TENNESSEE VALLEY AUTHORITY
Allen Combined Cycle Plant Now 75% Complete

The news from Memphis is promising: the new Allen project is going up on time and under budget and is contributing both renewable energy and economic benefit to Shelby County.

A cloudy day on the construction site at Allen Combined cycle plant belies Dan Tibbs' sunny attitude. He has much to be happy about. As General Manager, Major Projects for TVA, he's overseeing the Allen project and has just crossed a major milestone: 75% completion.

The Allen Combined Cycle Plant, which has been under construction since November of 2015, is no small undertaking; it's not simply a natural gas plant. "There are three aspects to the project," Tibbs explains. "Yes, we're building a two-on-one combined cycle natural gas plant to replace Allen Fossil Plant, which after having served Memphis well for 60 years is closing at the end of 2018."

But there are two other exciting aspects to the project. "We're also building a 1 MW solar farm at Allen, as well as a renewable biogas facility that will allow us to burn biogas, which is primarily made up of methane, in an auxiliary boiler to produce steam," he explains. "This biogas is a waste stream from the neighboring Maxson Wastewater Treatment Plant and would otherwise be incinerated, if not beneficially reused. The steam we produce will help power our steam turbine to produce about 5 MW of additional power." Together, the 6 MW of renewable energy will power approximately 3,000 homes and businesses, Tibbs estimates.

And yes, that is a big deal. "When we're done with the gas plant, it will be the most efficient in TVA's fleet, and among the most efficient in the world," he says. "We're using the latest technology from GE the 7HA.02 combustion turbine. We'll be able to produce over 1,000 MW at the site enough to serve about 600,000 homes and businesses."

Exceeding Expectations

All three parts of the project are proceeding nicely, according to Tibbs. In fact, the project slated for completion in June of 2018 is ahead of schedule and under budget. Moreover, the work has happened safely 1.7 million worker-hours have been logged to date with no lost-time incidents and only one recordable injury. But there's still plenty of work to come. "We'll continue at our peak workload over the next couple of months as we complete construction and begin commissioning and startup activities," Tibbs says.

"All of the equipment is on the site now," he notes. "We're in the process of finishing out our buildings, welding our piping systems, making all of our electrical connections and powering up our control systems. We will begin commissioning and starting up equipment later this summer, and we'll go into commercial operation when the plant has passed all of its reliability and performance testing, sometime early next year."

Another way the plant has exceeded expectations is in its economic contribution to the local economy. TVA estimates that it will spend approximately $240,000,000 directly in Shelby County by project's end, with a total economic impact in the region of approximately $1 billion.

"To date, we've spent about $56 million with Shelby County subcontractors, another $75 million on craft labor and another $60 million in city infrastructure to get both natural gas and biogas transported reliably to the plant," Tibbs says.

That's how Allen Combined Cycle Plant project TVA's mission trifecta of energy, environment and economic development with a renewable twist.

"We do have a lot to be proud of and are positioned well, but there is still a lot of work to be done with many risks still in front of us," Tibbs says, looking to the future. "We must continue to relentlessly focus on safety and project execution to finish as well as we have started."