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Wednesday, September 30, 2009

Deer Fail or Win, We're Not Sure

This Fail picture posted in honor of Officer Krupke's recent post about a deer encounter.

Next time, Officer K, do it this way and the questions won't be about if there was a deer involved or not.

This pic also includes a secondary but unlabeled FAIL: Nice parking spot... pay no mind to that there hydrant.


My First Line Trip

A long time ago, in a control room far, far away . . . . .
 
I was a wet-behind-the-ears dispatcher. Just got bumped up from being the 'numbers' and generation balancing guy, and moved to the desk where real stuff happens. Circuit breakers that I can control.

Three Mouse Clicks from Disaster!

There is nothing you can screw up on the numbers desk that cannot be fixed by an accountant with or without a checkbook.

But now, a mistake will darken cities or blow stuff up, or worse, injure or kill someone.

Yes sir, I made the Big Time. And I was Ready!

Here we go! Update the Log. Grumpy Dispatcher is on the Desk!

(boring hours of pretty much nothing ensue..........................)

Beeeeeeeeeeeeep! A 115kV Line trip! Action!

I jumped out of my chair almost as fast as I did the first hundred or so times my old-school red Minitor I "brick" went off when I was a jumpy new firefighter probie.

Whoops, wait, no turnouts to don here. I'll just sit back down and act like I meant to do that. Yeah.

Supervisor comes over. I'm really working under his eye, not on my own. But I've got my own desk. Yeah, I'm the man.

He suggests I try to close in and test the line.

Smoothly, I pull up the control window for one of the breakers. Act like you've done this before, make it look good.

Yes, I am The Man, I control big circuit breakers miles away!

"Select", "Close", "Confirm". Three Mouse Clicks.

Nothing happens.

Try it again, he says. Three clicks. Nothing.

Try the other end, he says, maybe the relays won't let you pick that line up dead from that end.

Click, click, click. This time it shows closed for a second or two, then opens again. Locked out.

A real outage! Drama!

I get to pull out the callout list and talk to the crews, and direct them in to patrol the line and save the day.

My shift ends before the crew arrives at the site. I pass along the info to my relief so he can finish the mop-up. My work here is done.

----------------

Back in that night. Ready to watch over the world for another 12 hours.

Guess what, rookie? Yeah, that line you tested three times? Yeah, those first two tests the breakers popped back open so fast they never showed closed on the console. Well, the conductor was laying on the guy wire, and you banged into the ground three times and started a nice fire. 25 acres last I heard. Aren't you a fireman? Way to go, rookie!

Um.

Oops.

The intervening years since that new (and not yet Grumpy) dispatcher hit the desk have made this incident increasingly amusing over time....


Tuesday, September 29, 2009

Pole Bracing Fail

Yep, just what we needed, that'll hold 'er until tomorrow!




A Few Pointers From This Weekend

If you decide to get drunk, please don't drive.

See, if you'd stopped right there, a lot of issues would have been resolved pre-emptively. But, alas, it was not to be.

If you wreck your car driving drunk at 0430 on a Saturday morning and you decide to try to drive away, make sure your vehicle will still operate with enough functionality to go somewhere.

If you fail to determine that one rear wheel has been completely ripped from your car and the other rear tire is jammed into a fender, do not use what little capability your vehicle has to go farther away from the road.

If you use what little capability your vehicle has remaining to make a run for it, don't get it hung up on the only planter within 100'.

If you get your vehicle hung up on a planter and decide to run for it, don't leave your wallet on the front seat.

Or your cell phone.

If you leave your wallet, don't leave your ID, which matches the registration on the car.

Or all that money in it. Wow, dude.

If you run off and leave your wallet behind, ostensibly because you don't want to get caught as the driver, don't walk in plain sight on the main road where ambulances, fire trucks and police cars will come from.

If you are trying to get away on the main road and get spotted in the headlight beams, don't call attention to yourself by ducking conspicuously out of the way after you've been shined.

If you got shined and then ducked without success, and have now been detained by the police department, have a better story than that you were out looking for your lost dog. At 0430 in the dark. On a quiet country road MILES from where you live.

