David,
Talk to the operator of a large plant with heavy electric draws, how
they think about
load leveling.
I know of plants where they bought specialized equipment to sequence the
different
draws of startup of electric motors, just to reduce the peak draw as
their bill was
more determined by the maximum peak power that they would draw
instantaneously
during any time in a month, than the total electric consumption.
Reason is simple: the power plant needed to have that much power "on
tap"
even though it was not used 99.999% of the time.
So, starting different motors out of sequence and even turning some
loads OFF
deliberately just for the few seconds that the largest electric motors
were starting,
saved them big bucks, just from reducing their peaks.
And a big heater or electrolyzer that is turned off for a few seconds
makes no difference
in the result of that process other than that it may take a few seconds
longer for the
end result, but there are immediate savings.
And that was before battery storage was very common and efficient, today
they may opt
to start motors entirely from stored power.
I think that fast charging with load leveling, whether by battery
storage or by throttling
all stations a little if all try to draw max at the same time, until one
or more no longer
takes max power and the majority of the power can flow to a fewer nr of
stations,
certainly makes sense to reduce both cost of the connection as well as
pek power bill.
Note that many fast charging stations today need a commercial power
connection
because the 100+ Amps at around 400VDC means over 40kW continuous so it
is typically c
connected at 480V. EMW has developed a battery backed fast charging
ChadeMo station
that can live off the 12kW available from an RV outlet (240V 50A) and I
expect that just
the savings in connection required (residential instead of commercial)
makes up for the
investment in the battery bank.
Cor.

-----Original Message-----
From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of EVDL
Administrator via EV
Sent: Monday, November 20, 2017 10:05 AM
To: Electric Vehicle Discussion List
Cc: EVDL Administrator
Subject: Re: [EVDL] EVLN: Fisker's 3D electrode li-ion promises 500Mi
EV& 1min recharge

On 20 Nov 2017 at 9:38, Cor van de Water via EV wrote:

> In my book charging a 40kWh battery in 1/60th hour (one minute) to 80%

> means 40 x 0.8 x 60 = 1920 kW, almost 2 Megawatt.

Thanks, absolutely correct.  I got unconscionably careless with my
powers of 10.  That shouldn't have passed the sniff test here.  Sorry.

For sure, 2 megawatts is much more manageable than 2 gigawatts, though
10 or
20 megawatts to run an EV "filling station" is still a pretty
substantial amount of power.  

Using a battery as a load leveler would certainly help, but also would
add operating expense.  It also makes me think about the PV folks who
tout the benefits of grid intertie for leveling THEIR loads.  :-)

David Roden - Akron, Ohio, USA
EVDL Administrator

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