Purdue News

Need to expand steam capacity growing as campus adds buildings

From Inside Purdue

Steam capacity in the West Lafayette Campus utility system is straining under the demands of cold weather and newly constructed buildings, officials say.

Physical Facilities is working on two possible ways to make more steam available – buying it from a third-party supplier or seeking $40 million in state money to build another coal boiler this decade.

"It will be part of the 10-year capital request being considered by the trustees this week," Wayne Kjonaas, vice president for physical facilities, said before the trustees’ meeting Friday.

To make the project possible, the request also includes $1.5 million for detailed planning – money needed in 2005.

The subzero spell at the end of January illustrates the problem and its increasing scope, Kjonaas says.

"Our three coal boilers were running at maximum capacity, and we ran the gas-oil boiler, he says. "Further dependence on natural gas would drive up our costs."

On those bitter January days, he says, the hourly cost penalty was about $370 per hour and the difference in steam cost was a factor of more than four at $7.31/mbtu (million BTU) with gas vs. $1.67/mbtu with coal.

On Jan. 30, "we set a new record peak steam load with a one-hour average load of 556,000 pounds per hour and a peak of 570,000," Kjonaas says.

That tests the limits of what engineers call "firm capacity," he says, explaining, "Firm capacity is calculated by figuring your total capacity and then subtracting your largest unit."

The result shows what a facility such as Wade Power Plant can do if any single unit goes down.

"Two of the coal boilers were built in 1959 and 1960," Kjonaas says. "If they’re supplying two-thirds of the steam capacity, that leaves us vulnerable."

The cold snap was not, however, a worst-case scenario, says Erick VanMeter, director of utilities.

The temperature during the peak hour (11 a.m. to noon Jan. 30) was minus 1.8 degrees. That’s far from the coldest imaginable for the area.

"If we had had minus 15 degrees instead of minus 1.8, the load would have been 585,000 pounds per hour," he says.

At either point, the increasing demand because of additional buildings is tilting the equation.

"The coal boilers can produce 575,000 pounds per hour," VanMeter says. "When it gets down to 5 degrees, we start up the gas-oil boiler to have backup. And it’s getting to where we’ll have to run it just to meet demand, not as backup.

"We’ve already passed the point where we no longer have firm reserve capacity."

That is to say, he adds, when all four units are needed just to keep up, there is no fallback if a unit has a problem.

Demand, cost and even availability of natural gas at affordable prices will become more challenging as the campus grows, Kjonaas says, accentuating the value of adding steam capacity.

"With the nanotechnology center and other facilities in Discovery Park coming on line next year, we will begin to see much more of this, which is exactly what our projections have shown," Kjonaas says.

The growing problem did not sneak up on the University. In 1999, Physical Facilities engaged an engineering consulting firm whose recommendations included increasing steam capacity by 2005.

The firm also strongly advised Purdue to continue producing its own steam, VanMeter says.

In the intervening years, Purdue has increased its efforts at efficiency. The University was the first state entity to reach the original $10 million borrowing limit for conservation spending under Indiana’s Qualified Energy Savings Program, begun in 1998.

That has allowed Purdue to delay adding a boiler, VanMeter says, but the grace period is dwindling as more buildings open – having the boiler or an alternative source of steam by 2007 would be helpful, but Purdue must have it by winter 2009.

Purdue also has controlled heating costs by buying natural gas before the heating season at better prices. Thus far this fiscal year, the price has averaged $4.86/mbtu, VanMeter says, but if Purdue had waited until high-need periods to buy, the price could have been above $10/mbtu.

In one major thrust to meet needs at the lowest possible costs, Purdue has invited bids from steam vendors. The deadline is March 10.

That date will open a period of negotiation, which, if fruitful, could lead to Board of Trustees approval of a contract by fall, VanMeter says.

But since Purdue has no guarantee of success on that path, officials also are working out plans for a fourth coal boiler estimated to cost $40 million.

"We would need to have the money released at the start of the 2007 fiscal year," VanMeter says. "Construction would take 18-24 months, provided we have our engineering work done ahead of time."

And to reach that point, Purdue has determined, the $1.5 million state appropriation in 2005 for planning the project is essential – unless steam purchasing for a period of years turns out to look far more promising than it does now.