Combustion Testing Begins at Paradise CC Plant

3-2-1-ignition! Paradise Combined Cycle Unit 1 fired up for the first time at 5:23 p.m. EST Monday. All three gas-fired units will go through a series of tests over the next few months in preparation for commercial operation in 2017.

OCTOBER 14, 2016—Paradise Combined Cycle Unit 1 fired up for the first time at 5:23 pm EST Monday, Oct. 10. This is a major milestone in the completion of the plant near Drakesboro, Kentucky.

gas plant

What does that mean? “We admitted natural gas fuel into the combustion turbine, established ignition and brought the turbine up to operating speed,” explains Roger Waldrep, general manager, TVA Major Projects. “That tells us whether the combustion system works, vibration is good, etc.—it’s kind of like cranking your car to check the health of the engine.”

No electricity was generated on day one of what will be a 19-day testing process, he explains. “We’ll just be generating heat and doing our pre-operation checks.” This will also satisfy the GE requirement to have a several hour heat run to condition the new rotors.

Day two of the testing is when the real action happens: “We’ll refire the engine, bring it up to normal operating speed, and match frequency and voltage to the TVA grid,” Waldrep says. “Then we’ll close the breaker and connect to the grid, which is initial synchronization. That’s the first time we’ll be generating power, and that power will be available on the grid. That’s a big day.”

On day three, “we’ll again synchronize the unit to the grid and incrementally increase power until we get to full load.”

At that point, the unit operators and tuning engineers will be ready to fluctuate the loads over the next few days. Waldrep likens the process to the ascension testing that happened in the start-up phase of Watts Bar Nuclear Plant’s Unit 2. “We will go to low loads and make sure our control systems and voltage regulators are working,” Waldrep says. “Then we’ll move the load around, going up to 200-225 megawatts and coming back down, focusing on testing, control and tuning in the subsequent days.”

Unit 2 and Unit 3 will be tested first sequentially and then concurrently with Unit 1.

Once the testing of the combustion turbine units is complete, Paradise will face another round of testing—this time including all of the steam systems. “We’ll spend another three weeks refiring the gas turbines to make steam that we’ll blow through the boilers and steam piping systems,” Waldrep says. “That way we’ll ensure that the steam system is sound and that all the piping systems are free of any debris.” This period is referred to as “steam blows”.

Waldrep expects that this initial testing and steam system restoration should be complete by January or February of 2017. Then the plant will undergo full load testing with all three combustion turbines and the steam turbine-generator in operation, as well as completion of all contractual performance and reliability acceptance tests. The goal is for Paradise Combined Cycle Plant, which will be able to produce 1,100 MW at full capacity—enough energy to power about 640,000 homes and businesses. It's expected to be in commercial power production in time to help meet the peek demands of 2017.

TVA's investment in Paradise Combined Cycle Plant underscores its movement toward a more balanced portfolio. The gas units at Paradise will offer the flexibility to adjust generation quickly while reducing carbon output by 50 percent as compared to a coal plant.