Consumption, Production, and Cost
The Department of Energy and Utilities provides utilities to Georgetown University. See below some general consumption, production, and cost numbers for Georgetown University and the Central Plant. In the following sections, you will find a more in-depth explanation of these commodities.
The Central Heating and Cooling Plant produces and distributes steam to university buildings for space heating, hot water production, cooking, sterilization, and humidification. The campus uses an about 600,000 klbs (kilopounds) of steam. It takes around 14.7 therms of fuel, 3.75 kilowatt-hours of electricity, and 37 gallons of water for our boilers to produce one kilopound of steam. To lend some perspective, it takes around a tenth of a therm to run a standard burner on a gas range stove top for an hour.
The steam produced is driven through underground pipes, driven by approximately 100 pounds per square inch (psi) of pressure. After the steam has been consumed, the resultant liquid (condensate) is pumped back and recycled to produce more steam. The total heating capacity of the Central Plant is 300,000 pounds per hour (pph) of steam.
Chiller 9 being delivered to campus as staff and contractors look on
The Central Heating and Cooling Plant produces and distributes chilled water to university buildings for cooling needs. The chilled water runs through an underground piping system to localized air handling units (AHUs) that use chilled water to produce cool air. The Central Plant produces around 50,000 kTh (kiloton hours) of chilled water a year. As examples, the Intercultural Center uses around 800 kTh a year, the Leavey Center around 2,000, and Village A around 500.
To produce one kiloton-hour of chilled water, our chillers (we have 9) consume around 750 kilowatt-hours and 2,000 gallons of water. Once the chilled water is pumped through the AHUs, it is returned to the Central Plant, where the chillers recool the water by dissipating the heat picked up in the buildings through cooling towers. This takes the form of rising water vapor from the towers at the Central Plant, a process visible from outside. The total cooling capacity of the Central Plant, with the addition of our latest chiller, is 23,500 tons (with an additional 1,000 tons available from our thermal storage tank).
Pepco provides power to Georgetown through six 13.8 kV (kilovolt) main feeds originating from their local electrical substation. Primary distribution throughout campus consists of underground cables and outdoor switchgear rated at 13.8 kV. The campus uses an annual average of 150 million kWh (kilowatts by hours) of power. This electricity is used to power buildings and produce steam and chilled water. Healy, as an example, used 1.3 million kWh a year. About 45 million kWh a year is consumed in the production of chilled water and 1.8 million kWh for steam, with the rest being distributed directly to buildings for consumption.
One of the three high-pressure steam boilers in the Central Plant
Natural gas is delivered to campus by DC’s local utility, Washington Gas. The campus uses an annual average of 750,000 MMBtu of fuel. About 96% of that goes to running the natural gas boilers in our Central Plant to produce steam. The rest is used around campus for miscellaneous natural gas needs in kitchens and scientific labs.
The DC Water and Sewer Authority provides domestic water and sewer services to the campus loop through eight main water lines. The campus uses approximately 300 million gallons of domestic water annually. About thirty-five percent of this water is used in the production of chilled water and about ten percent in the production of steam. This rest of the water runs through the main loop to buildings for local use.