18. Smart Grid: Your Future Friend?
Smart Grid: Your Future Friend?
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 (and I'm lazy)
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: At this rate, this is going to be a lonnnggg conversation...
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 plusses, 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.
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