Morris Cogen, owned by Atlantic Power Corp, is a 177-MW combined-cycle facility with three GE Frame 6B gas turbine/generators and HRSGs, and a 60-MW steam turbine/generator, supplying a large ethylene manufacturing plant in Morris, Ill (near Chicago) with over 1-million lb/hr of steam and electricity since 1998. Excess power—about 120 MW—is sold into PJM. Morris pioneered the installation of two TurboPhase modules in 2014. The system was tested then and currently is shut down pending completion of control-system modifications and emissions testing. Final commissioning should be completed this year.
According to Joe Nichols, facility O&M manager, who updated owner/operators on the project at the Frame 6 Users Group annual meeting in Scottsdale, Ariz, June 22-28, said TurboPhase offers multiple benefits. Its greatest benefit, he continued, is likely the dollars that can be generated each month by responding more quickly (under a minute when the system is online) with additional incremental megawatts (7 MW) to satisfy PJM’s requirements in the performance-based frequency regulation market.
He explained that all resources wishing to supply regulation have to pass PJM’s multiple tests and are scored. Improving this “score” increases the amount of money a facility can make. Nichols believes TurboPhase will help Morris boost its score by several percentage points and improve its bid volume into the day-ahead market.
The gain comes because the gas turbine can respond much faster than the steam turbine and because the technique has almost zero parasitic penalty to the GT facility output (although it does involve its own source of fuel and the engine is a new point source that has to be permitted). Other benefits include reducing the operation of chillers for inlet-air cooling, the possibility of reducing steam-turbine load, and an incremental reduction in duct firing.
Nichols said Morris Cogen also is looking at other fast-response and storage options to continue to capitalize on new market opportunities. Because of interconnection issues, there is also a benefit to adding or subtracting incremental megawatts without having to open or close a breaker, or adding a new breaker, such as with a new unit.
One issue Nichols groused about was that the project team substantially under-estimated the budget for piping. Another: Integrating TurboPhase control systems with the gas-turbine Mark V control systems and plant DCS system to follow grid AGC signals proved more complex than originally thought.
It takes about seven minutes for the TurboPhase system to go through a startup cycle and enable fast-response dispatch. TurboPhase engineers say the system will start up in less than one minute once the bugs are eliminated and controls are optimized.
Nichols says TurboPhase plans to get the controls working for fast starts later this year, during final testing and commissioning. TurboPhase also plans to modify and tune the system for efficient part-load operation.
