The most powerful 60-Hz heavy-duty gas turbine available is this Model V84.3A, developed and tested by the Siemens Power Generation Group. It achieves an electrical output of 170 MW and a simple-cycle efficiency of 38 percent. Their high- performance figures were measured on the gas-turbine bed at the Siemens/KWU manufacturing plant in Berlin, Germany. It is anticipated that the new turbine will achieve at least a 58-percent combined-cycle efficiency. According to Siemens, one of the most important design features is the hybrid-burner-ring combustor with 24 hybrid burners. They enable dry low-NOx emissions control with both natural gas and fuel oil firing. Emissions lower than 25 ppm are anticipated when fired with natural gas. The photograph shows the rotor of the new gas turbine and part of the hybrid-burner-ring combustor.