Posted on 07/09/2002 2:46:05 PM PDT by socal_parrot
On-target, gramps. Gotta get the word out. CBS-News (surprise) did a segment on this topic.
And my airco is set to 70, and I have a bunch of servers running, plus the TV with the all star game, and the kegerator, and.....
Up your Dim-Bulb Davis!
I think (and I am speculating) that I understand what you are saying. I also think that maybe I can put a few things in perspective.
There is an article on what Alerts, Warnings and Emergencies mean. It can be found at the following locaction
From what I read and understand, the graphs that show the available generation from which you calculated "reserves" are not the "available generation" The graph of available generation from what I understand, has been "artificially reduced or lowered" by 3%. Actually the key definitions are as follows:
Available Resources*: The current forecast of generating and import energy resources available to serve the demand for energy within the California ISO service area. Total Resources is comprised of dependable generation less outages and unavailable OFs, plus the expected imported supply. Available resources is equal to Total Resources less a 3% reserve margin*. (Calculation is detailed below.)
A 3% reserve ensures the California ISO's ability to respond adequately to an unanticipated emergency. In order to protect the integrity of the Grid, the California ISO may declare a Stage Three Emergency when the system's Operating Reserver is forecast to be at or below 1.5% or less than the largest contingency within the service area (estimated to be 3%)..
So during the 3PM hour when the total generation (not discounted for reserves) exceeded load by only 694 MW or 1.6% of total generation, your question is why was only a Stage 1 Emergency declared?
I think we can both agree that probably they were on the ragged edge of a Stage 3 Emergency. The details also show that Total resources increased during the 4 PM hour. Things collapsed pretty quickly and it is clear that the ISO does not have a decent forecasting process.
According to the SOP's, should the ISO have declared Warnings the day before and Alerts the hour before? Yes! However, again, I don't think they have a good enough forecasting process to do that. Does this mean that the ISO shouldn't start a crash course in forecasting techniques. Nope, they should be able to do a lot better.
Could a single large machine fail and exceed 1% (435 MW) or 1.5% (652 MW) of the total generation which was 43504 MW? Yes, there are some large Nuc's that could have dropped that much load in a scram or turbine failure mode.
Does this mean that a Stage 2 or 3 Emergency should have really been called when a Stage 1 Emergency was called instead? That is an excellent question!
If that was your question instead of why wasn't a Stage 2 or 3 Alert called, I think you have a question that should be put to the Cal ISO. I would speculate that the answer they will give is that very early into the 3PM hour they placed an emergency order with the Bonneville Power Administration (or BC Hydro or other large power producer) to provide a significant enough increase in Total and available generation to know that they would not need to declare a Stage 3 Emergency during the 4 PM and later hours. None-the-less, I'll bet somebody was sweeting blood during the last half of the 3PM hour to make sure a power plant didn't go down somewhere in California.
Your point is very well taken, this probably was really on the ragged edge of a Stage 3 Emergency and you are right to raise the question of did somebody fudge the SOP's. I suspect that the answer is tied to the inacuracy of the ISO forecasts and that somebody form outside the region stepped in to help out, big time.
smccorkle@caiso.com
Dear Ms. McCorkle;
I was hoping that you could help me understand what happened on the afternoon of July 9th.
Specifically, by my calculations from your Ca ISO website for the 3 PM hour had total generation exceeding load by only 694 MW or 1.6% of total generation.
Why was only a Stage 1 Emergency declared? Should not a Stage 2 or Stage 3 Emergency been declared under ISO SOP?s?
I thought that the ISO definition for a Stage 3 Emergency is the lower of 1.5% of generation or a single contingency which ever is less. During the 3PM hour, 1.5% was only 652 MW, which is less than a number of large nuclear plant could have lost in the event of a scram or turbine trip. At 1.6% of generation the ISO was on the ragged edge of Stage 3 if the largest single contingency is not considered.
Therefore, in your explanation of why wasn?t a Stage 3 emergency declared, could you tell me what was considered the Stage 3 criteria and why. Also could you explain why a Stage 2 Emergency was not declared. Finally, could you explain how the ISO went form a Maintenance Warning to and Emergency without any Alerts being issues.
As a concerned Power Industry professional engineer and former Power Manager, I would like to better understand the California ISO and how it operates.
Sincerely,
Any way to see that and who it is on the OASIS website?
It is now clear to me that socal_parrot's excellent graph represents 100% of available Resources or 97% of Available Generation (what I thought was meant by "Resources," namely what we make plus what we buy). That is certainly not as close as it seemed, but is clearly not an adequate margin for "business as usual."
If the margin below Capacity was but 1.6%, I don't think it shows that on the graph because it would show that the Reserve limit had been exceeded. If that is the case, then the situation I errantly surmised had in fact occurred and the question I raised (and you clarified) indeed applies:
Why only a Stage 1 Emergency?
Why only a Stage 1 Alert?
Thank you for your thoughtful post. There is investigatin' too due.
LOL!
I'll still bet it was Bonneville or one of the other large PNW utilities that bailed out Cal ISO by agreeing to sell a large block of power during the 4 PM hour.
I could also call some power dispatchers I know to find out, but am looking forward to hearing what you learn.
You got it, Gramps! It's hot here, too, so there's no problem turning down the air temp.
Since I want to do my part to get rid of Davis, I'll even turn on (and jump in) the swim-spa...
just don't make me heat it. ;o)
OK, thank you for the Cal Iso Oasis site, and it is not a pre registration-only site, so yes you can explore it. As to what happened between the 2 pm and 4 pm to save the ISO, it appears from my browsing that System Generation increased about 300 to 450 MW and that imports increase by a couple hundred MW. Combined this saved the system.
Also at the same time system exports increased a couple hundred MW's. (must have been those evil price gougers.) The two "15" paths seem to have been a big part of the equation for imports and the LC and PNW3 paths seemed to be part of the import solutions.
A quick glance appears to be that the ISO got by with little bits here and there. So I guess, it wasn't BPA riding in on a big white horse.
When I get a response from my request to the CA ISO communications director, I will post it on FreeRepublic and bump both of you.
I learned a few things today!
I wanted to communicate with the person who she would ask to answer my questions, first not to try to give me too much BS and secondly, how much rope did they want to hang themselves with.
Do you think I didn't sound sincerely? (grin?)
Something really doesn't smell quite right.
I hope that the morning papers have some good reporters who really probe what is going on. (yeah right!)
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