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Subject: RE: FW: [emix] Power storage strategies
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Francis With respect to the
Transactional Energy paper it is focused on the loosely coupled interactions as
you suggest. The paper offers no
suggestion on how "tightly coupled interactions with in a building or campus
might interact. However as David
Holmberg suggested earlier in this thread: Ed Edward G. Cazalet, Ph.D. 101 First Street, Suite 552 Los Altos, CA 94022 650-949-5274 cell: 408-621-2772 From: Frances Cleveland [mailto:fcleve@xanthus-consulting.com] Folks
- Gale, -------- Original Message -------- Subject: RE: FW: [emix] Power storage strategies From: "Ed Cazalet" <ed@cazalet.com> Date: Tue, April 27, 2010 3:25 pm To: "'David RR Webber (XML)'"
<david@drrw.info>, "'Considine,Toby (Campus Services IT)'"
<Toby.Considine@unc.edu> Cc: <fcleve@xanthus-consulting.com>, "'Phil
Davis'" <pddcoo@gmail.com>, <Toby.Considine@gmail.com>,
<emix@lists.oasis-open.org> To continue this excellent discussion. First, for the benefit of Francis below is a link to White
Paper on Transactional Energy that, in part, deals with ancillary services in a
way that I think levels the field between generation, storage and loads as
providers of ancillary services. The idea is to facilitate energy
transactions on shorter intervals including 4-second intervals for frequency
regulation. Download Document: With respect to David's quest for simplicity, I think we are
closer than it might seem. David wrote (italics) : So my real time scenario would run something like this: 1) Power source queries grid for status of existing
available storage devices with surplus capacity 2) From responses and my available power - I commit with a
couple of them to push power to them - to determine this I just need ROM
calculations that tell me they can absorb the power at the rate I'm generating
it. - their availability should be immediate, or
time when to commence charging - indicate status update refresh period for 20%
change in stored power or full - depending on anticipated storage rate - this
you can calculate - either from history of previous service to that device - or
device itself can give you estimate - if you are off by a % it won't be a big
deal. 3) Commence power distribution 4) Receive regular status updates from devices of their new
storage level and remaining capacity. 5) Compute decision - continue power supply or loop back to
1) 6) If no storage devices available - then scale back power
generation - until receive storage notification from device available. My revision. 1) Power source queries storage providers or brokers
for quotes to store (buy) 25 MW per hour from 2 am to 5 am ( 100 MWh) 2) Generator accepts the best quote of $25 per MWh. 3) Generator requests quote to store another 100 MWh for the
same hours. 4) Storage providers are full and provide no further quotes. 5) Generator scales back generation to store only 100 MWh. Note your example talked about where the power was stored
and not what the generator got back ( money or energy) and when. My
example assumes the generator gets money for the stored energy. Perhaps a better transaction with storage is as
follows: Generator requests a quote for storing 100 MWh from 2 am to 6 am
and drawing 80 MWh from 2 pm to 6 pm, ( accounting for a rough 80% round trip
storage efficiency). The storage provider might quote $50 per MWh stored for this
service. Ed Edward G. Cazalet, Ph.D. 101 First Street, Suite 552 Los Altos, CA 94022 650-949-5274 cell: 408-621-2772 From: David RR Webber (XML) [mailto:david@drrw.info]
Sent: Tuesday, April 27, 2010 8:02 AM To: Considine,Toby (Campus Services IT) Cc: fcleve@xanthus-consulting.com; Phil Davis;
Toby.Considine@gmail.com; emix@lists.oasis-open.org Subject: RE: FW: [emix] Power storage strategies All, I'm still urging for keeping this really simple! From the perspective of the supplier for the surplus power
to push to the storage device - how much precision do you really need!?!?
Frankly I really don't need to know much about the device beyond how much
capacity to a ROM (Rough Order of Magnitude). Why over engineer this - if
you can use simple tracking messages to see how you are progressing?
