A Small Utility-Plant Tweak Offers U. of Cincinnati Big Savings

The U. of Cincinnati Central Utility Plant was built in two phases. The older section is in the foreground above, while the newer section is pictured below. (Chronicle photographs by Lawrence Biemiller)

There’s no question that the University of Cincinnati’s Central Utility Plant is a sharp-looking facility. And it’s about to become even more efficient than it already is.

Designed by Cambridge Seven Associates to replace an old coal-fired plant beside the university’s football stadium, the new facility sits on a prominent ridge between the university’s main campus and a residential neighborhood, so its appearance matters to both communities. It opened in two phases, the first in 1992 and the second in 2004. The original section holds a gas-fired steam plant, which serves the main campus as well as the medical campus and some nearby hospitals. The 2004 addition houses chillers and a twin-turbine co-generation system that produces much of the electricity the university uses. Heat left over from the generating process is recycled into the steam system, which both serves winter heating needs and runs chillers for air conditioning.

Joseph Harrell, the university’s utilities director, led an impromptu tour of the plant earlier this week, tossing out facts and figures as fast as I could write them down. Each of the main turbines, for example, generates about 12,000 kilowatts—enough power for about 6,000 homes—and serves the campus far more efficiently than would buying power from the local electric company. That’s because the plant makes electricity near where it will be used, eliminating transmission loss, and makes it at the right voltage, so it doesn’t have to be funnelled through transformers.

Even so, Mr. Harrell says, the university is about to invest $700,000 in a tweak to the plant that he says will cut the university’s electricity use by 1 percent a year. The cooling towers that serve the chillers are currently fed from a big open pool of water in the plant’s lower level, so heavy-duty pumps have to lift the water several stories. The tweak will create a closed-loop system reaching as far up as the base of the towers, eliminating three-quarters of the pumping. The tweak will pay for itself in just four years, he says.

That’s not the only change coming to the plant, Mr. Harrell says. This fall the university will begin buying methane recovered from abandoned coal mines as part of its fuel mix, replacing gas recovered from landfills. Signing a contract to buy the coal-mine gas, he says, gave the small company that recovers it a reliable customer and an incentive to continue expanding its operations. Plus, he says, using recovered gas is better for the environment than, say, using gas from the Marcellus Shale deposits that underlie eastern Ohio, as well as parts of Maryland, New York, Pennsylvania, and West Virginia.

The university has a second, smaller utility plant that still burns coal—which, Mr. Harrell notes, is still significantly cheaper than gas. But coal is also dirtier, so he’s investigating cleaner alternatives, such as mixing coal with wood chips or with pellets made from paper products that otherwise can’t be recycled—labels removed from bottles, for instance, or waxy paper from the backs of mailing labels.

Over the protests of some of his staff members, he’s also working with the university’s College of Engineering, which hopes to try out some new ideas for making coal-fired plants less dirty. The staff members, he says, are afraid the tests will leave them with a soggy mess where their coal fire is supposed to be, in which case they’d face a miserable day or two of shoveling out a boiler by hand. Mr. Harrell says he tells them they may be right, but they are, after all, working for a research university.

The plant’s cooling towers are surrounded by a gleaming—but purely ornamental—stainless-steel screen.