Building owners concerned about rising air-conditioning costs this long, hot summer are turning to a novel method of cooling their buildings: They are making huge piles of ice in their basements at night when electricity prices are cheap, and using the ice to cool the building during the day.
The nighttime "slushie" machines cut daytime energy use by so much that local utilities, hard-pressed to meet demands for power on July and August afternoons, are paying building owners as much as $100,000 to install them.
Ice machines and special holding pools have been installed in buildings as diverse as the new McCormick & Co. headquarters being constructed in Sparks and the 69-year-old Legg Mason building on East Fayette Street in downtown Baltimore.
Though tenants of some ice-cooled buildings complain that their systems were overwhelmed by mid-July's 100-degree days, building managers statewide are being lured by the utilities' incentives as well as the chance to cut summertime electricity bills by as much as a third.
Greg Leverton, who manages the Legg Mason building for W. C. Pinkard & Co., said the 1988 installation of a $650,000 ice-making machine has saved $450,000 in summertime electricity bills.
And because electricity prices have been rising recently, Mr. Leverton said that he expects the machine to pay for itself faster than planned -- in a total of four years.
The key to the savings, he said, is that the Baltimore Gas and Electric Co. charges as much as 4.4 cents per kilowatt hour for electricity during hot summer days, but only 1.9 cents per kilowatt hour during summer nights. A kilowatt hour is enough electricity to light 10 100-watt light bulbs for one hour.
Pinkard bought a system that dumps ice into a basement pool from 6 p.m. to 6 a.m., then pumps the icy water from the pool into pipes during the day. Because it takes much less electricity to pump the water through the pipes than it does to make the ice, the company's daytime power usage has been cut by about one-third, Mr. Leverton said.
Though Pinkard installed the ice machine before BG&E started offering cash incentives, a growing number of companies are being lured by programs such as BG&E's "Cool Reserve" rewards.
Since last year, BG&E has offered to pay as much as $15,000 in reimbursements to companies that investigate and install the ice-cooling systems and another $200 for every kilowatt of power the company shifts from daytime to nighttime usage after the system is installed. Potomac Electric Power Co., the utility serving Montgomery and Prince George's counties, has offered to pay up to $5,000 for studies and $250 per kilowatt since early 1990.
By the end of this year, BG&E will have paid a total of $500,000 for seven new ice systems, including machines at McCormick's new headquarters and at Union Memorial Hospital.
The utilities are eager to pay for installation of more of the ice machines so businesses will turn off power-hungry air conditioners during the day, when demand for electricity is highest, said John Murach, the BG&E executive in charge of the program.
BG&E saves more than twice the $200 payment if it can avoid building expensive generators to serve the peak daytime
demand, said Arthur Slusark, a company spokesman.
But not everyone is hot on the ice coolers. Though they like the idea of saving money and electricity, some Legg Mason tenants aren't thrilled with the machine's performance.
Nancy Childs, office manager for Western Temporary Services on the 14th floor of the building, said that during a recent week of 100-degree-plus afternoons, her staff began to wilt as the room temperature reached 85 degrees.
"We bought fans and had to hold everything down on our desks. . . . It stayed pretty sticky," she said.
The system does "get a little overburdened" on especially hot days, Mr. Leverton conceded. But every system downtown was having problems at the time, he said.