Remember when a 5Mb hard drive was a big deal?! Expect market to drive
demand for low cost buckets of storage in future... So my real time scenario would run something like this: 1) Power source queries grid for status of existing
available storage devices with surplus capacity 2) From responses and my available power - I commit with a
couple of them to push power to them - to determine this I just need ROM
calculations that tell me they can absorb the power at the rate I'm generating
it. - their availability should be immediate, or
time when to commence charging - indicate status update refresh period for 20%
change in stored power or full - depending on anticipated storage rate - this
you can calculate - either from history of previous service to that device - or
device itself can give you estimate - if you are off by a % it won't be a big
deal. 3) Commence power distribution 4) Receive regular status updates from devices of their new
storage level and remaining capacity. 5) Compute decision - continue power supply or loop back to
1) 6) If no storage devices available - then scale back power
generation - until receive storage notification from device available. What I would anticipate is that scenario 6) is really about
always having enough storage capacity available to balance demand. From our XML perspective - so long as our simple message
designs contain enough information to drive the decision making - we don't need
more. E.g. we want minimalistic message design. People will always
think of more and more exotic information that can be added - we want to
strongly resist that - and require ONLY the information needed to drive a
working process - nothing more. Remember - the messages do NOT need to
contain information that can be obtained elsewhere. Otherwise you end up
with a standard that is extremely tough to implement - and then even worse to
have consistent interoperability across vendors. Plus break the messaging
down into small discreet purposes. For example - I do NOT need to send
device profile but once - first time device is available. DW Thanks, DW -------- Original Message -------- Subject: RE: FW: [emix] Power storage strategies From: "Considine, Toby (Campus Services IT)"
<Toby.Considine@unc.edu> Date: Tue, April 27, 2010 9:44 am To: Phil Davis <pddcoo@gmail.com>,
"Toby.Considine@gmail.com" <Toby.Considine@gmail.com>,
"emix@lists.oasis-open.org" <emix@lists.oasis-open.org> Cc: "fcleve@xanthus-consulting.com"
<fcleve@xanthus-consulting.com> Well, I think you are correct. The discussion of the performance attributes or an offering
that we skated around last month are really about ancillary services…. Time to respond after request? Ramp time after response? Minimum response Maximum response Maximum sustained response (define sustained) Cycle time… These are all aspects of being able to fit DR to ancillary
markets, not just to “traditional†DR. As most of them are some sort of
“meet or exceed†expectations, the same DR could be offered to different
markets. Alternately, the building owner could easily see how system augmentation
to improve a performance metric would allow the building to play in a more
lucrative market… tc "If flies are allowed to vote, how meaningful would a
poll on what to have for dinner be, and what would be on the menu?"
- Unknown Toby Considine Chair, OASIS oBIX Technical Committee Co-Chair, OASIS Technical Advisory Board Facilities Technology Office University of North Carolina Chapel Hill, NC Email: Toby.Considine@
unc.edu Phone: (919)962-9073 blog: www.NewDaedalus.com From: Phil Davis [mailto:pddcoo@gmail.com]
Sent: Monday, April 26, 2010 9:10 PM To: Toby.Considine@gmail.com; emix@lists.oasis-open.org Cc: fcleve@xanthus-consulting.com Subject: RE: FW: [emix] Power storage strategies Frances is right of course. John Kueck at Oak Ridge
feels there will come a time that the demand side is the total resource for
reliability and regulation. Though I'm not sure of the 100% level, there
are aspects of ancillary service participation that properly implemented and
managed would (I think) be more appealing to commercial buildings than would
traditional DR programs. I have been assuming, perhaps wrongly,
that our discussions energy communications would include support of ancillary
services. Is this correct? Thanks! Phil From: Toby Considine [mailto:tobyconsidine@gmail.com] On
Behalf Of Toby Considine Sent: Monday, April 26, 2010 3:35 PM To: emix@lists.oasis-open.org Cc: fcleve@xanthus-consulting.com Subject: FW: FW: [emix] Power storage strategies I forwarded this conversation to Frances Cleveland, who is
working on electrical standards for storage management (the complicated process
we are trying to stay out of). Thee followed back with a an interesting analogy
of the more valuable types of response dictated by ramp time, response time, et
al. 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: Toby.Considine@gmail.com Phone: (919)619-2104 blog: www.NewDaedalus.com From: Frances Cleveland [mailto:fcleve@xanthus-consulting.com]
Sent: Monday, April 26, 2010 3:06 PM To: Toby.Considine@gmail.com Cc: emix@lists.oasis-open.org Subject: Re: FW: [emix] Power storage strategies Toby
- Just
to add to the mix, I did not see "ancillary services" in this
discussion - these are services like var management, frequency deviation
mitigation, load following, etc. These are huge issues for utilities, and just
like derivatives are often more "valuable" than stocks in the stock
market, are often of more value to the utility than just energy. If
I can't send this directly to the emix list, please forward ..... Frances At 11:52 AM 4/26/2010, Toby Considine wrote: Sharing the conversation that broke out today in EMIX… "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: Toby.Considine@gmail.com Phone: (919)619-2104 blog: www.NewDaedalus.com From: Ed Cazalet [mailto:ed@cazalet.com]
Sent: Monday, April 26, 2010 2:50 PM To: 'Phil Davis'; 'David RR Webber (XML)'; Toby.Considine@gmail.com Subject: RE: [emix] Power storage strategies David, Thanks for getting an informative debate going. I assume that you are suggesting that storage can be
generically modeled as a device with a MWH capacity, a power ratio for both
charge and discharge of say 4 MW per MWH (4 to 1 ratio) and a current state of
charge (% of the MWH energy capacity) with some updating of these parameters as
