Something is traveling around campus beneath your feet. At any given time, up to 350,000 pounds of steam per hour is moving underneath the sidewalks and other parts of campus, said Bill Serencsits, an Office of Physical Plant (OPP) utility systems engineer.
Paul Moser, OPP superintendent of steam services, said the West and East Campus Steam Plants provide steam for heating all campus buildings, for hot water and for sanitation in laboratories.
The steam is also used to generate 6 to 7 percent of the university's total electricity and is ready to be used as emergency power for the entire campus if needed, he said.
These plants are powered by coal-fired boilers -- four at the West Campus Steam Plant (WCSP), between Burrowes and Atherton streets on the southwest corner of campus, and two at the East Campus Steam Plant (ECSP), south of Beaver Stadium.
Combined, they burn about 7,500 tons of coal per year (depending on the weather) at about 2,600 degrees Fahrenheit, Moser explained.
The boilers produce super-heated steam near 540 degrees Fahrenheit, which is then depressurized and cooled before it is delivered to campus, he said.
The steam generated from this process is then sent throughout University Park in steam pipes, some of which are located in steam tunnels that run underneath the campus and are big enough to walk through, Serencsits said.
Moser said coal is delivered every day to the WCSP from Clarion County and is loaded into a hopper, a type of conveyor belt, which carries the coal to the top of the building where it is placed in a 900-ton-capacity bunker to be distributed into the boilers.
Each boiler, towering 35 to 40 feet high and 15 feet wide, is programmed to shake periodically, causing the coal inside to slide slowly down a grating in the boiler as it burns in the furnace, which heats water located in drums in the boiler into steam.
This combustion process super-heats the steam and pressurizes it to about 250 pounds per square inch (psi), Moser said.
The high-pressured steam is sent through turbines to generate electricity, which lowers the pressure of the steam. At this point, the steam is delivered to campus, and excess water is recycled back into the plant to be reused, he explained.
Serencsits said the steam is then carried through a 2.5-mile loop of steam pipes throughout University Park at both low and high pressures.
Many of these pipes are in tunnels directly under campus sidewalks, he said. The vents commonly seen on the sidewalks serve to keep the tunnels from overheating and to keep the tunnels ventilated for workers.
Paul Ruskin, OPP spokesman, explained that heated sidewalks are a benefit of this system.
"Our primary purpose was not to heat the sidewalks," Ruskin said. He added that underneath the sidewalks "was just a convenient place to put the tunnels, and the heated sidewalks are just a by-product of our operation."
Moser said steam tunnels are inspected monthly, and the boilers are inspected during the summer months, when only two of the four boilers need to be operating at the WCSP.
Operations of the steam plants are conducted in such a way to be as earth-friendly as possible, he said.
"Our main goal here at the steam plants is efficiency," he said. "We want to use as much of the heat that we make as possible."
Moser said great care is also taken at the plants to collect the coal ash. The solid ash is collected and then donated to municipalities in the Centre Region for anti-skid material.
The ash and other harmful chemicals in the exhaust are collected in Gore-Tex bags that are eight inches in diameter and 20 feet long. The bags act as filters, collecting ash and other byproducts, Moser said.
This system collects 99.9 percent of ash and other agents, and the large smokestack at the WCSP almost never has exhaust of any type coming out of it, except on the coldest days when some water vapor can be seen escaping, he explained.
Ruskin said Penn State spends a lot of money to remove this particulate matter from the boiler exhaust.
Serencsits said the university's steam plants operate as good as or better than any other facilities of this type and meet all emissions and environmental standards issued by the Pennsylvania Department of Environmental Protection.
For the most part, this is thanks to the steam plant's staff, Moser said. Because of its necessity to Penn State, steam generation for campus is a 24/7 operation, he said.
Ruskin said that OPP has committed to developing new strategies to slowly cut the amount of steam produced by coal on campus.
"OPP is concerned about the long-term energy needs of Penn State, and we are developing a master plan for energy where the economic needs of the university are weighed with ecological needs," he said.
Serencsits explained that as part of the OPP energy master plan, exploring alternative fuels will soon begin, including using the biomass generated on campus to heat the boilers at the plants.
Even as alternative fuels are adopted, the campus steam plants will still have a crucial role in the function of the university, Moser said.
"Penn State continues to grow around [the steam plants]", he said. "This is why we developed the energy master plan, and now, as we experience growth, we can be pro-active in what we do and how we do it."
To further cut down on energy consumption, Ruskin said students can help save energy by turning down thermostats in unused classrooms and taking shorter showers to conserve hot water.
