Wiki: The 605 MW General Electric 9HA achieved a 62.22% efficiency rate with temperatures as high as 2,800 °F. For 2018, GE offers its 826 MW HA at over 64% efficiency in combined cycle due to advances in additive manufacturing and combustion breakthroughs, up from 63.7% in 2017 orders and on track to achieve 65% by the early 2020s.
HA gas turbine being assembled:
Additive manufacturing is playing a big role in these machines. From EENews:
The shiny metal tube in Kurt Goodwin's hand looks like a magician's work. A little smaller than a soda can, its thick walls are pierced by a series of holes seemingly drilled lengthwise, surrounding the center passageway. Except on second glance, the holes are uniformly curved. No drill could do that, confirms Goodwin, the leader of General Electric Co.'s $73 million advanced manufacturing center here in Greenville.
Goodwin is happy to show the piece off to a visitor, but no images, thank you. It is still proprietary.
GE made the tube with 3-D adaptive manufacturing, using a laser's intense heat to weld metal powder to form thin layers of solid metal, one atop the other, to create the complex design. It is part of the fuel assembly that delivers natural gas and massive volumes of air to burners on the business end of a GE natural gas turbine, the core product of the GE Power division..
...GE has invested $3 billion on the frontier technology of additive manufacturing, including $220 million in research and development as of last December.
As of December 2017, GE had shipped 25,000 3-D parts for its jet engines and power units.