Can electric utilities keep up with a/c demand?
This year’s July heat wave challenged utilities around the country. For the week ending July 24, the United States set a new national record for electricity consumption. Forty states and the District of Columbia also reached new peaks.
Just seven days later, “the week ending July 31, we broke that all-time national peak by 4.5%,” said M. William Brier, vice president, communication and statistics, for the Edison Electric Institute, Washington.
This time 42 states and the District of Columbia had new peaks. Brier called this heat wave, which covered a “huge” geographic area, “probably the most significant on record.”
Looking overall at electric capacity vs. demand, Brier related that “Generating capacity is declining in terms of the way demand is increasing.
“You have roughly a one-to-one relationship between economic growth and electricity consumption,” he said. If you have economic growth of 1%, you’ll have about the same increase in demand for electricity. “We’ve had 15 years of uninterrupted economic growth.”
With that kind of growth comes a substantial demand for power. However, “there has not been new [power] plant construction, for the most part, over the last decade.”
Since deregulation has been introduced, a number of companies — not necessarily traditional utilities — have announced the intent to construct merchant power plants.
“If all those power plants are constructed, clearly the demand issue would not be a problem,” stated Brier. “However, the construction of power plants is only a piece of the problem. The other piece of the problem is our ability to move the power” — the transmission system.
The latest annual figures available (from 1997) show that utilities spent $11 billion on transmission system upgrades and maintenance. “But what we’re not doing is building a lot of additional transmission” capability, he noted. Utilities have been trying to get more and more out of the existing system.
The transmission infrastructure is vital. “As you bring on new power plant construction, you also have to increase the capacity of the transmission system,” he said. “The transmission system . . . can become a bottleneck if there’s too
much demand on the system and you can’t move the power from the power plant to where it’s needed.”
Not in my backyardIn 1990, Brier pointed out, American Electric Power announced construction of a transmission line through West Virginia and Virginia that would serve customer load and reliability.
They still haven’t built it.
The problem is that nobody wants the line going through their backyard. But tradeoffs have to be made to keep air conditioners, computers, and other electrical devices we rely on humming along under all conditions.
Still, the existing electric generation/transmission system was able to survive July’s unrelenting heat. “The fact that we were able to meet demand based on extraordinary circumstances would suggest that we pushed the system as far as we can push it, but it held up,” he said.
In some cases, demand actually exceeded the capacity of a utility. Some utilities in the Northeast had 5% voltage reductions in effect during a portion of the heat wave. They were also interrupting power (primarily to industrial customers) to those who have interruptible contracts (in return for cheaper electricity).
But every utility doesn’t have to meet its total load all by itself. It can buy power from others.
“That’s why we’re seeing so much sale and purchase of wholesale power between utilities and brokers,” stated Brier. “That should make it more economic and, at the same time, improve the supply situation.”
Lights outDespite all the efforts of the utilities, though, power outages did occur during the July heat wave.
“There were outages in some areas mostly due to equipment failure,” he said. “When it gets this hot and you’re maxing your equipment, and you’re doing it day after day after day, there are bound to be some breakdowns in equipment that can’t be avoided.”
Brier remarked that in a very few places there were rolling brownouts. “For the most part, when you consider the huge geographical region, it wasn’t that prevalent.”
What happens next year if another major heat wave envelops the U.S.? Brier believes it can be managed, but he notes that the merchant power plants announced need to be brought on-line and the transmission system needs to be addressed.
“I don’t want to tell you that, if nothing changes, over the next five years there won’t be problems if this kind of heat continues.”
He added that some of the merchant power plants will be coming on-line next year.
Can the utilities predict when a heat wave is coming? They do try to forecast peak demand periods so they’ll be prepared for them. But their weather forecasters aren’t any more accurate than anyone else’s.
Said Brier, “I had a utility tell me they belong to two different weather services and neither one guessed right on this recent heat wave.” He added, “I don’t think anyone expected the month of July to turn out the way it did.”
And we aren’t just vulnerable during the summer. A severe cold spell in the winter could cause similar problems in the Snow Belt.
What steps can contractors take to lessen the electric load and make their customers’ systems more energy efficient? For one thing, you can simply stress the energy savings of dialing up the thermostat during the summer. For every 1Þ a customer moves it up, they “save about 5% of the electricity needed to run the air conditioner,” Brier noted.
He also recommended using fans with air conditioning. It enables the customer to maintain comfort while dialing up.
The Department of Energy’s (DOE’s) weatherization measures likewise call for the use of fans. Providing ventilation fans — including electric, attic, ceiling, or whole-house fans — increases air circulation.
Other measures include tuning up, repairing, and, if necessary, replacing the air conditioner (or furnace), and insulating the water heater and exposed pipes as well as attic and floors.
Feds weigh inThe heat wave also got the attention of the federal government. Secretary of Energy Bill Richardson announced on July 19 a six-point plan to help prevent major power outages. The DOE initiative calls for:
- Speeding up development of new federal standards for more efficient air conditioners;
- Investigating major power outages and recommending ways to avoid recurrences;
- Assessing whether we have enough electric capacity to meet future demand;
- Coordinating efforts through a Northeast regional summit;
- Leading by example, with the federal government cutting electricity consumption during emergencies; and
- Working to develop advanced generation and transmission technologies.
Brier stated that the DOE’s planned new standards raising the efficiency level of air conditioners “would allow you to have the same amount of air conditioning using less electricity.”
Rulemaking is being moved forward on this “by six to nine months.” It is expected that the current 10 SEER minimum will be raised to 12 SEER. Since manufacturers can build units to higher ratings, this will save energy without putting undue pressure on the capabilities of the industry.