Lake Tillery Neighbors

What’s new: Federal license for the Yadkin-Pee Dee Hydro Project

In 2015, Duke Energy received a new license for the Yadkin-Pee Dee Hydro Project, which includes Lake Tillery and Blewett Falls Lake. This new license, issued by the Federal Energy Regulatory Commission (FERC), provides enhancements to water quality, recreation, fish and wildlife habitat protection, and land conservation while ensuring Duke Energy’s ability to meet customers’ needs with the production of clean, affordable and renewable hydropower.

Due to new FERC license requirements, lake levels at Lake Tillery are likely to fluctuate more than they have in the past. Requirements for minimum continuous water releases from both Tillery and Blewett Falls are higher than under the previous license. The license also requires new water releases to comply with state water quality standards and to support recreational needs in the connecting Pee Dee River reach.

Harnessing the clean energy of flowing water: How it works

Tillery Hydro, a four-unit conventional hydroelectric plant, was constructed on the Yadkin-Pee Dee River in the 1920s to provide electricity to customers in the Carolinas. The fourth and last unit was added in the 1960s. The plant features an impressive dam 2,800 feet long and 86 feet high that forms Lake Tillery, as well as 18 Tainter-style flood-management gates.

The plant produces 92 megawatts of clean, renewable energy for our customers and plays an important role on hot summer days and cold winter nights. Electricity produced by hydro plants, like Tillery, is available to meet peak customer demand within a few minutes and supports Duke Energy’s goal to achieve net-zero carbon emissions by 2050 by expanding its renewables portfolio of solar, wind and hydropower.

Conventional hydroelectric plants harness the energy produced by flowing water, using simple mechanics to convert the energy into electricity. Water falling from an elevated reservoir turns the turbine to generate electricity. Because it uses water as a fuel source, hydropower is inexpensive and environmentally friendly to produce. However, the amount of energy that can be generated is limited by the volume of water held by the dam in storage and is dependent upon rainfall for its energy source.

Common Hydropower Terms

Reservoir
The water is held in a reservoir or lake upstream from the dam.

Penstock
The penstock conveys the water from the lake into a chamber surrounding the turbine. The water in the lake is held at a higher elevation than the turbine so that it can fall with enough force to strike the turbine’s blades and cause it to spin.

Turbine and Generator
The turbine wheel is attached by a shaft to a system of magnets and wires called a generator. As the turbine rotates, these magnets and wires also spin – producing electricity in the surrounding stationary wires.

Draft Tube and Tailrace
The water returns to the river by passing through a draft tube under the turbine and into the tailrace.