Fireman's Rant Addendum

I've had some more thoughts cross my mind.

This is a follow-up to the original Fireman's Rant on Drivers. If you haven't read that yet, do so and then come back.

QUIT WITH THE CUTE FAKE ROAD SIGNS. Yeah, you've seen them. On someone's garage or at the end of their driveway. Cute, you named your driveway after your clan, and now we all get to know that your little bit of pavement is "Johnson Drive". But let's reconsider, especially in light suburban or rural areas.

Yes, one day you are pulling out of your driveway, and someone who failed to HANG UP AND DRIVE whacks you into the ditch. You are bleeding and unconscious, and the other guy's car is on top of yours and starting to burn. A passing motorist stumbles into the scene, pulls out the handy cell phone and calls 911. County 911, what are you reporting? "Hey, there's been this big wreck, a guy is trapped and there's a fire!" Where are you? (looks around....) "At the intersection of Johnson Drive and County Road 1234."

(Admit it. You KNOW there are plenty of people out there dumb enough to not know the difference between a 'real' sign and the cute one.)

Here one of two things happens:

(1) Sir, there is no 'Johnson Drive' in the County. Can you get a street address on County Road 1234? Oh, by the way, are your mailbox numbers large and legible, on the front and both sides? No? Sucks to be you. Passerby walks up the road looking for someone else's number while you get crispy and/or bleed out.

(2) We'll send help right away. Oh yeah, seven miles up the way there actually IS a real "Johnson Drive" that intersects County Road 1234. Fire and rescue, probably from more distant fire stations, responds to the wrong location, while you get crispy and/or bleed out.

Keep the cute fake road signs out of sight from the road. Thanks.

HEY BRAKE TAPPER, WANNA GET DEAD? I was already going to add this little bit when a delightfully ironic story appeared in the Ventura County Star. So you don't like being tailgated, eh? Sorry, no defense to the bonehead following you, but your smart options are (a) live with it, and (b) let them pass you. And yes, of course, there is a stupid option (c) tap your brakes to 'send them a message'. Yeah, brilliant, the message reads: I am a freaking idiot and am willing to die, maim or kill others, or at least screw up all traffic in order to prove my point.

If all goes well, your brake tap dance slows traffic down for everyone as the braking slinky works its way back up the lane. Are you so important that tailgaters will not be tolerated to the tune of causing traffic delays, unnecessary lane changes, and the increased risk of accidents brought by lane changes and speed differentials?

And what if the bonehead tailgater is doing their lipstick, changing the radio, or texting? Instead of making room behind you, you have just caused an accident that you may or may not survive. Someone farther back may freak out and swerve over the median, wiping out a minivan of innocent children and their Mom. At the very least you've got a damaged vehicle, raised insurance rates, you're late for whatever it was you were going to, and you have caused my brethren, medics and law enforcement friends to all drop what they were doing and come clean up your preventable mess.

Was it worth it?

Ask this brake tapper.

Oh wait, never mind, he's dead. Must have been pretty damn important. Enough so, in fact, that fire crews already on their way to another ostensibly legitimate emergency stumbled into this and had to stop and assist. Not only did he get dead, he also screwed up traffic for miles, scratched his bike up really bad (bummer, dude), risked others' lives, etc... and he prevented help from getting to another emergency. What a hero.

Darwin Awards were invented for guys like this. Are you a candidate, too? Just get out of the way and live another day.

UPDATE 8/30/09: A 2nd addendum has been added HERE.

Tutorial 2 - AC Supply and Demand

Welcome back to another boring ramble. You seem to enjoy this punishment a little too much.

When we last left off, I mentioned how you cannot store AC power. There is no such thing as a battery for AC power, since the basis of the chemical process used to push DC electrons from your handheld gadget and automotive batteries in one direction only is wholly incapable of producing the precise 60Hz, constantly-reversing flow cycle utilized by the North American AC power grid.

Therefore, the power used by AC systems is generated at the same moment that it is consumed.

If you tried to hook up a single power plant to a city with no external connections today, it would be very difficult to control the system's stability and very hard on the power plant trying to do it. When AC systems first came into being a century or so ago, a precise frequency of 60Hz on the nose was not as important to maintain as it is today. For sure, a higher or lower frequency might result in a typical turbine (spinning at 3600 RPM) having funny vibrations and tripping to prevent damage, but relatively wide frequency swings could be tolerated because there really wasn't any sensitive electrical equipment in use by consumers 100 years ago that would burn up if exposed to, say, 59.43Hz or 60.78Hz. By comparison, at today's standards, anything outside of 59.90-60.10 is extremely unusual and would get our attention in a big hurry. 59.95 or lower, in fact, is usually a good indication of a noteworthy system disturbance.