If you claim you were looking for your dog, know its name and be ready to describe it without having to give it some thought.

And be ready to come up with a plausible local address instead of blurting out your real one miles away (that miraculously matches the address of the RO of a nearby and recently wrecked car) before adding that you moved to the area recently. Uh huh.

You have much to learn, and there is scant hope for your future (or ours if we have to carry tools like you through life).

In the meantime, your right to vote and share our air ought to be rescinded along with your right to drive.


Friday, September 25, 2009

Let Me Press This Button Here

Let me introduce you to my Dad, the Smooth Substation Operator. He worked for a municipal electric utility for many years. I loved hanging out with him at work as a teenager, riding out with him in the van as he did his rounds at various stations, taking readings, tagging devices, doing some switching every once in a while. Of course, we also got to jump car wrecks and house fires any time power lines might be involved.

Part of the tour of a shift always involved some time at the Control Center, with old-school grizzly dispatchers so grumpy that I'm Mary Poppins. I learned how to behave around them, and knew I found success when they started to let me have a donut once in a while. I thought, dang, these guys have a cool job. I'd like to try that one day. I wanted to be a firefighter as my first aspiration, but power dispatching also looked like awesome stuff for a control freak like me. Lucky me, I get to do both!

Despite his employer constantly leaning on him to give up his senior spot as a station operator and become a dispatcher, Dad was never dumb enough to take them up on it. Yeah, here's your raise, now you have to sit in the control center and deal with bosses wearing ties all day. No more time outside, on your own, watching baseball on your portable black and white TV at lonely remote substations. Smart man, my Dad.

ANYway.... this is one of my favorite stories he's shared with me. Wish I had been there. I don't remember the specifics, but the essence is accurate.

So Dad is working a stint on a project at the control center instead of out in the field. There is a routine feeder outage that a dispatcher is handling, and Dad is working near the consoles. Dad's company was much, much smaller than the behemoth I work for, so the dispatchers did in fact have to handle some of the overflow calls from customers. The phones keep ringing, and Dad decides to take a call to help the guys out.

Smooth Substation Operator: City Light, how can I help you?

Little Old Lady: Yes, I live at 486 Rose Lane. My lights have been out for a while now, do you know when they will come back?

Dad has a remarkable ability to listen to about four things at once, so in the din he overhears the dispatcher giving orders to a station operator. The feeder has been repaired and they are about to re-energize. He realizes that Little Old Lady is on the feeder.

SSO: Your lights are out? Well, I think I can probably fix that for you, ma'am.LOL: Really? Oh, thank you!Dispatcher in Background: 309, close power circuit breaker 14 at Garden Court Sub.Truck 309: Copy, close power circuit breaker 14 at Garden Court Sub.DIB: That is correct.
SSO: Aha, there's the red button I was looking for, let me press this for you!

Within the next few seconds, the Truck 309 crew closed the breaker and picked up the feeder.

LOL: (sweetly) Oh, thank you, so much, they're on now! Thank you so very much! That did the trick!SSO: Of course, ma'am, thanks for calling to let us know. Call back anytime!

I can only imagine the conversation that ensued the next time Little Old Lady's lights went out.

LOL: Well, last time I called, you guys just pressed that red button on the desk. Why can't you do that again? Honestly! I want to talk to the man who helped me last time!

Brilliant!


Wednesday, September 23, 2009

Clue Meter is Reading Zero

We have a sort-of entry-level position here in the control facility for a 24/7 security monitoring desk. Their job is to monitor all of our substation and communications facilities for security and data link problems.

If a gate or building is opened after hours without explanation and they cannot find out who is there, they call the PD local to the facility. If an environmental sensor shows that the cooling or heating to a building has failed, they call out a repair crew to investigate. If a datalink fails, they call a comm tech out to fix it. That kind of stuff. They don't run the grid, but they do most of the irritating fluffy non-critical stuff so that we dispatchers are free to focus on the seriously critical stuff, like not killing field crews or blowing up multi-million $$$ transformers and the like.

