Raccoon Mountain Pumped-Storage Plant

Raccoon Mountain Pumped-Storage Plant is a pumped-storage hydroelectric underground power station in Marion County, just west of Chattanooga in the U.S. state of Tennessee.

Raccoon Mountain Pumped-Storage Plant
Tailrace (TN River) of RMPS (TVA photo)
Raccoon Mountain Pumped-Storage Plant is located in Tennessee
Raccoon Mountain Pumped-Storage Plant
Location of Raccoon Mountain Pumped-Storage Plant in Tennessee
CountryUnited States
LocationMarion County, Tennessee
Coordinates35°2′54″N 85°23′48″W / 35.04833°N 85.39667°W / 35.04833; -85.39667
Construction beganJuly 1970 (1970-07)[1]
Opening date1978 (1978)
Construction cost$310 million (1978)[2][3]
Owner(s)Tennessee Valley Authority
Operator(s)Tennessee Valley Authority
Upper dam and spillways
Type of damEmbankment dam
Height (foundation)230 feet (70 m)[4]
Length8,500 feet (2,600 m)[4]
Dam volume10,000,000 cubic yards (7,600,000 m3)[1]
Upper reservoir
Total capacity107,000,000,000 US gallons (4.1×1011 L; 8.9×1010 imp gal)[4]
Surface area528 acres (214 ha)[4]
Maximum water depth222 feet (68 m)
Normal elevation1,672 feet (510 m)
Lower dam and spillways
Type of damGravity dam
ImpoundsTennessee River[5]
Height (foundation)81 feet (25 m)[5]
Length3,767 feet (1,148 m)[5]
Elevation at crest635.0 feet (193.5 m)
Spillway typeRadial gate
Lower reservoir
CreatesNickajack Lake[5]
Total capacity252,297 acre-feet (311,204,000 m3)
Active capacity32,132 acre-feet (39,634,000 m3)
Catchment area21,870 square miles (56,600 km2)
Surface area10,370 acres (4,200 ha)[5]
Maximum water depth145 feet (44 m)
Normal elevation633.5 feet (193.1 m)
Power Station
Operator(s)Tennessee Valley Authority
Commission date1978 (1978)
Hydraulic head1,040 feet (320 m)
Pump-generators4 × 413 MW
Installed capacity1652 MW
Capacity factor20%[6]
Storage capacity22 hours
2017 generation-686 GW·h
Raccoon Mountain

The facility is owned and operated by the Tennessee Valley Authority (TVA). Construction was started in 1970 and was completed in 1978.[7]

Water is pumped from Nickajack Lake on the Tennessee River at the base of Raccoon Mountain to a storage reservoir built at the top of the mountain. The reservoir at the top of the mountain covers 528 acres (214 ha), with a dam that is 230 feet (70 m) high and 5,800 feet (1,800 m) long, the largest rock-fill dam ever built by TVA. It takes 28 hours to fill the upper reservoir. During periods of high electric demand, water can be released from the reservoir through a tunnel drilled through the center of the mountain, driving electric generators in an underground hydroelectric plant.[7] The plant has a maximum power output of 1,652 megawatts (2,215,000 hp) and can generate for up to 22 hours. The plant is used most days and serves as an important element for peak power generation and grid balancing in the TVA system.[8][9]

The plant was idled in March 2012 due to cracks in the generators' rotors. The plant came entirely back on line in April 2014.[10]

Diagram of the facility
A Francis turbine

Recreation Edit

Raccoon Mountain is used for hiking, walking, running, road and mountain biking. It hosts a marathon, half marathon, double half marathon, relay, 5K and 10K race each year.[11]

References Edit

  1. ^ a b "TVA - The Mountaintop Marvel". www.tva.gov. Tennessee Valley Authority. Retrieved 3 April 2018.
  2. ^ "Repairs for Raccoon Mountain pumped-storage hydro facility pass $50 million". www.hydroworld.com. 30 November 2012. Retrieved 3 April 2018.
  3. ^ Poindexter, Gregory B. (26 May 2016). "TVA to begin geophysical testing at 1,652-MW Raccoon Mountain pumped-storage project". www.hydroworld.com. Retrieved 3 April 2018.
  4. ^ a b c d "TVA - Raccoon Mountain". www.tva.gov. Tennessee Valley Authority. Retrieved 3 April 2018.
  5. ^ a b c d e "TVA - The Great Replacement". www.tva.com. Tennessee Valley Authority. Retrieved 3 April 2018.
  6. ^ "Integrated Resource Plan: 2015 Draft Supplemental Environmental Impact Statement" (PDF). Tennessee Valley Authority. March 2015. Retrieved 3 April 2018.
  7. ^ a b TVA: Raccoon Mountain Pumped-Storage Plant
  8. ^ Adkins, F.E., 1987, TVA Report "Raccoon Mountain pumped storage plant; Ten years operating experience," IEEE Transactions on Energy Conversion, Volume EC-2, Issue 3 (September 1987), pages 361 - 368. CODEN:ITCNE
  9. ^ The Mountaintop Marvel, TVA Heritage website, accessed September 8, 2010
  10. ^ Sohn, Pam (August 10, 2012). "TVA's pumped storage facility on Raccoon Mountain idle". Chattanooga Times Free Press. Archived from the original on August 12, 2012. Retrieved August 26, 2012.
  11. ^ "Raccoon Mountain Marathon, Half Marathon, and Relay | Run Chattanooga". runchattanooga.org. Archived from the original on 2014-11-14.

External links Edit