As an amusing aside: Analog clocks on the North American grid, on 120 volt AC plug-in power supplies, are engineered to count one second for every 60 cycles of AC. If the frequency were to theoretically, say, drop to 59.00Hz for one hour, the clock would only advance 59 minutes during that hour. So, even minor fluctuations in frequency, over time, can throw these old clocks off. Accumulated frequency deviations are recorded as Time Error, and the operators of power companies are from time to time ordered to control to a slightly different frequency (59.98Hz or 60.02Hz as needed) in order to keep this accumulated deviation minimized. Heaven forbid an old clock lose two hundredths of a second over the course of a few days.

And yeah, if you plug in a clock built for the European-style 50Hz system into the North American grid, it will spin fast to the tune of 72 minutes for every hour of actual time.

Back to topic.

If you have a perfect match of mechanical-force-moving-a-generator to instantaneous-electrical-demand, the frequency will be 60Hz and all is well. As soon as something gets turned on or off (light switch, blender, table saw, whatever), the balance is disturbed and frequency will change. If there is too much mechanical input compared to demand, the frequency will rise until the balance is restored. This is accomplished by, among many other options, perhaps backing off the water fed to a hydro turbine, or by slightly manipulating the valves at a thermal (coal/gas/oil) power station to reduce the amount of steam reaching the turbine. Likewise, adding demand will reduce frequency until more supply is provided. Once balance is restored, frequency returns to 60Hz. If you get roughly an equal amount of low and high imbalances, the accumulated deviation tends to cancel itself out most of the time.

Now, as I said at the beginning of this post, if you had one power station managing an isolated city, it would be very hard for this power plant to keep up. Imagine at 10:20PM when a huge number of people turn off the 10:00 news and the lights, and hit the sack. The plant would probably not be able to back down fast enough to match the fast-dropping demand. Conversely, at 6:25AM when furnaces, coffee pots, water heaters, and lights all get rapidly turned on, it would be very very difficult for one power plant to keep up and prevent a huge frequency decay and system collapse. 100 years ago, these huge demand swings did not exist at this scale, so single-plant systems that wouldn't survive today were not so stressed out then.

Back in the 30's and 40's, and going forward, power companies began to tie their systems together to increase stability and reliability. By having a power line between you and a neighbor, you could schedule one of your power plants for an outage to repair or upgrade something, without having to black out some or all of your system, because you could fill in the shortfall by buying power from your neighbor, and vice-versa. In addition, if you have huge demand swings on the intertied systems, there are more total power plants exposed to the swings and able to respond. As the number of customers in a single intertied system increases, the individual impacts of things being turned on and off, combined with the averaging effect of having such a huge number of users on the same system, decreases the impact of individual demand changes in proportion to the whole, making load fluctuations much smoother. This in turn reduces wear and tear on power plants trying to chase demand and maintain 60Hz.

An analogy of the above. If you have shopping basket and keep randomly adding or removing oranges, the weight will change noticeably every time something goes in or out. Your arm will get tired of the changes. If you instead have a dump truck and have twenty people randomly adding or removing oranges, even if you do it kind of quickly, the dump truck really doesn't notice. Isolated AC power systems are shopping baskets. AC grid interconnections are fleets of river barges (bigger than dump trucks!) with crowds and crowds of people rapidly adding and removing oranges, and despite the chaos there is never enough sudden coordinated increase or decrease in volume to do much more than make even a slight ripple in the water.

That is probably the lamest analogy I have come up with for a while, but it will have to do.

Since frequency is sychronized on AC equipment tied together, the frequency is for all practical purposes exactly the same on any given point in an interconnection. There are two major interconnections in North America (east and west). Thus the frequency in Maine is exactly the same as that in Louisiana, and the frequency in British Columbia is the same as that in New Mexico... barring system disturbances and 'islanding', of course. If something seriously goes kaboom in Florida and whacks the frequency, dispatchers in Saskatchewan see it within four seconds on their frequency charts, and very likely look at each other and say 'I wonder who just got whacked, eh?'

I can't go on. Half of you are asleep already anyway.

What we learned: (1) AC power is generated almost precisely at the moment it is consumed by controlling output based on demand and frequency. (2) Large AC interconnections made up of bunches of power companies - their generators and loads all tied together - tends to blunt the impact of load changes, which minimizes imbalances in load and demand. (3) There are two huge interconnections in North America. The East is gargantuan, while the West is merely huge (Texas and Quebec are their own AC grids, weakly tied to the big boys with special high voltage DC power lines - more on that some other time). (4) Power companies actually spend time trying to make sure your analog clocks stay precise even though you can usually get the exact time from your cell phone or the Internet in less time than it takes to check or set your AC wall clock, and this of course assumes that you have ever attempted to set your AC wall clock to the precise exact second in the first place.