necessary. Further, I assume you are suggesting that this
information be used by other parties ( and possibly the owners ) to
dispatch the storage. However you have not mentioned how third parties
would be charged or contract for the use of the storage. Keeping with your idea to keep the storage model simple. we
would need at least also specify a round trip efficiency of storage devices
since this efficiency ( MWH Out / MWH in) can vary between 50% and over 90% for
various storage technologies. Additionally, some compressed air energy
storage devices (CAES) also require natural gas as an input energy source in
addition to electric energy. ( Note: round trip efficiency is also a function
of state of charge and rate of charge and discharge, but let's say we ignore
that for simplicity.) A fixed power ratio is also problematic for many storage
devices. Many batteries have asymmetric charge and discharge ratios, so
that we would need to specify different ratios for charging and
discharging. Additionally, many batteries are able to charge or discharge
at high rates for short time periods or when they are not near full or not near
empty and then at much lower rates on a sustained basis. Another critical parameter is response ramp rate. Some
devices such as batteries and flywheels have an almost instant response whereas
pumped hydro and CAES have a much slower response, limiting their value for frequency
regulation. Battery life is also an issue. A battery typically
might be able to discharge a fixed number of MWH over its life depending
somewhat on how charging and discharging is done. So charging and
discharge for small economic benefit must be avoided to save the battery for
situations where such use has high value. What information we provide about storage also depends on
what side of the plane of control (energy services interface) we might be
on. On the storage device side of the interface, the physical models that
you suggest may be useful, however the need to over simplify is less. On the inter domain side of the interface communicating even
a simplified storage model to other parties and then figuring out how to
dispatch that storage in coordination with generation and load is
challenging. US ISOs are currently working on tariffs and software to
allow limited energy devices such as flywheels and batteries with 15 to 30 min
of storage to participate in frequency regulation markets. It is a
significant software and market design challenge to recognize the limitations
of storage (which vary by device type) in comparison to generation while at the
same time given storage the benefit to the system of the much faster response
of storage in providing regulation services. And most have not yet fully
implemented the economic dispatch of deeper storage devices into their economic
dispatch and locational pricing models. If avoiding over complication by engineers and striving for
simplicity is a goal, then I recommend the pure simplicity of Transactional
Energy outside of the plane of control of specific devices. What is done
inside the plane of control is another matter, where the specifics of each
device are much easier to accommodate. With Transactional Energy a storage owner can make or accept
an offer to buy MWH at a given rate and at given low price at night or when the
wind is blowing hard. The amount and price will depend on many factors
such those we have discussed above. The storage owner can also make or
accept an offer to sell energy at a higher price in the afternoon or when the
wind is not blowing. A party could perhaps simultaneously enter into a
transaction to sell in the morning and buy in the afternoon from the storage
owner. This is real simplicity and it is the way we buy and sell almost
everything else in our life.. Perhaps as both an economist and an engineer, I can
revise your statement " Never under estimate an engineer's ability to add
complexity! to say, "Never underestimate the ability of an
economist's market to make simple what an engineer can make complex!" Ed Edward G. Cazalet, Ph.D. 101 First Street, Suite 552 Los Altos, CA 94022 650-949-5274 cell: 408-621-2772 From: Phil Davis [mailto:pddcoo@gmail.com]
Sent: Monday, April 26, 2010 8:27 AM To: 'David RR Webber (XML)'; Toby.Considine@gmail.com Subject: RE: [emix] Power storage strategies Actually, GE announced such a system last week and is hiring
400 people in Atlanta to staff the new business. It's a substation level
product. Also, I have spoken personally with people at Hitachi and
Samsung who are testing a 1 MW battery. Such a battery from another vendor
is in test operation behind PJM's main offices. So local here takes on a new
meaning depending on whether it is truly behind the customer meter, or behind
the distribution grid meters (substations and the like), or on a transmission
system. Theoretically, batteries of this size could replace generators
used for voltage or frequency support. Phil Davis From: David RR Webber (XML) [mailto:david@drrw.info]
Sent: Monday, April 26, 2010 10:58 AM To: Toby.Considine@gmail.com Cc: emix@lists.oasis-open.org Subject: [emix] Power storage strategies Toby, It occurs to me that local storage can potentially play a
role here - depending on its efficiency of course. One can anticipate
that future technology will offer higher % there - especially if market forces
drive that equation. Therefore - a future system could offset power surges by
drawing on locally stored resources that were captured during off-peak or
excess capacity. In fact such a system may notify suppliers that they can
"push" excess power to local storage at some pre-determined cost
point - and of course also need to indicate that the storage facility is at a
certain % level, or if empty - accept units at a higher cost rate. DW ________________________________________________________________________ This email has been scanned for SPAM content and Viruses by
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****************************************** * Frances M. Cleveland * Xanthus Consulting International * 369 Fairview Ave * Boulder Creek, CA 95006 * Tel: (831) 338-3175 * Cell: (831) 229-1043 * fcleve@xanthus-consulting.com ******************************************
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