Terror Lake Hydroelectric Generating Station facts for kids
The Terror Lake Hydroelectric Generating Station is a big power plant on Kodiak Island, Alaska. It's the main way Kodiak Island gets its electricity. This station uses the power of water to create energy, which is called Hydroelectricity.
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Terror Lake Power Plant: Powering Kodiak Island
The Terror Lake power plant has three special water turbines called Pelton runners. Each turbine can make about 11 megawatts of electricity. Two turbines were put in when the plant was built in 1985. A third, slightly more powerful turbine was added in 2013.
The power plant is owned and run by the Kodiak Electric Association, Inc.. This is a special kind of power company called an electrical cooperative, which means it's owned by the people who use its electricity. The station is about 25 miles from the city of Kodiak. You can only get there by flying or by boat.
How Terror Lake Makes Electricity
The main dam at Terror Lake is very long, about 2,100 feet, and 156 feet tall. It's a strong dam made of rocks and covered with concrete. Next to the dam is a spillway, which is like a big overflow area for water.
Terror Lake itself acts like a giant storage tank for water, called a reservoir. It covers an area of 850 acres and can hold a huge amount of water.
Water from the lake travels through a long tunnel, 10 feet wide and over 26,000 feet long! This tunnel leads to a large pipe called a penstock. The penstock is made of steel and is about 3,400 feet long. It gets wider as it goes, from 56 to 96 inches across. This pipe carries the water down to the power plant. After the water goes through the turbines, it flows out into the Kizhuyak River.
To collect even more water for the lake, there are other smaller dams, walls (called dikes), and channels built around the area.
Building the Power Plant
Building the Terror Lake power plant was a big job! A 17-mile private road was built from a special boat landing area to the power plant. Large equipment and materials arrived by landing craft (a type of boat) at the beach. Then, they were hauled up this private road.
Once the electricity is made, it travels through a 17-mile transmission line (power lines) at 138,000 volts. These lines connect the power plant to an electrical substation in the city of Kodiak. The State of Alaska first built this project in 1985, and it cost about $230,000,000.
Protecting Nature Around Terror Lake
The Terror Lake project is located inside the Kodiak National Wildlife Refuge. This means it's in a special area set aside to protect nature. Before the power plant was built, environmental studies were done. These studies checked to see how the project might affect the local wildlife, especially the famous Kodiak bear.
Powering Kodiak: What Gets Electricity?
The electricity from Terror Lake powers the city of Kodiak, Alaska and the areas around it. It also supplies power to the U.S. Coast Guard base and the nearby Kodiak Airport.
Before Terror Lake, Kodiak used diesel engine generators to make electricity. Now, these old diesel generators are mostly used only when a lot of extra power is needed, like during the busy fish canning season.
Green Energy for Kodiak
Kodiak Electric also uses other clean energy sources. They have six large wind turbines that make 1.5 megawatts of power each. Because Kodiak's power system is not connected to the main North American power grid, they also bought a 3-megawatt battery bank. This big battery helps keep the power steady when the demand for electricity changes suddenly or when the wind power shifts.
The Kodiak Electric cooperative has a goal to get 95% of their electricity from renewable sources by the year 2020. The low cost of power from Terror Lake has helped keep electricity prices stable for the city of Kodiak. This is because they don't have to burn as much expensive oil in the diesel generators anymore.
