The Grid: Electrical Infrastructure for a New Era

by Gretchen Bakke

Peak load is the utilities’ nightmare; it happens once or twice every year, and it’s always a scramble to make sure things don’t go disastrously awry every single time. This is why it would be useful to the utilities if people have smart meters that can both monitor usage and be used to control it in times of systemic stress. It is also why utilities like Consolidated Edison in New York robocall pretty much every one in the five boroughs on particularly hot summer days asking residents to pretty please turn down their air conditioners else risk setting off a citywide blackout. Many people rightly suspected from the start that “smart meter” actually meant “device for remotely controlling residential air-conditioning” even back when the official line was that it wouldn’t ever be used to such Big Brotheresque ends.

Most of the time customer usage is fairly predictable. Refrigerators, for example, are always on, and use about 14 percent of domestic power. Freezers use another 4 percent. Based on this data, the utility can bank on needing to make and transport a certain baseline of power all the time. This is one of the advantages of nuclear power plants. They may be difficult to ramp up or down quickly, but since they provide 20 percent of American power with exceptional reliability, they are basically big machines for transforming plutonium into refrigeration.

Still other things are culturally predictable. Between five and six P.M., Americans tend to come home from work. When this happens we use all kinds of electrical devices we weren’t using before: big TVs, microwaves, washing machines, and garage door openers. On average we open our fridge nine times in the hour before dinner. All of these things add up to a fairly substantial jump in demand from just after the close of the workday until about ten P.M., at which point demand begins a slow downward slide that ends at four A.M.—the hour of minimum load. To meet this steady bump in demand, power plants ramp up everywhere in America just before five P.M. Unfortunately, it is also when the wind tends to slow down and, at certain times of year, when the sun starts its setting, making renewables without backup storage the least useful means of producing power at the most necessary moment of the day.

Because we still lack a good system for storing renewable power, America’s evenings are powered by coal, natural gas, and the ever-present baseline of nuclear.

As American homes get bigger, as population shifts toward the southern states, and as air-conditioning becomes ubiquitous in all new construction, the summer peaks have grown steadily graver than those in winter.

Some blame can also be apportioned to global warming: thirteen of the fifteen hottest years on record (since the start of record-keeping in 1880) have been since 2000, with 2015 being the hottest year ever recorded. Even though summers are getting hotter, driving up air-conditioner usage nationwide, there have also been some spectacular cold snaps as well, the polar vortex in 2014 being among the most memorable in recent times.

The air conditioner is here to stay. And, as Fleishman, quoted above, succinctly points out: “Anywhere there’s air-conditioning, smart grids will likely prosper.” This is not just because these devices use a lot of electricity (they do), but because everybody uses them at the same time and because when it’s very hot outside the utilities are already having a difficult time for a variety of reasons: long-distance wheeling goes up, spot markets get expensive, and lines sag and grow less efficient.

More expensive and more socially and technologically complex are incentivized “opt in” programs like the one Pepco runs in Washington, D.C. These give modest cash payments to individual households, usually in the neighborhood of forty dollars a summer, in exchange for “letting the utility automatically control their air conditioners on the few summer days when system demand is highest.” Xcel has started something similar in Colorado. Their program is called the Saver’s Switch, and it involves a small device that resembles a beeper of old, installed by the utility on the outside of your house, just next to the central air-conditioning unit. This device allows Xcel to wirelessly switch the air conditioner off and on as needed throughout the summer. The program is touted as being “100 percent free to you.” Plus, like Pepco, Xcel pays you forty dollars for participating.