You don't need any special experience to come into that security job, but it is nice if you are intelligent, and inclined to proficiency at technically-oriented stuff. For the most part, these guys are. If they impress, they may be selected for training to pass the NERC exam and get certified, and might get a crack at being a dispatcher in the future.

But I digress.

The security guy on duty comes over to my console.

Security Guy: Hey, just wanted to let you know, I've got a low fuel alarm on the diesel generator at the Holly Peak microwave site.

An aside: To facilitate secure communications with remote substation outposts without telecom access, microwave signals are utilized. Frequently, stand-alone microwave towers are installed to talk to several nearby outlying substations and link the data with us here at the mother ship. These microwave sites are moderately critical, because the loss of one can result in loss of view and control to multiple substations. As such, they almost always have on-site backup diesel generators.

Grumpy Dispatcher: Is the generator running? Is the loss of AC alarm in? (loss of AC means its local electric service has gone dead)

SG: No, nothing else but the low fuel alarm. The alarm has been in for a while, I was waiting for it to clear.

An aside: Some fluffy alarms come in and out for a variety of reasons, say due to fluctuating temperatures or atmospheric interference with microwave signals. No reason to call anyone out for some of these until they are sustained. There are no plausible reasons for a 'false' or 'temporary' low fuel alarm, though.

GD: (looks at the clock, it is 0420) How long? When did it come in?

SG: I think at about 0130.

Three hours, he waits, to tell me about this?? Teeth clenching ensues.

An extended aside: So what brings in a low fuel alarm? Just two possibilities exist: (1) The fuel is low, or (2) The sensor is faulty. The probability of a sensor randomly dying at 0130 is astronomically remote. These are just fuel gauges, c'mon. They don't have an established history of just up and dying. So let's go with the more likely cause: The fuel is low.

What causes the fuel to be low? Just three possibilities exist: (1) The generator is running, consuming it. (2) It is leaking out, or (3) It is being removed by some other means. Hello... these things hold 50-100 gallons, and as a rule are in the middle of nowhere. Checked fuel prices lately?  Did any of you really need me to walk you through that process if you'd been given a few minutes to consider the possibilities on your own?

Well, option (1) is out. Generator is not running, as there is no alarm indicating its run status has changed, and the site has also not lost its AC feed.  That leaves.....

Option (2), a leak.  It's a haz mat incident and a system reliability degradation, requiring immediate callout.

Option (3), removal.  It's a crime in progress and a system reliability degradation, requiring immediate callout.

Like I said, teeth clenching.

By now it is far too late, so no reason to get excited. Whoever was there stealing the fuel is now long, long gone.

I ran through the same line of deductive reasoning with the guy, slowly and step by step, to help him through the logical process.

The light eventually clicked on and he finally looked alarmed.

SG: I guess I should call someone out right away, then?

GD: Yeah. Three hours ago.


Haz Mat Canary Fail

I am not convinced that this isn't a photoshop job, but it is still a crackup. This Fail picture brought out of Grumpy's files in honor of Firecap5's recent blog entry.




Tuesday, September 22, 2009

Tutorial 5: Introduction to Power Lines


It's been getting boring talking about math and meters, and about the ethereal nature of megawatts, which you cannot hold, observe, or really grasp in any physical sense. The wonders of Reserve Sharing Groups only turn the crank for dispatcher geeks, accountants and penalty-fearing compliance people. Let's move on to something tangible and different, to freshen the air.

Power lines. They're everywhere, above and blow the ground, so much a part of your life that you usually don't notice them. They come in all shapes and sizes, and to the untrained eye they are not always differentiated from other cables and wires strung around for various purposes.

To make sense of the different sizes and types of power lines, though, we have to delve ever so slightly into the technical aspects of power transformers.

And to get into power transformers, we have to poke at the terms 'voltage', 'amperes' (amps), 'watts' and 'ohms'. Dang, here we go with the boring/technical again. I'll try to be brief.

Let's convert those four things into the fire service world, applying what we know about the physics of moving water.

Volts = Water pressure
Amps = GPM flow rate
Watts = Gallons of water moved
Ohms = Friction loss

To move water efficiently and get the desired volume of water on the fire, you like good pressure and low friction loss in order to achieve a good flow rate. The same is true for electricity. The best efficiency to provide the desired amps and deliver the watts comes at high voltages with low ohms.

