Agree
that we should be generic. The real data of significance is
available rate of charge/discharge. A traditional generator can go
indefinitely, and traditional demand response (kinda sorta) maintains a steady
state for a defined period of time. Depending on type, storage can behave
similarly, one exception being batteries. As batteries charge or
discharge, the rate at which they do so tends to change, as does the max voltage
available. Of course we (and dare I say others) make marvelous devices to
mitigate the impact of this, but the truth is that batteries never deliver rated
capability for the entire span of a charge/discharge cycle.
So the
question is whether this should be part of the communications, or whether the
grid model learns this via statistical inference from meter data over
time. If the latter, then nothing overt is needed in the comm
record. If the former, then I am at the limit of my ability to expound on
this, having attended liberal arts institutions.
Phil
From: Toby Considine
[mailto:] On Behalf Of Toby
Considine
Sent: Monday, April 26, 2010 12:44 PM
To: 'David
RR Webber (XML)'; 'Edward Cazalet'
Cc: ;
'Phil Davis'
Subject: RE: [emix] Power storage
strategies
Push?
Will
that work as well as the Push technologies that are perennially the next wave on
the ‘net
The
correct push is appropriate pricing.
The
correct measure of battery efficiency vs afternoon scarcity is
pricing.
tc
"If
something is not worth doing, it`s not worth doing well" - Peter
Drucker
Toby
Considine
TC9, Inc
OASIS
Technical Advisory Board
TC Chair: oBIX &
WS-Calendar
TC
Editor: EMIX, EnergyInterop
Email:
Phone:
(919)619-2104
http://www.tcnine.com/
blog:
www.NewDaedalus.com
From: David RR Webber
(XML) [mailto:]
Sent: Monday, April 26, 2010 12:36
PM
To: Edward Cazalet
Cc: ;
; 'Phil Davis'
Subject: RE: [emix] Power
storage strategies
Ed,
Never
under estimate an engineers ability to add
complexity!
What
is wrong with the simple notion of % full and capacity total in MW and storage
ratio?!?! Completely agnostic to the storage device
characteristics!!!
If I
know the storage is 60% full and has a total capacity of 100 MW - and a default
ratio of power to storage of 4:1 then I know I can push 40 x 4 = 160 MW at the
device to fill it. Plus if device is sending out updating in intervals - I
might send it 100MW - then it says it is 85% full - so I adjust
accordingly.
Once
it is full it sends "Stop!" - simple!
If
you want to get clever on your backend systems - you may track actual storage
ratio achieved compared to default - or the device can adjust that
itself.
Thanks,
DW
