About the Bad Creek Project
One of Duke Energy’s newer hydropower plants, construction of the 1,400-megawatt Bad Creek Project took roughly 10 years and was completed in 1991.
How the Bad Creek Hydro Station Works
Hydroelectric power is generated using the force of moving water. During times of peak electricity demand, water is released from the upper reservoir at the top of the mountain. The water rushes down a concrete intake tunnel that travels nearly three-quarters of a mile to the underground powerhouse. The force of the water spins huge turbines, which are connected to large generators that produce electricity within minutes. The water then flows through a discharge tunnel into the Whitewater River cove on Lake Jocassee. When there is excess energy on the power grid, including periods of high energy generation from solar sources, energy from the grid is used to power the turbines to pump water from Lake Jocassee back to the upper reservoir.
An Evolving Project Purpose
The existing Bad Creek Project was designed in the 1970s and 1980s to generate power by lowering the reservoir on weekdays during peak energy usage times. The upper reservoir was refilled at night and over the weekend with low-cost extra energy from coal and nuclear plants.
As the mix of energy generating sources has changed in the decades since it was constructed, so too has operation of the Bad Creek Project. Today, plant operations alternate between generating and storing (pumping) energy daily. This helps balance the regional transmission system during changes such as rapid generation of power from solar sources. Current operations only use about 30% to 40% of the storage capacity of the upper reservoir.
A second underground powerhouse of equal size would allow the Bad Creek Project to generate or store more power during daily operations.
Proposed Project Expansion
The Bad Creek II Power Complex would roughly double the existing power generation and storage (pumping) capacity. The new facility would transfer water between the existing upper reservoir and Lake Jocassee. The project expansion would include a water intake/discharge structure within the existing upper reservoir, underground water conveyance system, underground powerhouse, and water intake/discharge structure along the shoreline of Lake Jocassee, adjacent to the existing structure.
Duke Energy currently owns the property required to build the Bad Creek II Power Complex. A preliminary layout of the expanded project facilities is shown here. This layout will continue to be refined as we advance technical and economic studies for the Bad Creek II Power Complex. The locations of new structures and disturbed areas have and will continue to be sited to help reduce impacts to natural resources.
The Value of Hydroelectric Pumped Storage
Today, hydroelectric plants provide about 8% of Duke Energy’s power capacity in the Carolinas and, along with solar photovoltaic installations, play an important role in bringing more renewable energy onto the power grid. With the ability to quickly go from zero to maximum power generation output, hydroelectric plants are ideal for meeting sudden changes in electricity demand. They can also help balance the power supply to keep the electric grid stable and reliable. Hydroelectric power remains a critical part of Duke Energy’s diverse generation mix and is vital to delivering low-cost and reliable electricity.
Clean Energy Transformation
The Carolinas are among the fastest-growing states in the country. As the population continues to increase, so does the demand for reliable energy sources. Duke Energy is working to build a smarter, more reliable energy future by focusing our resources on efficient, renewable energy sources like the Bad Creek Project.
Even with the expansion of energy efficiency and demand reduction programs, cumulative annual energy consumption in the Carolinas is expected to grow by approximately 7,200 gigawatt-hours between 2021 and 2035.
In addition to growing demand, we plan to retire our coal generation stations in the Carolinas by 2030 and to triple our renewable energy generation sources. Expansion and accelerated development of the company’s storage portfolio is a necessary complement to the growth of generation from variable energy resources like solar and wind power. We are projecting the need for more than 13,000 megawatts (MW) of energy storage on the Duke Energy system by 2050.
The Bad Creek and Jocassee pumped-storage hydro facilities will continue to provide most of the energy storage on our system. These two stations provide approximately 2,200 MW of storage capacity. By the end of 2023, we will add an additional 335 MW at Bad Creek following the completion of a multiyear upgrade project. When upgrades are complete, the Bad Creek Project will be able to produce as much energy as some nuclear plants and power more than 1 million homes.
Duke Energy believes the Bad Creek II Power Complex represents a once-in-a-generation opportunity to double the project's renewable energy generation and storage capacity, with minimal long-term impacts to the natural environment.