OK, we're past that boring definition part. That was quick, right?

Power generators typically produce electricity at anywhere from 6,000 to 14,000 volts depending on each station. Converted to industry terms, that's 6-14kV, and is about the same voltage used for residential distribution circuits running through neighborhoods. Voltages that low are not efficient at long distances greater than several miles, any more than trying to pump 1,000' of 1.75" attack line. You need to step up the pressure and put that water into some LDH (large-diameter hose), and bring it back down again near where it is to be used.

Bring in the transformer.

Without getting into its technical aspects right now, suffice to say that a transformer is what increases or decreases the voltage. Unlike the adjustable fire pump, they have a fixed ratio of conversion. For example, a 115/14kV transformer can only convert at that ratio. If its incoming high-side voltage, nominally 115kV, is reduced by 10% (to ~103kV), the outgoing voltage which would normally be 14kV will also be reduced by 10% (to ~12.5kV).

The concept of pressure regarding voltage also has to do with how far the electricity can potentially flash or arc to ground. Thus, the higher the voltage, the more clearance around the wires is provided and the longer the strings of insulators. Don't let the presence of only one or two insulator bells on a little distribution circuit make you think it is safe and small, though, as even the low end 6kV circuits can blow your arm off.

So, generators create power at relatively low voltages. The power stations have transformers that step up the voltage to efficient levels for long distance transmission, say anywhere from 115kV to 500kV, in some cases higher. High voltage = LDH. The network of high voltage transmission lines of various voltages generally comprises the "grid".

Attached to the grid are transmission substations. This is where the high transmission voltages are stepped down to levels suitable for delivering power to the distribution substations that actually serve the customers, bringing the big voltages through more transformers down to perhaps 34-69kV (subtransmission). Then, attached to these subtransmission circuits are the distribution substations with yet more transformers that step it down again for localized service, back down to the 6-14kV (distribution) last seen at the power plant.

Finally, in those gray 'cans' attached to the power poles, or under green metal boxes on small concrete pads on neighborhood street corners, are still more transformers, which drop the distribution voltage down to something Firegeezer's coffee pot and all your other household stuff can handle, converting whatever is on the power line down to a reasonable 120 volts (which of course can still kill you).

What we learned: (1) Moving electricity isn't quite so mysterious once we apply the moving water analogy to it. (2) Transformers are magic, but not very flexible about how they do their magic. (3) Volts, Watts, Amps and Ohms used to be totally mysterious, but now makes total sense because the water physics analogy helps us make sense of them.

(Click this link to see all posts tagged "tutorial"



Monday, September 21, 2009

Is it Really That Difficult?

I know this brand of rant is nothing new to many of you, but it just really frosted my weasel when this happened to me. Seriously, what motivates some people to be such dunderheads?

Squad 51, Medic 98, and ..... I guess .... Mayberry Engine 13 (??)..... respond to ______

What the hell is that? You guess? I usually love fire dispatchers, but honestly, Mayberry FD in the next county over is on some of our run cards at the edge of the district because..... wait for it..... we want them to respond. Imagine that.

It's "nice" that they verbalize Mayberry on the dispatch, but I know from past experience that they don't actually go through with it and request them from neighboring Hazzard County.

So, I go grab the squad from Station 51, come online, and ask for 13's. You know... because we, like, want them to actually respond with us.

Squad 51 is responding. Please notify Hazzard County to have Mayberry respond. Like you should do without me having to ask.

10-4 Squad 51.

A minute or so goes by. I am first-due but have not yet arrived at the call.

Squad 51, Hazzard advises they don't think anyone is at the Mayberry station.

Expletives. Is this for real? They don't think anyone is home, so don't bother? Is this from the same flowchart they use when Mayberry has a call of their own? News flash, Mr/Ms Hazzard County dispatcher.... Mayberry is an all-volunteer, unstaffed house to begin with. Thus the house is empty almost all of the time. Not only that, but..... wait for it..... they have.... pagers! Dude! Go Technology!!

