farenheit) environment. Next up: Testing will be conducted in a hotter place (Phoenix), to see what happens.
“Our experience with batteries and high temperatures,” Karner said, “ . . . is not very good.”