Sharing The Power

by Sharon Butler

The first time was on Friday, July 23, after Commonwealth Edison made an apparently desperate appeal asking if Fermilab would reduce its power use by 20 megawatts. Temperatures were sizzling, and power demand in the Chicago area was more than the utility could handle.

Under an arrangement Fermilab renewed with ComEd this year, the utility can ask, but the Laboratory doesn't have to agree. If it does agree, however, Fermilab earns a credit on its monthly electricity bill. The credit equals the amount ComEd would have had to pay if it had bought the electricity at market rates from another supplier.

This time, Fermilab's directorate agreed.

And so, Plan 0 went into action.

Over in the Main Control Room, under the direction of Bob Mau, head of the Operations Department in the Beams Division, the major power supplies were shut off to the Booster, the Main Injector, the Tevatron—"essentially anything delivering beam to the experimenters," according to Mau.

By shutting off the accelerators, Mau said, power use was reduced by 15 megawatts in a mere 15 minutes. The trick was finding another five megawatts, which took almost another three hours.

Mau called his "power SWAT team" to help shed power.

Over in the Central Helium Building Liquefier, saving two megawatts of power, Jerry Makara turned off the nitrogen compressor, figuring that Fermilab could always buy liquid nitrogen from a supplier if need be. Fermilab also has a four-day backup supply.

In the CDF assembly hall, Keith Schuh turned off about half of the air-conditioning units. And Tom Kraus, in the Central Utility Building, lowered the setpoint on the air-conditioning for the high-rise offices by 10 percent.

Other "SWAT team" members contributed a few kilowatts here; a few kilowatts there. On a monitor in the Main Control Room, Mau watched as power levels dropped in all the major feeder cables ("I can see if people are cheating, too," he said with a grin). But the levels weren't dropping enough.

As a last resort, instructions were loaded into a computer to shut off the lights in Wilson Hall at 12:30.

At 12:20, in the nick of time, with just 10 minutes to go before the high-rise went dark, a few more power supplies in the Central Utility Building were turned off, and Wilson Hall was saved.

The following Monday, Fermilab once again shed 20 megawatts of power in response to a request from ComEd. This time the procedure was easier. In an hour, the Laboratory had reduced power by 20 megawatts. "Just do what you did on Friday," Mau told the SWAT team.

When Fermilab agrees to give ComEd 20 megawatts of power, said Bruce Chrisman, associate director for administration, it first considers whether the shutdown would jeopardize accelerator operations. On Friday, the accelerators were already down for repairs.

"The main thing we desperately want to avoid is warming up the accelerators," said Chrisman. While restarting the accelerator complex takes a day or two, according to Mau, cranking up the cryogenic system that cools the magnets can take a week. Also, magnets can be damaged if they are repeatedly heated up and cooled down.

Motivation to participate in ComEd's program is in part money. Fermilab can save $20,000 or more per incident. The Laboratory's monthly electricity bill is about $1.5 million. By pitching in, Fermilab might also help avoid rolling blackouts, although ComEd hasn't yet resorted to such a strategy.

"We're one of ComEd's biggest customers in the state of Illinois," Associate Director George Robertson told employees last year. "As a big energy user, we can help our neighbors by becoming a big energy saver."