The Grid: Electrical Infrastructure for a New Era

by Gretchen Bakke

Higher-voltage towers are usually made of aluminum, a weak metal that is not necessarily the best choice for areas expecting occasional direct hits by hurricane force winds. These are slowly being hardened as aluminum is replaced by galvanized steel or concrete. Substations are being moved to higher ground in easily flooded areas and distribution lines are being buried in areas susceptible to severe weather but not to flooding.

Gas stations dispense fuel by means of electric pumps, making supplies of liquid fuel for cars and airplanes also at risk when the grid breaks.

Soft energy technologies, the adoption of which they considered to be the first necessary step toward ensuring energy security in the United States, have five defining characteristics. First, they rely on renewable energy resources, like wind and solar, but also biomass, geothermal, wave, and tidal power. Second, they are diverse and designed to function with maximum effectiveness within specific circumstances. Third, they are flexible and relatively simple to understand. Fourth, they should be matched to end-use needs in terms of scale, and fifth, they should also be matched to end use in terms of quality. All of this is nested within a larger cultural commitment to energy efficiency that is built in to our structures and our life-ways from the ground

Renewable energy resources don’t need risky supply chains—like the chance arrival of a fuel truck in the middle of a hurricane—in order to function. Because it is more difficult (though far from impossible) to disrupt their functioning they are by their nature more secure.

Unlike Edison’s private plants, these modern microgrids can connect and unconnect as needed to the big grid (which is now increasingly known as the “macrogrid”). And, unlike any system since the consolidation of power in the early twentieth century, these microgrids work perfectly well in “island” mode.

Not nanogrids (home-sized electrical systems that allow one to effectively live off the big grid), microgrids always have multiple sources of generation. These work to diminish the fragility of their supply chain, whether from oil embargoes or long spates of unexpected cloud cover. They also by definition have multiple customers—or meters—drawing, ideally, a diverse load from this little grid.

this means that most microgrids include large banks of batteries as well as some way to control load on the “demand side” (so-called controllable or sheddable loads). This usually means the ability to remotely shut down nonessential power-consuming devices like air conditioners or clothes dryers.

Though one can run a microgrid on 100 percent stock (nonrenewable) fuels, most also embrace a modest amount of renewable generation. NYU’s is powered by a natural-gas-fueled combined heat and power (cogeneration) plant.

Because of the need for resiliency—which is to say, many ways of making power, many ways of delivering it, and many ways of using it, all of which can be adjusted in a pinch—almost all microgrids incorporate some form of renewable generation.

“at three hundred thousand barrels a day the Department of Defense is one of the biggest users of oil. Getting that fuel to the front lines is incredibly expensive—in dollars but more importantly in blood.”

the transportation of liquid fuel into Afghanistan is so dangerous that the military prefers to fly in thousands of pounds of new disposable batteries than to truck in the gasoline that would be necessary to run the generators to rejuvenate rechargeables already in place on the ground.

One estimate is that 70 percent of the gasoline actually used in the field is for transporting other gasoline around. Tanker trucks have to be fueled the same as any other vehicle.

in the West and Midwest, where the space between communities is large and filled with quiet, the theft of copper grounding wire from substations has reached epidemic proportions. Sometimes the same substation is stripped of its copper several times in a month, the copper spirited away almost as fast as the utility can reinstall it. Transformers, which are wound with the metal, fall no less victim to the nimble fingers of copper thieves.

As a “clean” energy source, fusion produces no radiation, it uses a neutral isotope found in water as its fuel, and the reactor that produces it can’t melt down. With fusion we would have a limitless source of nonpolluting power.

The problem is that it takes about as much electricity to run a fusion reactor as that reactor produces. It is a zero-net-energy machine; the power that goes in equals the power it spits out. Nevertheless, for over half a century, fusion has been the electricity industry’s holy grail: limitless power from water.

What counts as the holy grail changes as our visions for a more perfect future are themselves transformed by present-day concerns. Today the grail is less a new way to make power than it is to find a really good way to store it.

For the moment we solve this problem by doing things backward. Rather than storing excess power we use generation to “balance” generation. Every time a cloud goes by and diminishes solar output for a second or two, we burn some fossil fuels to generate enough little jolts of electricity to even out the electron flow.

It could be a year, or thirty years, later, and the electricity would be just as fresh as when it was plucked from the air. As odd as it sounds, this is precisely how oil and coal work today. It doesn’t matter when or where they were extracted, and it doesn’t matter how long it takes for us to get around to using them. They can wait.

For places with mountains, there is “pumped hydro.” It’s a sort of man-made dry lakebed near an existing hydroelectric dam. When there is too much water, whether run-off or rain, some of the electricity the dam makes is used to pump the excess water uphill, into a second reservoir, where it sits until additional power is needed, then this water is allowed to flow naturally downhill again passing through a set of turbines at the bottom to generate a “new” electric current. Ninety-five percent of the electricity “stored” in the United States is guarded in this way—22 gigawatts’ worth or the equivalent of 2 percent of our national generating capacity. Pumped hydro works great in places with hills and dammed rivers.

