[Oeva-list] EV charging considerations.

Steve's Account stevel at fern.com
Sat Jul 24 13:50:42 PDT 2010

gfifield at onlinenw.com writes:
> I looked at the Smart Charging doc Specifications and here is what is says:
> "The Smart Charging Dock is designed to communicate with the grid and turn
> consumers? homes into grid-connected smart charging hubs ? charging when
> energy consumption is low, and delaying the charge when energy demand is
> high.

The real winner here is the power company.

1) instead of spending your transportation fuel dollars with the 
gas station, you spend it with them.

2) The power company gets to tell you how much "fuel" you can have, and

3) The power company gets to avoid buying/using peak power generation fuel
and plant. (And more importantly, they don't have to buy/build/permit new
peak power generating capability!)

According to a recent statistic, the top 10% of the power the power
company generates, costs them 80% of the money they get from you. If
they can shave that 10%, they get to pocket the profits!

The 100 mile range quoted, depends on a specific driving profile. Let's
say, for them moment that All you driving is on the optimum range curve.

An ICE can easily do 400 miles in a day of driving. (At 55 mph, its less
than 8 hours.) In that distance there will be one stop for gas, taking
roughly 15 minutes.

An equvilent trip by EV would start out with 100 mile range, in the morning,
drive probably 80 miles, before looking for a place to charge. Stopping for
an 80% charge... (If you are number one in line, 35 minutes. If you are number
4 in line, common enough at gas stations, it's two and a half hours!). Now
you have an 80 percent charge, so you will probably start looking for a
charging station after 60 miles. Lets say for the sake of argument, you
are number one at each charging station.

80 miles, 35 minutes charge, 60 miles, 35 minutes charge, 60 miles, 35 minutes
charge, 60 miles. So.. 320 miles and about the same about of driving time.

Assuming your hotel has a charging station waiting for you, you can repeat
this the next day..

Assuming that everything works out perfectly, you can expect an extra day
on the road for every 4 days.

And that assumes you never roll up to the charging station and somebody is
already lined up for an 8 hour charge! Or even that you arn't number 4 in 
line for an 80% charge... or heaven forbid that the power company shorts
your 8 hour charge while you sleep at the hotel.

With gas stations, there is some competition for price. I'm not sure who
will set the price at a road side charging station.

You may ask "why only 60 miles?".. well.. look at your experience with an
ICE.. Do you start looking for gas with just 5 miles left in the tank? 
Especially in an area where you don't know what's available for fuel?

I'm not sure that EV charging stations will be "right on the highway".
With real estate costs being what they are, near highway interchanges, it's
likely that charging stations will be at "truck stop" sized facilities, which
are sometimes a mile or so off the road. With an EV parked for more than twice
as long as a car parks at a gas pump, the number of "pumps" dedicated to EV's
will not be nearly as large as the number of gas pumps.

In my opinion, EV's will only displace a small number of ICE miles... and 
probably very few ICE "units" because it's likely that families will have
"one of each".

With a 32 mile (each way) commute, a Leaf would be marginal at best. (Now
if they could get it to 200 miles, on a short charge!.. :-) )


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