• Real-time testing and validation of HL class technologies at a customer site
  • Progressive integration of new technologies into the existing gas turbine portfolio
  • Easy integration into Siemens’ digital offering – interface with MindSphere

With the development of the HL class, Siemens is taking a new technological step towards improving the efficiency of power plants. In June 2017, the company announced that it wanted to validate its HL-class technologies at the site of a Duke Energy power plant in Lincoln County, North Carolina. Completely innovative, this class of high performance turbines is derived from Siemens’ proven H class. Result: a technology that gives access to a level of efficiency and unprecedented power. The class HL thus opens the way to yields higher than 63%,

By incorporating these key new technologies into its gas turbine portfolio, Siemens is also accelerating the pace of technology upgrades and improved competitiveness. In the near future, all of its customers will benefit from further increases in efficiency and power. This approach is part of efforts to help customers stay competitive in a rapidly changing market. For example, Siemens is committed to significantly reducing manufacturing and delivery times by focusing on standardization and modularization.


The new Siemens HL class consists of three turbines: the SGT5-9000HL, the SGT6- 9000HL and the SGT5-8000HL. In the single cycle, the gas turbine SGT-9000HL provides 545 MW in 50 Hz and 374 MW in 60 Hz. The SGT5-8000HL delivers 453 MW in single cycle. In the combined cycle, the three turbines achieve a yield greater than 63%.

To achieve these high efficiency levels, the turbines must operate at extremely high combustion temperatures. Siemens experts have therefore developed state-of-the-art combustion technologies, innovative multilayer coatings, high-efficiency cooling systems for guide vanes and moving vanes, and an optimized water-steam circuit. Optimized seals also minimize cooling consumption and cooling losses. Improved 3D blades also ensure better aerodynamic efficiency of the compressor. Pre-defined and pre-assembled components as well as pre-selected suppliers considerably reduce project completion and start-up times. The turbines are designed to easily integrate with Siemens ‘digital offerings for power plant operators and power suppliers, and interface with MindSphere, Siemens’ cloud-based IoT operating system. MindSphere provides access to the powerful analytics tools from Siemens and its partners that allow our customers direct access to their turbine operating data and assist them in their decision making.

“Driven by digitalisation, the pace of technological development is accelerating in the field of power generation,” said Willi Meixner, CEO of Siemens Power and Gas Division. “It took us ten years, from 2000 to 2010, to increase the performance of our combined cycle plants by 58 to 60%, and six more years to reach 61.5% in 2016. With 63% and beyond, we are crossing a new course today. It’s extraordinary. But we know that speed and performance are not everything. For our customers, the reliability and cost-effectiveness of our solutions are equally important, as are partnerships, financing assistance and insurability. “

To minimize the risks to the customer, Siemens has adopted a very elaborate overall approach. After having tested the various components and prototypes in-house, Siemens continues today the testing and validation in real conditions on the site of a world leader in the production of energy. “With the new HL class, our customers will be ready to face all future developments in digitalization,” Willi Meixner added.