Squad 51 copies, please direct Hazzard County to dispatch Mayberry anyway. Really, this should never have gotten to step #2, and what are we on now, step #5 or so? This should be lock and load and Mayberry en route from the starting gun. Unbelievable.

I arrived. The medic arrived. A Mayberry unit did eventually show up, surprisingly late even with the drama. You see, Hazzard County dispatched them with just a house number 'across the county line', which apparently is a stand-in assumption for the major route between our districts. Except that's not where we were. Mayberry eventually found us anyway. It is not clear which dispatcher dropped the ball on the address, but that's just a bullet item on a long list of Shouldn't Happen.

We compared notes... there was a ten minute delay from the initial dispatch to when Mayberry got the dispatch - to the wrong location. Mayberry is able, willing, and.... available. If only the information could get to them unfiltered and without delay.

Can't... find... words... to... describe... the... madness...



Sunday, September 13, 2009

Epic Fail - Check that Warranty

Why it is sometimes good to travel in groups.





Don't Be Owned - The Fire Version

Last night I remembered a fire-based story I read online some time ago that was a perfect example of pushing responsibility where it belongs. I am not sure of the specifics so I am probably taking literary license here, but the core message is the same.

A crew member of an engine company had damaged one of his structural fire gloves on an earlier shift. Upon morning inspection the problem was noted. The Captain told his guy to chuck the gloves into the can, and they summarily traveled to whatever station where the department's personal protective equipment was stored.

Apparently, the battalion chief at this location in charge of this stuff was under the impression that the guys working on the job were out to destroy gear or steal from the agency. Heaven forbid they actually perform work and wear stuff out. He wanted proof that the gloves were damaged, but the bad gloves were not present. He refused to issue new gloves.

The Captain noted the portable radio on the BC's desk, waited several beats, and asked if he could use it. The BC, perplexed at this unexpected request, complied.

Dispatch from Engine 45.
Go ahead, Engine 45.
Engine 45 is out of service, due to a crewmember not having full PPE.


Oops. The whole world heard that.

You see, that department's SOP's, like pretty much everywhere, do not permit a firefighter to engage in fire combat without full gear, nor allowed crews to engage in tasks without a minimum crew size. The good Captain was merely following SOP.

So, what to do now? Well, E45 is out of service, and unless the BC makes a move to fix the problem (as he is the only PPE guy), these guys can just go to Delmonico's for an early lunch and then chill by the riverwalk and watch the ladies stroll by for the rest of the day.

The FF got his gloves. E45 went back in service over the air a few minutes later. The whole department, in minutes, figured out what had just transpired, and how to own the BC if he ever tried that trick again.

Don't be owned.


Saturday, September 12, 2009

The Grumpy Acronym Glossary

I promised I would get to this eventually. Here you go. More boring junk. This post will be updated as new terms are brought into play, and will be linked to from all new tutorials going forward.

ACE - Area Control Error
A numeric value, in megawatts, that a power company's Control Area is under or over-generating at any given moment.

AGC - Automatic Generator Control
A computer program that determines the best reliable and economic means to move all of the power plants, within a particular power company's area, up and down in order to keep energy production costs as low as possible, reduce wear and tear on the power plants, yet maintain adequate system stability. The AGC program is used to automatically control power plants in real time, but can be overridden easily in an emergency.

MSSC - Most Severe Single Contingency
The single biggest, baddest, most horrible thing than can happen to a power system within a defined area, at least within the constraints of the imaginations of that system's dispatchers and planning engineers. If you have four adjacent power systems tied together to form one grid, each of those four will have their own MSSC, but the worst of all four is also that grid's collective MSSC.

MW - Megawatt
A unit of energy, equal to 1,000 kilowatts. There is a slight differentiation between an instantaneous MW flow rate and the amount of megawatt hours (MWh) delivered over a period of time. For example, if 100MW flows across a line for only 30 minutes, and then the line trips out of service, that line still successfully delivered 50MWh during those first 30 minutes (half of the 100MWh it would have delivered if it had stayed in service). For reference, a typical single family residential home may consume something in the neighborhood of one megawatt of energy over the course of a month.

