Hydroelectric Energy in Western North Carolina

Did you know that hydroelectric energy accounts for about 5% of North Carolina’s total energy production? In fact, it is the second-largest source of renewable electricity in the state, falling behind solar energy for the first time in 2017. There are close to 40 utility-scale hydroelectric dams in the state and the majority of these are located in the mountains of western North Carolina.

Fontana Dam is the closest major hydroelectric powerplant to Sylva, located in Swain and Graham counties about 30 miles from Bryson City. It is the first of five dams on the Little Tennessee River, followed downstream by the Cheoah, Calderwood, Chilhowee, and Tellico Dams. Hydroelectric powerplants produce electricity using the force of falling water. The amount of force, or potential energy, the water has as it accumulates behind a dam is dependent on the volume of water and the height that it will fall. In this context, Fontana is the tallest dam in the eastern United States at 480 feet tall and has a water storage capacity of 630 million cubic meters! When the gates are opened, this potential energy is converted into mechanical energy and turns the rotary blades of a turbine. The rotating turbine generates electricity by spinning electromagnets in stationary coils of wire. The three generators at Fontana have a combined capacity of about 300 megawatts and the water level varies by 57 feet annually.

Hydroelectric power has a number of advantages. It is renewable and does not generate any greenhouse gas emissions (after construction of the dam). The lakes that are created by hydroelectric dams are often used for drinking water and recreational purposes, providing an economic boost to local communities. In addition, hydroelectric power is reliable and adjustable, meaning that it pairs well with other renewable energy sources because the flow of water can be readily changed to produce more or less electricity to meet energy demand in real-time.

There are some drawbacks to hydroelectric energy, however. Most of the best locations for hydroelectric dams have already been utilized and thus the potential for new dams is limited. Hydroelectric power is susceptible to droughts, as we are currently seeing with Lake Mead and the Colorado River out west (Hoover Dam). And, the upfront investment cost for constructing a dam and acquiring all of the necessary land for the reservoir is quite expensive. Fontana Dam had a price tag of $70,420,688 upon completion in 1944 (that is just over 1.054 billion dollars in today’s money, which actually sounds like a bargain!).

Dams also disrupt the natural flow of a river system, which affects fish migration patterns and other animals that depend on those fish for food. River habitats are lost, the downstream water supply is diminished, and other wildlife habitats are lost as land is submerged to make the reservoir. Likewise, entire communities can be displaced. Lake Fontana covers 10,230 acres and 5,125 acres had to be clear cut during the construction of Fontana Dam. In addition, 1,311 families and 1,047 graves had to be relocated from the now submerged towns of Fontana, Bushnell, Forney, and Judson.

However, there are significant environmental and economic benefits that are gained as well. Each dam must be considered on a case by case basis. There is no doubt that Lake Fontana is a beautiful mountain lake that continues to be enjoyed by thousands of people every year and has provided clean and reliable electricity for almost 80 years and counting. According to the Hydropower Reform Coalition, Fontana Dam generates an average of 899,771 megawatt hours of hydropower each year, which is equivalent to the average annual electricity consumption of 84,493 American homes! Put another way, this clean electricity offsets almost 640,000 metric tons of CO2 emissions each year according to the EPA’s greenhouse gases equivalencies information!

Jonah W. Jurss, Ph.D. is a chemistry professor at the University of Mississippi who does research in the field of renewable energy. He joined the Department of Chemistry and Biochemistry in 2014.