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Subject: RE: [emix] Ramp intervals

I know there is another thread from this email related to DR “ramps”, but this note is focused on generation although much of it applies to DR and loads as well.


I disagree that each EMIX product needs a ramp component.  Some EMIX product may have a ramp component.


A good example is bidding into ISO markets.  The ISO accepts multi-part bids from generators and dispatches them,

Part of the bid is a ramp rate curve vs. MW output (not a WS-calendar construct ).  The output of the ISO process is hourly and five minute schedules for the generator, without any explicit WS-Calendar-like ramp.  Yes the generator does not move instantly from the level in one interval to the next in a step, but the balancing processes of the ISO accommodate this.


Most forward wholesale contracts may be scheduled hourly.  Ramping up and down from levels in one hour to next often has an assumed ramp ( from 10 minutes before the hour to 10  minutes after the hour). As Phil has said, a registration process can deal with any standard ramp assumptions.  For financial contracts the ramp can be ignored.


In automated markets it is easier to deal with schedules where the ramp is a characterized by series of shorter interval schedules.  It is also how we meter delivery as energy over an interval.  This provides standard products and contracts in each interval.  If every offer has a different ramp rate on each end markets it is harder to get liquid markets.


Also, think of the complexity in adding up a large portfolio of schedules each with a different embedded WS_Calendar ramp rate.  The final schedule with include all of the ramps, all with different durations and start times.  It is much easier to do what we do today which is a sequence of yearly, monthly, daily, hourly, 5 min schedules each of which are simple block schedules, transactions, or offers.




Edward G. Cazalet, Ph.D.

101 First Street, Suite 552

Los Altos, CA 94022


cell: 408-621-2772




From: Toby Considine [mailto:tobyconsidine@gmail.com] On Behalf Of Toby Considine
Sent: Tuesday, September 14, 2010 12:20 PM
To: emix@lists.oasis-open.org
Subject: [emix] Ramp intervals


Do we need a construction within EMIX for ramping intervals? I am tieing this to such things as the 3-part generation bids

Consider the case of a long generation cycle followed by a discrete ramp cycle. The whole shape is the electricity produced. Things don’t just shut down, there is some electricity that needs to go somewhere, and if it goes onto the grid, it must be planned for and balanced.


The large rectangle on the left is the scheduled generation period. The it may be scheduled for three hours, it may be scheduled for 1, it may be scheduled for 16. The slopey bit on the right  just comes along for the ride.

The shape above is an ugly interval.We could solve it by making an infinite number of intervals, or at least enough so that we can assume that each one was flat. I think it would be an error to recreate intro calculus within EMIX…

WS-Calendar supports separating a scenario like that above, in which the things are split into two linked intervals. It is easy to schedule the interval on the left, to any length, It is the supply of a constant amount of energy for a variable period of time, as per contract. The funny looking shape on the right, comes along for the ride; buying the left is buying the right. This occurs in many scnarios in homes / buildings / energy / …

So in Emix, we have a product, and then we have a ramp. The ramp is a predictable varying, but constant duration (probably) delivery of product. There may be ramp ups and ramp downs.


We need to include handling of ramped energy in each EMX product.



“It is difficult to get a man to understand something, when his salary depends upon his not understanding it” -- Upton Sinclair.

Toby Considine
TC9, Inc

OASIS Technical Advisory Board
TC Chair: oBIX & WS-Calendar

TC Editor: EMIX, EnergyInterop

U.S. National Inst. of Standards and Tech. Smart Grid Architecture Committee


Email: Toby.Considine@gmail.com
Phone: (919)619-2104

blog: www.NewDaedalus.com



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