NAI - Net Actual Interchange
A numeric value, in megawatts, that a power company's Control Area is receiving or delivering collectively from all of its neighbors at any given moment.

NSI - Net Scheduled Interchange
A numeric value, in megawatts, that a power company's Control Area is supposed to be receiving or delivering collectively from all of its neighbors at any given moment.

SF6 - Sulfur hexafluoride gas
An inert, relatively harmless gas used inside of high voltage circuit-interrupting equipment such as circuit breakers and circuit switchers to extinguish the electrical arc created when breaking contact between energized components. Very high voltage switching devices, if opened under load without SF6 capability, are likely to produce dangerous and potentially destructive electrical arcs which can destabilize the system, cause other equipment to trip offline, burn things up.... all right, enough, you get the idea.

Did I miss anything from the posts I have already dumped into your lap? Under or over-explain anything? Comments as always welcomed...


Sunday, September 6, 2009

Outrigger Interlock Fail



If you have any good Fire/EMS/Police FAIL pictures to share, feel free to pass them along! GrumpyDispatcher [at] gmail [dot] com.

Saturday, September 5, 2009

Tutorial 4: Basic ACE, and Reserve Sharing


I am a little slow today. The company buys the worst coffee, it should be labeled Acid Death Blend or something, clearly a product of the lowest-bidder process. I buy my own coffee and bring it in. For some silly reason I did not notice that what I picked up last time was decaf until I got to work with it. Still, I'd rather have good decaf than acid death just for the caffeine. So, my daily dose of pick-me-up has been missing a few days. This may explain the lag in posts. Maybe I should have put in to work Geezer's house this week... the coffee is always perfect there.

So what did we most recently learn? Power companies meter the flows on their power lines and keep track of energy transactions with their neighbors, so they know how much energy to produce in real time. They know what each power plant in their system costs to run. They have fancy gadgets that automatically run units as cheaply and efficiently as possible to keep costs down while maintaining system stability.

Today we'll elaborate slightly about the math, but I'll try to keep it light. Then we'll talk about how companies help each other recover from the loss of a big power generation station.

New acronym: ACE. Stands for Area Control Error. I promise a glossary is on the to-do list.

The first component of ACE is the difference between your scheduled energy transactions ('net scheduled interchange' - NSI) and the actual energy flows into and out of your system in real time ('net actual interchange' - NAI). We talked about this in the last tutorial. If you have agreed to various transactions with all four of the power systems that touch yours, and the net of all of those transactions put together is an import of 150 megawatts (MW), then your NSI (intended amount of flow) is 150 into your system. In power company terms, it would actually be shown as -150. A negative number is used to show that it is being imported into your system; it reflects a 'shortage' on your part, while a positive number is used to show an export, reflecting a 'surplus'.

So, I digress. We have the first piece of the puzzle. Your NSI is -150.

In real time, instantaneous measurements of all of the power lines attaching you to your neighbor power systems are collected. Added all together, let's pretend that the flows of all of them, some in and some out, come to a net sum of an import of 135MW (or, -135, remember negative numbers reflect a shortage as energy is flowing in to make up the difference).

There's the second piece. Your NAI is -135.

These difference between these two pieces, the NAI and NSI, make up the base component of a power system's ACE. The math is easy.

(NAI) - (NSI) = ACE
(-135) - (-150) = 15

Remember, a positive number represents a surplus. That makes sense here. Since you are supposed to be getting 150MW over your ties, but are only getting 135MW, it means you are generating too much electricity, which prevents your full 150 from coming in, and you need to back off a bit. The demand in your system will not be changed by you moving your units down, so after you back your generation resources off 15MW, the replacement power to serve that unchanged demand will start flowing in from your neighbors, raising your NAI to 150MW coming in.

Now that your NAI and NSI are both 150, your ACE is 0 (zero), which is where you always want to try to be. In reality, the ACE will constantly fluctuate above and below zero as your AGC widget tries to move your generation plants to keep up with changes in demand. Perfect zero is pretty much impossible, but you try to keep your average there.

There, that wasn't so bad, was it?