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Rewards and Insults

A while back I got singled out in the company-wide newsletter, sent to thousands of employees across many states. I was the lead article in an issue that only had two articles. Thankfully, it was for a good reason.

Here's how it went.

At work at the power company:

There was a wildland fire that was threatening a major transmission power line, which had to be shut down to protect the safety of the fire crews entering the area. It was likely to trip when the smoke and debris got into it anyway. Being a combination power guy and fire guy in my two lives makes me very sympathetic to the needs of the fire crews under and around my wires.

This time, however, there was a major industrial user on the line which must perform evacuation procedures when they lose power. So, I first called the big customer's control facility and warned them, and then dumped the line. I called them back fairly often to keep them appraised of the situation as it progressed, and kept in touch with the fire dispatchers as well.

Some sort of manager person at the big customer apparently liked my way of handling this incident enough that he wrote a nice note to my boss. Cool.

That night at work at the fire department:

Had a nondescript garage fire. I arrived in the 4th-due piece, which was never used on the call, just parked out of the way. I was late enough that I missed the initial attack entirely. I ended up shadowing one of our new guys as he played Water Supply Officer for the first time, answering his questions and prompting him as needed. He did fine. I really didn't do jack.

One of my coworkers just happened to live next door to this call, and found out I was there. The next day, she wrote a nice note to my boss. Cool.

My boss forwarded both of them to his boss. Ummm. It spiraled out of control from there, and an executive summary of a day in the life of the Grumpy Dispatcher ended up in the company newsletter a few days later.

You know, I really didn't mind, but let's be real here. Doing notifications and dumping power lines is just a small part of my job. It is not extraordinary or difficult. Driving a tanker to a fire and mentoring a new guy while not getting dirty is easy as well. I have had far, far scarier days at the power company keeping people from getting killed, and for sure have had far hairer fire and rescue calls. The only thing this time is that two unrelated nothing events somehow resulted in nice emails to my boss referring to the same day. That makes me a hero? Yeah, the only person laughing louder than you is me.

But the newsletter poke was OK.

I was reminded, however, of two times where the poke was delivered differently. I have to live up to my Grumpy nature and complain.

First case: One of my old Senior Dispatchers had a truly hairy incident where a couple of line guys narrowly escaped death only by his razor-sharp situational awareness and fast reaction. I wonder if I ever have a chance to be half as good as Rich. Anyway, the next day, the boss called him into the office. Rich is standing in front of the desk, kind of disinterested, the boss doesn't even stand up. Boss says some nice words about how Rich saved the day, reaches into a desk drawer and pulls out a fanny pack with the company logo silkscreened on and says something along the lines of how he just wanted to give him something to say thank you. You gotta know Rich, and apologies to any who may be offended, I am only the reporter here.... Rich takes the fanny pack, turns it over a couple of times, tosses it back on the desk and walks out saying "Why don't you just keep your fag bag, I've got to get back to work."

We don't need nor want a reward for what we do. We know what our job is and the consequences of failure. We are not motivated by trinkets or trade show handouts.

Second case: I was frustrated by the lack of usefulness of some of our software displays and was getting nowhere with requests to improve them. So, while on shift and still fulfilling my regular duties, I taught myself how to use the software to make my own displays. I learned where things could be found in the huge database, built some really excellent interfaces, refined their look and feel, etc. Now everyone uses my displays on all the shifts, and I have to maintain them when there are changes - while still doing my regular job - because no one else really knows how they are built or maintained. It's cool, actually, I kind of enjoy playing with this stuff.

The reward from management when it became clear what I had pulled off after hundreds of hours of work on this stuff: A $25 gift certificate to Target.

You know, just keep it. I'm just doing my job, and let's be honest... I am getting paid well enough that a gift certificate is just a fart in the wind, anyway.

However, when I rescue a falling baby while on crutches in the snow or otherwise save the world, I'll probably go ahead and take your gift certificate and buy myself a new DVD or two for the collection, because I do like movies.

Tutorial 1 - DC vs. AC

I got only one reply on the post asking if a tutorial series would be helpful. The one response was in the affirmative. So I guess it is unanimous, 100% of the responses were in favor of the tutorial stuff. Thanks for the vote.

I see the rest of you, you're generating bits of data on the traffic report. Little bits. But we're new here... and as I recall writing not too long ago, this blog is about me and my therapy, anyway, and not about what you want. So I'll continue the therapy and you can decide if you want to try to keep watching or not. I won't blame you if you turn away, unable to continue to observe the train wreck here.

Here's where I'll start the tutorial series. But I promise to try to amuse you with other topics as we go along.... don't plan on a straight uninterrupted series of boring tutorials.

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

Power grid interconnections are operated as alternating current (AC) systems. Most folks out there are familiar with direct current (DC) systems, with the traditional red positive and black negative lead wires, such as found on anything that uses a battery.