A couple of Gulf states do have something as useful for electricity storage as a hill near an existing reservoir. Alabama and Mississippi have salt domes. Starting just north of Mobile and stretching all the way under southern Mississippi are a warren of natural salt caverns long used for dumping toxic chemical waste. These can be just as profitably used to store compressed air. This is precisely what the CAES plant, in McIntosh, Alabama, does. When electricity is cheap or there is too much of it, usually at night, the excess is used to condense air and force it into these caverns. Then, during the day, when demand is high, the air is released. As it expands, or decompresses, it spins a turbine to regenerate an electric current. Unlike pumped hydro, however, this air isn’t storable indefinitely.

Another even more recent stab at energy storage has come in the form of concentrating solar towers.

An array of mirrors is situated in a sunny place, usually a desert, with all of their angles adjusted such that their individual beams of sunlight are directed at a looming central tower filled with something rather like table salt, which liquefies

The sun’s daytime heat is stored in the liquid salt until needed, and then that heat is used to boil water, which drives a normal steam turbine to generate electricity.

Solar trough plants, some of which also have molten salt storage, are good for about six hours of power production after the sun sets.

home or business owner, considering the empty and non-profitable space of her roof, calls a panel company, which comes out and waves something rather like an iPad-on-a-stick around on top of the house and from this determines what portion of the roof would need to be covered in photovoltaic cells in order to offset actual electricity use. Then they offer a package that spreads the cost of these panels over a set period of time, in the neighborhood of 240 months. This rate per month is designed to zero out a panel owner’s electricity bill, and it is usually about what a customer was paying to their utility to start with.

utility attempts to get reasonable line access fees or standby fees (that allow solar panel owners to use grid-provided electricity when their systems fail) passed in states with high solar penetration have foundered.

The true owner of the panels is the company from which they are leased and they cover all installation, maintenance, and equipment costs in exchange for the right to collect state and federal renewable energy subsidies. They also receive payments from the customer over the life of the lease.

the bit of the grid designed for distribution—the low-voltage wires slung between homes and pole tops in residential neighborhoods. Ironically, this is also the weakest part of the system, the most likely to give way, and the least well kept up.

transmission systems—those long high-voltage lines that stretch between distant power plants where electricity was once solely made and the urban centers where it is still mostly used—are much less prone to outages.

This is what is meant by the utility death spiral: “as grid maintenance costs go up and the capital cost of renewable energy moves down, more customers will be encouraged to leave the grid. In turn that pushes grid costs even higher for the remaining customers, who then have even more incentive to become self-sufficient.”

Batteries, despite their ability to produce electricity on call, don’t actually have electricity inside them, instead they are full of chemicals. Under the right conditions these chemicals can be coaxed into a reaction that causes chemistry to produce electricity. In order to work, each of a battery’s two “terminals” has to be made from a different kind of metal separated by an electrolyte. Any number of things can serve as an electrolyte, from soda pop or a potato to sulfuric acid or even ceramic, though various kinds of salts and acids generally work best. Regardless of which electrolyte and which metals one chooses, a battery works because positive ions move in one direction through the electrolyte, effectively peeling off infinitesimal bits of the metal from one pole and sticking them to the other. Electrons simultaneously move in the opposite direction.

battery can be made, sit in a package for years (though not indefinitely), and still be useful when popped into your TV remote or hearing aid or electric car. Though it won’t work forever; the electrolyte solution will get tired, and as one of the metals is slowly eaten away while the other grows heavier, the battery lags and then ceases to work at all. A rechargeable battery reverses the direction of flow, using electricity from an outside source to move most (but not all) of the ions and accretions back to the other side, where they will be ready to flow back again when conditions demand.

“For an illustration look at Hawaii,” writes the Economist. “On a typical sunny day the panels on consumers’ rooftops produce so much electricity that the grid does not need to buy any power from the oil fired generators that have long supplied the American State. But in the morning and the evening those same consumers turn to the grid for extra electricity. The result is a demand profile that looks like a duck’s back, rising at the tail and neck and dipping in the middle.”

To solve this new kind of curve, the utility doesn’t need twenty-four or even twelve hours of storage capacity; they need about six hours’ worth to get them from four P.M. to ten P.M., when people start slowly trickling off to bed.

One recent author described the project of overhauling the grid as akin to “rebuilding our entire airplane fleet, along with our runways and air traffic control system while the planes are all up in the air, filled with passengers.”

Today’s fridges use about a quarter of the power they did in 1975.

The grid, as should be clear by now, is not a technological system. It is also a legal one, a business one, a political one, a cultural one, and a weather-driven one, and the ebbs and flows in each domain affect the very possibility of success of any plan for its improvement.

(Not “less-is-more,” mind you, but “the same with less.”) At

Computing has given us the capacity to tear the heart right out of the center of our grid. It doesn’t need a heart. It can work with a million hearts, or a hundred million, scattered to the four winds and brought into balance by reactive, sensitive, ubiquitous software.