December 3, 2007
Emory Energy 101
Barbara Hudson is manager of training and communications for Campus Services.
What is energy? Very simply put, energy is the ability or capacity for work. Energy cannot be created or destroyed; it can merely be transformed.
How and why do we transform energy at Emory?
At Emory, utilities are used to transform energy to enable the American lifestyle that is well-lit, computer filled, temperate and accustomed to readily accessible drinking water. The transfer of energy into light, or into hot or cool air, produces emissions that can pollute and harm our environment — the main reason we should form new and better habits regarding utility usage.
The utilities consumed in our small city of 30,000 faculty, staff and students, include electricity, natural gas, domestic water, chilled water and steam (measured in kilowatts, therms, gallons, tons and pounds, respectively). In order to get a combined measurement of all utilities used, we must convert each into the shared standard of measurement, BTUs or British thermal units. This is necessary to measure our progress toward reaching Emory’s goal of reducing utility consumption by 25 percent by 2015 from a baseline measurement taken in 2005.
Breakdown of utility usage at Emory
Water is purchased from Dekalb County for chilled water, steam, drinking water and for some irrigation. Whenever possible, the water used to irrigate Emory’s grounds comes from underground cisterns designed to collect and distribute rainwater runoff.
An estimated 67 percent of our electricity is used in the heating, air conditioning and ventilation systems. This is a much higher percentage than for a residence, mainly because at home we do not use ventilation air and tend to cycle the HVAC system on and off. Conversely, code regulations require ventilation fans to stay operational during the hours a public building is occupied. Lighting and plug usage make up the bulk of the remaining third of electricity usage on campus. To produce our electricity, Georgia Power burns coal, also resulting in greenhouse emissions.
Air-conditioning is a complicated process. The cooling process actually removes the heat as well as humidity from the air to “cool” it down. Air feels cooler when humidity is removed, even when outdoor temperatures are the same, the higher humidity in Georgia will make it feel hotter than a dry day in Arizona. To create a comfortable environment with good air quality, a balancing act between heat, humidity and airflow is required.
Chilled water requires a lot of electricity to chill and pump through a coil system, so much so that it gets its own utility category. Additional electricity then is consumed to blow air over the chilled coils into spaces to cool them.
Natural gas is used mainly in steam production, small furnaces to heat spaces, cooking and in research labs.
Steam is considered a utility in and of itself considering the volume that’s produced and consumed on campus, even though it is produced by heating one utility (water) by burning another (natural gas or fuel oil). Among other functions, steam is created to heat buildings, heat water for showers and for sterilization of instruments for research and surgery. The use of fossil fuels for steam production ultimately converts fuel into greenhouse emissions.
Most of the water used to produce steam is circulated within a closed loop system. This means that only a small fraction of the water needed to maintain steam at necessary pressure and temperature levels is “make-up” water, or water purchased from the county and added back into this system. Additionally, county water is treated for human consumption but not filtered to the extent that is required in a steam system. By circulating the existing water, less energy is spent on filtration and treatment.
The United States, per capita, creates more carbon emissions than any other country, by far. One of the reasons we are so interested in energy is what it could mean to future generations.
To produce the environment which we are accustomed to and desire, Emory spends millions of dollars on utilities annually. When we discuss the reduction of energy, what we’re really talking about is reducing the usage of energy or finding alternative methods of transformation so as to produce less carbon emissions, such as using a compact fluorescent vs. an incandescent bulb, and keeping temperature controls between 68 and 72 degrees. Another option is to minimize the transformation of energy, or utility usage, by turning out the lights; walking to meetings where possible; avoid using space heaters; and shutting down computers at night.
The more we “conserve energy” by reducing our utility usage, the less money Emory pays to the utility companies. These savings can then be turned back to fund salary increases, upgrade equipment, put toward new utility conservation initiatives, or whatever else you might have on your departmental wish list.