Here’s how today’s conversation about The Grid between the English major and the Physicist began.

English Major:  Sooo, if amps are “current,” what are volts?

Physicist: I can’t explain that, it’s too complicated.

EM: No, I mean, isn’t there a word for what volts are, like “current” is what amps are?

P: Yes, “volts.”  Volts are volts. That’s why it’s complicated.

EM: Well, I mean, like what do they do? Do they, do they – (shot in the dark:) Do they just push it or something?

P: Yah, they push it, that’s what they do, fine.

EM thinks: Getting that push was like pulling teeth. This isn’t starting well…

Last column we talked about The Grid in a simple enough way that the less technically inclined of the two of us could construct true sentences about it. While this proved interesting and the English Major may have learned something useful and perhaps even memorable, still the thrill was minimal. The Smart Grid, though a bit more alluring due to its admixture of magic and menace, didn’t quite fit in the word limit, so we promised to visit it later.  Here goes.

As previously explained, the grid is a very complex interconnection of electricity-generating facilities, high voltage transmission lines, substations, lower voltage distribution lines and connections to homes, businesses, and industries.  Because of this complexity, it is not a simple matter to make it as efficient as it might be.

For instance, sometimes more supply of power is needed than usual, and the way the grid works now, more generating stations need to be turned up or switched on.  Some of these are more expensive and less efficient, and exist only to supply this peak power. What if there were a way to reduce the demand during these peak times, instead of increasing the supply, thereby reducing the need for additional sources?

Cue the Cavalry bugles, enter Smart Grid. A smart grid incorporates a two-way communication system between and among power suppliers, distributors and end users.  It also interacts with “smart” meters and “smart” appliances. While the Smart Grid is something that is only in development right now, an important element of it is in place already – the Smart Meter.

EM: Wait, smart meters – is that the weird little green light out on the shed wall I see at night? Actually, don’t those cause cancer – or send your shopping data to the Chinese? Pretty sure I heard that.

Physicist:(pause) …

EM: Never mind, go on –

Right now, smart meters are able to communicate with the electricity supply and distribution companies, allowing them to do such things as determine, in real time, where demand is, or immediately see if there is an outage. They also make it so they can figure your electric bill without having a meter reader come by your house.  For the consumer there are also some pluses, such as, you can actually look at your usage on the internet – you can look at hour by hour usage that gets updated daily, allowing you to see when and where your electricity is being used! (P’s eyes get far-away dreamy look)

EM: Get OUT, really?! (egad).

So ultimately when the smart grid is in place it will consist of a communication and control system that uses smart meters to control demand in response to supply. It will be possible for the grid to reduce power from a few thousand domestic water heaters or electric vehicle chargers to supply peak power for more immediate needs.

EM: Whoa – Wait, what?  Some spawn of Siri and Hal (2001 Space Odyssey reference – OK, Boomer) infiltrates my house, my neighborhood, my state, and turns my hot shower cold ‘cause it has other priorities??

P: No, no, no – Just breathe, will you?

Because the smart grid would be able to respond almost instantaneously to demand changes, consumers would mostly not even notice. In other words, by spreading the reduction in demand throughout the grid, among all the users, the fluctuation would be minimal.

(Yah, I still remember the part where Dave needed Hal to unlock the hatch.  But for argument’s sake, whatever. The Smart Grid will be competent and benign, yup.)

The smart grid will also be able to respond rapidly to changes in supply from renewables such as wind and solar.  Since supply always has to precisely match demand, any fluctuation in production by renewables needs to be compensated for. As the smart grid gets built up, it will include very substantial short term storage in the form of batteries and hydroelectric plants, which can be turned off and on far more quickly than coal or nuclear plants, so can respond better to fluctuations in both supply and demand.

Right now, battery storage is very limited, but it’s growing rapidly as technology evolves. With the smart grid some of that battery power can even be provided by electric vehicles in their home charging stations. These fluctuations can also be leveled off with long distance high voltage DC power lines that interconnect different synchronous grids.

Which brings us back to the first part of today’s Physicist-English Major colloquy – power lines, AC and DC, transmission losses, and other definitely useful things to know if you want to pontificate about the future of power in our society.  So stay tuned for the next installment of Energy Matters.

Paul Stancioff, PhD., is a professor of Physics at the University of Maine Farmington who studies energy economics on the side.  He can be reached at pauls@maine.edu. Cynthia Stancioff likes to re-word things. Previous columns can be found at https://paulandcynthiaenergymatters.blogspot.com/

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