There's more to the ACE, which has to do with system frequency and how neighbor mismatches are resolved, but we'll get into it some other time after you've had time to digest this much. We'll move to something easier: Reserve Sharing.

In the Power Company universe, we are always supposed to operate in a configuration designed to withstand the most severe single contingency (MSSC, another reason to build that glossary). In other words, engineers and dispatchers dream up the worst single thing they can think might happen, and operate the system in a manner that it should survive the hit if that big bad horrible thing actually took place. Truly, we operate to hopefully survive a variety of big bad things of various types.

As far as generation MSSC events go, that means you figure out what your biggest power station is producing, and make sure you have room left to move all your other units up to cover it if it should trip. Theory being, if you lose your big dog, your other units can collectively make up the difference. Oh, and you need to be able to get there in fifteen minutes. Ideally sooner. Remember, not all units move that fast, so simply having that much remaining capacity is not enough. You need to have that capacity on units that can actually make it that fast or faster.

Let's apply this to the extreme small scale. Let's say you have two coal-fired steam power plants, each capable of 400MW. You could run one at full and keep the other one offline, but it is impossible to get a steamer from 0 to 400MW in fifteen minutes. Logically you might conclude that the answer is to run them both at 200MW. If one trips, the other one moves up to cover, right? Still, a big unit like that probably can't even move 200MW in fifteen minutes.

Let's move closer to real life and assume they are both rated to move 10MW/minute in an emergency, thus in fifteen minutes, either one could move 150MW if they had to. So now you're into your time-limited emergency capacity rating, that is, in an emergency if you lose one unit, the other can only help 150MW. That 150MW is therefore the biggest emergency you can recover from successfully. As a result, you are not permitted to run either of your 400MW units over 150MW each. This is because, if either one were higher than 150MW and then tripped, you would not be able to recover in time, according to industry standards. If you need more than 300MW to serve your customers (150MW from each plant), you're buying it from your neighbors. The remaining 500MW capacity from your resources is just wasted. You can't use it because you can't recover from losing any part of it.

That's not very efficient.

Let's add a neighbor. And we assume that the tie lines between you and the neighbor power system are not a limiting factor. Your neighbor also has two 400MW steamers, bringing the total on this mini-grid to four units. You and the neighbor agree to help each other out in an emergency. Now, if you lose one unit, you have three units left on this mini-grid that are each rated to move 150MW in fifteen minutes, for a total of 350MW of available 15-minute emergency replacement power. Now you can run them all at 350! Hooray!

Not so fast. Did you do ALL the math?

Four units rated 400MW, each running at 350MW. One trips. The other three respond. They were all at 350MW and each one has only 50MW of capacity to move up before they top out, for a total of 150MW of emergency energy. That leaves us 200MW short of recovery. Oops.

Where's the balance point?

I could wait and let you do the math, but I'll do it for you. If all units run at 300MW, each one has 100MW capacity in reserve. If you lose one unit and are down 300MW, each of the remaining three has 100MW to provide and you can recover.

This is an improvement, but we're still running these guys at just 75% of their rating.

In reality, almost every power company in North America participates in large Reserve Sharing groups. Very large groups, with hundreds and hundreds of power plants in the mix. The loss of one monster unit of 1,500MW is spread out amongst all of the members, each maybe being responsible for perhaps 5-10% of the event. Let's say you were a major participant and were responsible for assisting at 10% (150MW). If you are that big of a player, you probably have 75-100 power plants on your own system, so coughing up 150MW is nothing.

It is like a big neighborhood watch. You've got lots of help waiting out there when you need it, and individual participation impacts are so low, you can run your units up to 90-95% or more without fear of getting burned in a big emergency.

I've been doing this job for a long time, but I am still struck with how cool and smart Reserve Sharing Groups are. They are the Mutual Aid of the power industry, or more accurately, the Automatic Mutual Aid. Always nice to know that someone's got your back.

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Wednesday, September 2, 2009

Fire Attack Fail

I love the Fail Blog, and I even decided to send this pic to them, but I think it would be better appreciated here.

I've got quite a few more. I will put one up from time to time, here instead of there. Amusing pics are blog candy, giving people something to look at and chuckle over when they get tired of reading my drivel.