The Tennessee Valley Authority recently completed a life-extension project that restored about 40 MW of generating capacity to its Pickwick Landing Dam project.
Pickwick Landing was the second dam built under the TVA Act of 1933. Construction on the six-unit, 240-MW station on the Tennessee River began in December 1934. In 1939, the price tag of the dam, its two original units and the required purchase of the flooded 63,700 acres totaled $31,841,230 — less than $600 million in 2020 dollars. The cost of Units 1 and 2 was $871,254 each, or about $18 million today. The final unit came online in 1952.
Beginning in 2015, TVA launched a life-extension project that involved four of these vintage machines. The challenge to repair Pickwick’s degraded turbines, which had trimmed an estimated 10 MW of generation capacity from each unit, was exacerbated by significant discovery of damaged components during disassembly. The outages required $123.5 million to complete.
Senior Project Manager Greg Barbee headed the overall Pickwick initiative, which took 61 months and totaled 644,840 combined workhours from TVA Generation Projects & Fleet Service crews and third-party vendors.
Although under budget by more than $2.8 million, the refurbishment cost of each unit was almost double their original Roosevelt-era sticker price.
“This project was challenging,” Barbee said. “But I know for all of us it’s rewarding to have been part of something that’s gonna benefit people for many years to come.”
The last of the four refurbished units — Unit 2 — was returned to service in August. The station is now able to achieve its original generating capacity of 240 MW, which is enough to power more than 140,000 homes. TVA estimates it will take less than eight years for the assets to pay for themselves.
Pickwick’s two remaining original units will begin life-extension outages in the next few years.
“TVA is committed to sustaining a healthy environment through low-carbon generation,” said Bob Deacy, senior vice president, TVA GP&FS. “To achieve our 2030 carbon-reduction goal and to meet the Valley’s demand for green power, we will continue to invest in hydro assets like those at Pickwick. Not only will these investments give businesses and corporations a competitive edge, but the outages we undergo today will create jobs tomorrow that will help many of the 10 million people we serve.”
Power producers across the U.S. are racing to find new solutions to meet the ever-growing demand for clean and renewable power, but TVA has a simpler solution: If they’re broke, fix ‘em. Hydroelectricity is one of the world’s oldest sources of green power and TVA has 109 of these conventional generating assets spinning inside the concrete petitions of 29 Valley dams.
TVA has performed at least 62 hydro unit outages since 1992, returning or adding an estimated 453 MWh of generation to a river fleet originally rated for 3,500 MWh. Today, TVA’s conventional hydro units have a capacity of 4,300 MW — enough to power more than 2.5 million homes.
Through these intensive restorations, TVA has extended the life of its generating assets and reached its 2020 carbon-reduction target — a 60% decrease from 2005 levels. Today, 54% of the TVA’s energy supply is from carbon-free sources. The agency expects to meet its 70% target by the end of 2030.