Moselle Repower Project

The Moselle Repower Project aimed to increase the capacity of the cycle by 150 percent, and decrease the heat rate by 40 percent

The 14th Annual Electric Power Conference & Exhibition took place recently at the Batlimore Convention Center, Batlimore, MD. This conference, programmed by the power industry in the U.S., covered strategic and technical issues and attracted more coal power producers than any other event. During the conference, a paper titled, ‘Repower of SMEPA Moselle Generating Station Units 1 & 2’ was presented by Ben Frerichs, a Mechanical Engineer at Burns & McDonnell. 

The presentation showcased the design, construction and performance of the Moselle Repower Project, located in Jones County, Mississippi, which is owned and operated by SMEPA. It comprises five units, and the gas fired boilers of units 1 and 2 have been abandoned to give way to combustion turbines and HRSGs. The design has been aimed at increasing the capacity and decreasing heat rate, while minimizing project costs and maximizing operational flexibility.

The repowered steam cycle is capable of producing HP Steam and LP Steam, and uses a GE Frame 7EA turbine and DLN-1 combustion system. Performance wise, while the existing plant has an output of 60 MW, a simple cycle is now capable of producing 85 MW with only 10,500 Btu/KWhr of LHV heat rate. A combined cycle effort with no duct firing gives a 125 MW output, and with maximum duct firing, it can go up to 150 MW, both with reduced gross LHV heat rates.

The project aimed to increase the capacity of the cycle by 150 percent, and decrease the heat rate by 40 percent, while minimizing the project costs by reusing existing assets. In the process, most of the steam cycle equipment and transmission and natural gas connections were reused. Maximum operational flexibility was achieved with operation being stabilized from 55 MW to 150 MW, and by using combustion gas and steam turbine bypass systems.