I'll push a moment on DC and batteries, because people are more familiar with them. I'll then use that foundation to explain how AC is different.

People often think positive equals ( + ) and that power comes out of the battery on its 'top', and that negative equals ( - ) and that the return path goes into the battery on its 'bottom'. Truth be told, the symbols refer to the flow of electrons relative to the battery itself. They come out (are 'subtracted', if you will) from the negative terminal, go out through the black wire, go do their thing running the whatever, and then return via the red wire to the battery (are 'added') through the positive terminal.

I suspect that I just turned the battery-using world of perhaps 85% of my readers upside down. Yes, some of you are applying what you just learned to automotive electronics if you've ever had to deal with that. And yes, the entire frame of the car is energized via the "positive" flow sourced from the negative terminal which subtracts flow from the battery, looking for a path back to the battery via wires to the positive terminal. That huge cable running from the starter to the battery? Yeah, that's the return path. Really. The so-called grounding strap off the negative terminal should be equally large, as it has to support the battery's outflow to start the car.

OK, so you all have the concept of single-directional flow down, right? Direct current. One way. From here to there.

Now, alternating current is a different game entirely. In an AC system, the current flows out and reverses direction along the same wire, rapidly. The neutral (ground) wire provides a balancing or pass-through point, if you will, so the electrons don't pile up and get "squished" at the remote end. It's actually quite a bit more complicated and technical than that, but we don't need to get into it for purposes of this blog. Suffice to say, AC systems do not have a 'positive' and 'negative' wire, rather they have a 'hot' wire (black) and a 'neutral' wire (white). On power poles, the hot wire(s) are at the top of the pole, and the neutral wires are lower down, at the base of the transformer cans mounted to the pole. Stuff below that is cable TV, phone, etc. The power comes and goes via the hot wire, whereas the neutral wire is tied to an electrical ground, literally (if installed correctly) via a 6' metal rod driven into the dirt or some other equivalent grounding installation at your home, and via a metal grid "grounding mat" under the gravel at electrical facilities such as substations.

Two important notes about AC:

1 - There is as yet no efficient way to store energy that can serve as a source for an AC system. Batteries use a chemical-based process to push electrons out of the battery in one direction. There is no chemical process that can push and pull electrons back and forth in the format of AC current. Therefore, all energy generated to serve the AC power system is generated at the same moment that it is consumed.

2 - The rate of the AC power current send-and-receive cycles, in North America, is 60 times per second, referred to as 60Hz or a 60 cycle system. That means every second, electrons arrive to do their thing, and are then returned, 60 times per second, and this super-fast back and forth action is what produces the quiet hum you hear from various electrical components, and the loud hum from electrical substations. I referred to the 60Hz rate in Compliance Follies. The hum you hear from a substation would rise or fall in pitch if the rate ever changed much, but in reality the rate will never change enough for anyone to audibly detect a difference (unless it goes to 0Hz, in which case it gets very quiet and our slow workday becomes busy). Much of Europe runs at 50Hz, which is why some sensitive electronics will not work in both places. In early electric systems, 25Hz was common, and this rate was slow enough that the unaided human eye could easily detect the flicker in light bulbs as they received power 25 times per second.

What we learned: (1) Batteries flow the other way, and Mom never told us that. We are traumatized by the revelation. (2) You cannot store AC power. (3) AC is weird.

More later.

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Learn the Grid. Attract the Ladies.

This blog is sooooo new, yet people are already reading it... I can see the stats and am surprised. As MotorCop so eloquently stated, and I am merely paraphrasing here, this freaks me right the frack out. But I also have to acknowledge to myself... hey dummy, you put it on the Internet, what exactly were you expecting?

I only put up one power company post so far, and although I tried to keep it very elementary, the comments tell me that it was still jargonized greek. Thus not very entertaining. Like any line of work, you get immersed so far into it that sometimes it is hard to explain to someone with little or no exposure. Sorry about that.

I will start a series of posts to explain the power grid and power dispatching from a very basic level, and with any luck get all three of you regular readers qualified to pass the NERC certification exam and be dispatchers as soon as possible. Honestly, we could use the help, and it pays pretty well.

Seriously, is anyone interested enough in how the grid is operated to make it worthwhile for me to make a dryly cynical tutorial series? By the end, you'll know enough to impress the chicks at parties with your extensive power grid knowledge, especially when they want to talk about the blackout that just happened (and there will be one eventually, just wait). Unless of course, one of us power dispatchers is also there and chooses to out you as an imposter. And even then, it only works on the chicks who dig grumpy blue collar types who think like self-righteous engineers.

On the other hand, if you're female, I am not sure how the men will react to your grid knowledge. Unless it's a power dispatcher. We love to talk shop!

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