Beginning this spring, nearly half of the electricity that keeps lights burning and office machines humming on Central Campus and that powers the equipment used in experiments on Science Hill will be generated by the University at its reconfigured Central Power Plant.
The Yale facility has for 80 years been producing the steam that drives the heating and cooling systems of many buildings on Central Campus. With the addition of three new natural gas-fired turbines and other modernized equipment, the Central Power Plant will not only produce steam in a more fuel-efficient and environment-friendly manner, it will also generate up to 18.4 megawatts of electricity for on-campus use.
This new Central Plant Cogeneration Facility is expected to be fully operational by May, according to Thomas Draeger, project director for the power plant modernization program in the Office of Facilities.
Like a trapeze artist practicing a new trick, Draeger is planning to test Yale's new cogeneration system with a safety net firmly in place. During the month of March, he will conduct a series of "failure mode tests" designed to determine whether the facility's emergency backup procedures will operate as expected.
Under the old system, all the electricity powering Central Campus came from the United Illuminating Company (UI), which will continue to supply at least half of Yale's needs through the year 2006. The UI electricity fed the Central and Science campuses via three main switching stations: one was located at the Central Power Plant and supplied the bulk of the Central Campus; a second was located in the Becton substation and fed the Becton Engineering and Applied Science Center and environs; and a third was connected within the Pierson-Sage Power Plant and served the Science Hill area. The latter facility is being decommissioned as part of the modernization project.
Under the new system, both the electricity that UI supplies and that Yale generates will be channeled into a main Cogeneration Switching Station, which will in turn feed this power to users on the Central and Science campuses.
If Yale's electricity-producing facility fails, for whatever reason, this switching station would immediately begin drawing 100 percent of its power from UI.
It is this emergency switch-over system that Draeger and his associates will be testing in March. Workers from Yale and UI will be stationed at critical junctures on the power-supply grid, and the electricity produced by Yale's Central Power Plant will be switched off, as if the facility had gone off-line due to an emergency. This simulated "shut down" will be triggered from various points on the power grid during the course of the tests.
Theoretically, the switchover to full UI power should occur "seamlessly," with nary a blip on a computer screen to indicate to users that anything has happened, explains Draeger. If the expected switchover doesn't occur automatically, the Yale and UI workers can manually throw the switches that will restore power. It is possible, therefore, that there may be power outages lasting several minutes or longer in some areas of campus, Draeger says. These power outages may affect all "normal" power uses within campus buildings, such as lighting and equipment circuits.
While acknowledging that electrical outages can be inconvenient during business hours, Draeger says that in order for the results of the failure-mode tests to be meaningful, they will have to be conducted when the demands for electricity on campus are at their normal levels during the regular work week. "It's quite similar to installing a new electrical service in a home," he explains. "The only way you can test the functionality of a circuit breaker is to actually overload the circuit to see if the breaker trips at the specified point."
In order to reduce the potential for problems and inconvenience, Draeger and his team are establishing a beeper system to inform key people at certain facilities on campus when a failure-mode test will occur. They will also publish information about upcoming tests in the Yale Bulletin & Calendar and the Yale Daily News. "Hopefully, giving people this kind of warning will allow people to make conscious choices and to plan their activities in such a way as to reduce the impact of potential outages," Draeger says.
As a further precaution, the system will be tested in three phases over a two-week period: first, on Central Campus; then, in the Becton Center area; and finally, on Science Hill. (See box, page X.) This plan will hopefully allow any bugs in the system to be worked out before the switchover on Science Hill, where many researchers are conducting ongoing experiments that could be permanently affected by a sustained power outage, notes Draeger. In fact, the number of "safety nets" protecting scientific experiments under the new system will be greater than ever before, he adds.
Even in the unlikely event that the Cogeneration Switching Station should go off-line, Draeger is confident that Yale will continue to be able to supply emergency electricity to campus buildings, thanks to new emergency diesel engines at the Central Power Plant. This "hospital quality" emergency system is linked directly to the UI power grid, explains Draeger, and can also be used as a backup during peak periods of electricity use.
Benefits of new facility
In addition to providing a reliable supply of electricity and steam for heating and cooling, the University's plant modernization program aims to improve the efficiency of fuel conversion to useful energy, to reduce pollution emissions at Yale's plant sites in downtown New Haven and to decrease Yale's operating costs.
The new equipment at the Central Plant Cogeneration Facility will operate at 90 percent fuel conversion efficiency, as opposed to 60 percent fuel conversion efficiency under the old system. In addition to the three natural gas turbine engines mentioned above, the reconfigured plant's equipment includes three heat recovery steam generators, three diesel generators and one boiler that will produce in aggregate more than 300,000 pounds of steam per hour. The peak current steam demand for the Central and Science areas is 220,000 pounds per hour, according to Draeger.
Because the old, inefficient boilers at the Central and Pierson-Sage power plants will be eliminated and because natural gas will be used as fuel in most of the machines, instead of oil, nitrous oxide emissions are expected to be reduced by 85 percent over the old system. In fact, the emissions produced by Yale at its cogeneration facility will be lower in pollution than those created by the UI units currently supplying electricity to the area, thus improving air quality in the city.
All these factors -- cogenerating rather than purchasing electricity, lower fuel expenditures due to higher energy conversion, and the savings associated with the closing of the Pierson-Sage Power Plant -- are expected to significantly reduce the University's operating costs.
Beginning in March, the University will conduct "failure mode tests" designed to ensure that the emergency backup procedures for the new Central Plant Cogeneration Facility will operate as anticipated. These tests will take place in three phases over several weeks: first on Central Campus, then in the Becton Center area and, finally, on Science Hill. The buildings that may be affected by these tests in the various areas are listed below.
All residential colleges except Calhoun
Sterling Law Buildings
Sterling Memorial Library
Cross Campus Library
Beinecke Rare Book & Manuscript Library
Schools of Art and Architecture
School of Drama/University Theatre
Yale University Art Gallery
Yale Center for British Art
Payne Whitney Gymnasium
204, 212, 220 & 232 York St.
205, 211, 217 & 215 Park St.
435 & 451 College St.
68, 80, 82-90 & 96 Wall St.
BECTON CENTER AREA
Becton Engineering and Applied Science Center
Helen Hadley Hall
University Health Services Center
432-434 & 442 Temple St.
Kline Biology Tower
Osborne Memorial Laboratories
Josiah Willard Gibbs Laboratory
Bass Center for Molecular and Structural Biology
Arthur W. Wright Nuclear Structure Laboratory
Accelerator Laboratories #1 and #2
Sloane Physics Laboratory
Kline Chemistry Laboratory
Kline Geology Laboratory
Sterling Chemistry Laboratory
Peabody Museum of Natural History
School of Management
Seeley G. Mudd Library
All Hillhouse Avenue buildings
85 Trumbull St.
155 & 158 Whitney Ave.
124, 135 & 140 Prospect St.
70 & 80 Sachem St.