jesse
@ July 28, 2009


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6

Other than the worst, most befuddling Super Bowl ad in history, what is this?

When I first saw this ad, I was confused, and I am involved in the industry.  The reason I'm writing about it now, seven months later, is that I can actually answer some of the questions this ad posed while refusing to answer. And there is so much to explain that it is going to take a few days. So sit back and relax as we embark on Smart Grid Week here at ObscureCraft.

I can already feel you tingling with excitement.

What is the smart grid?

Plug something into your wall outlet, and it comes on. Magic, right? Sorta. But how did the electricity get there, and where did it come from? This question is at the heart of understanding the smart grid.

Let's compare electricity to another utility, water. Somewhere in your area there is a reservoir filled with water. When you turn on the tap, you are taking a little bit of water out. When it rains, the reservoir fills back up. Because there is a reservoir, it does not have to be raining the instant you want water.

In the electric grid, there is no reservoir. When you turn that TV on and ask for that electricity, somebody, somewhere, at that exact moment, has to make a little more electricity for you. What? Yes. Really. How does that work?

It works through the use of peak load generation equipment. There are types of generators that must be on all the time (like a nuclear power plant) and there are types of generators that you can turn on and off (like a gas turbine). Because there is a minimum amount of electricity that is always being used somewhere, those huge "base load" plants can stay on. Then, when its a hot day and we all start turning on the air conditioning, regulatory agencies that monitor use on the grid can call up the guy with the gas turbine and tell him to fire it up.

This system is riddled with inefficiency. There is a huge time lag between when you turn on the AC, and when the gas turbine finally comes online. The regulators monitor the health of the grid by reading its voltage. As more and more demand occurs, the voltage on the grid drops. Regulators respond to this drop by calling the gas turbine guy. So anytime they call the gas turbine guy, its an emergency. These emergencies happen all the time. Because its an emergency, peaking generation equipment is not held to the same emissions standards that base load equipment is. When you turn on your air conditioner in the afternoon, you are using the dirtiest electricity imaginable.

Furthermore, the laws of supply and demand dictate that, when demand goes up, prices do to. Real-time prices for electricity move during the course of the day - except residential consumers typically have a rate that is locked in during the month. Therefore, the cost of electricity you pay has already factored in that you will use a certain amount of this more expensive electricity.

The smart grid would use digital technology to report on energy supply and demand in real-time. Consumers, producers, and regulators could all act on this information immediately, instead of minutes, hours, or in some cases, days later. The consequences of this change are wide reaching, and will have impacts on renewable energy implementation, efficiency of existing generation assets, and energy costs. How, exactly?

Sorry, this is only part one. Tune in tomorrow for more.

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You claim:

When you turn on your air conditioner in the afternoon, you are using the dirtiest electricity imaginable.


This is incorrect. In the U.S., most peaking plants are natural gas fired turbines and a few are hydro. These are nowhere near as dirty as base load coal fired plants.

Oh ho ho ho but it is true. I come with numbers. Behold:

Peaker plants do not have the same emissions control requirements that base load plants do. They emit more nitrous oxides and VOCs, which contribute to zone (smog).

And while a gas turbine may be better than a coal plant, in Texas where we live, a natural gas fired turbine on its own emits more carbon dioxide than the combined base load plants, because of the amount of nuclear involved. In fact, its not even close.

http://ecalc.tamu.edu/EmissionsWeb/default.aspx

Play with that. You'll see in Harris County that the emissions per MWh (1000 kWh) is 991 lbs CO2. A gas turbine emits closer to 1200 lbs CO2 per MWh. So, while I had sort of a Texas-centric view when I made the statement, it is absolutely correct.

Jesse, I'm finding this entire series fascinating. I've got a few questions, since my experience with electric generation and distribution is limited to the shipboard type.

1. You mention that the regulators watch the voltage and when it starts to drop, they call up the peaking generators to start them up. Generators I work with have a voltage regulator that increases the exciter current as load increases. The system voltage remains steady the entire time. If you start seeing a voltage drop, you've already exceeding the capacity of the generator (brownout). Instead we monitor power and current (indications of real and reactive load, respectively) to know when to bring another generator online. Question is, is this a fundamental difference between how a large distribution system and my small system operates? Or is your referring to monitoring voltage a simplification?

2. Why would the peaking generators not be regulated to the same standards as base load generators? Are standards loosened based on them not being online as often? Is it based on the type of generators that are being used (nuke vs. gas turbine)? Or would that be based on locality?

I'll leave the last question for you next installment, since it sounds like that's where you're leading to anyway.

Gomer, thanks for the feedback. The fundamental difference between your small system and the large systems is the amount of information available. Regulators are not able to monitor the power and current on the entire system because they don't have the information to do so. That's what the smart grid will provide them with.

If they were able to do that the system would work much more efficiently. However, they can monitor the voltage and frequency on the lines, which indicates when the grid is approaching a brownout situation (brownout does not actually occur unless they run out of capacity, as they are able to bring it online quickly enough to avoid problems like this).

If you really want to dig into it, the regulatory body for the Texas grid system, ERCOT, publishes tons of information on their website. Here is their historical load information and forecasting data:

http://www.ercot.com/gridinfo/load/index

As for peaking generators, you are correct: standards are loosened based on them not being online as frequently. However, there are local rules that come into effect. For example, in Houston, which has been declared to be in severe non-compliance with the National Ambient Air Quality Standards defined by the EPA, you would not be allowed to build a peaking generator without environmental controls. Of course, that just means they build them somewhere else.

Interesting point, though I'm sure everyone would agree.

Man, you must have no life at all with the amount of work you put into this. But thanks. :)

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