On 9 March 2015, Siemens announced that it had achieved a generation efficiency record at the Cengiz Enerji Samsun combined-cycle gas turbine power plant in Turkey. With an installed capacity of 600 MWe, this plant achieves a net efficiency of almost 61%. This makes Cengiz Enerji Samsun the most efficient fossil-fired 50 Hz power plant in 2015, not only in Turkey, but in the world.
You can read more at the following link:
If you wonder how this level of generation efficiency compares to other types of electric power generators, then I recommend that you read the July 2003 report, “Efficiency in Electric Power Generation,” drafted by Union of the Electricity Industry – EURELECTRIC (Brussels, Belgium) and VGB PowerTech (Essen, Germany).
While this report is 12 years old, I think it remains one of the best single sources of comparative efficiency information on a very wide range of generator types. You can download a pdf version of this report by doing an Internet search for:
Efficiency in electricity generation – Eurelectric
The link you need should be at or near the top of your search results.
One of the key results presented in this report is a chart showing comparative efficiencies. The new Cengiz Enerji Samsun power plant raises the bar a few percentage points for “Large gas fired CCGT power plant”.
5 July 2016 update: New record for fossil plant efficiency
On 17 June 2016, General Electric (GE) and Électricité de France (EDF) began operating the first ever combined-cycle power plant equipped with GE’s 9HA large gas turbine. GE advertises the 9HA as the “world’s largest and most efficient heavy duty gas turbine”. There are two models, 9HA.01 and 9HA.02 that have claimed simple cycle outputs and net efficiencies of 397 MWe @ 41.5% net efficiency, and 510 MWe @ 41.8% net efficiency, respectively. In a combined cycle application, the power outputs and efficiencies increase substantially. GE claims the 9HA.01 delivers 592 MWe @ 61.6% net efficiency, while the 9HA.02 delivers 755 MWe @ 61.8% net efficiency. You can download a GE specification sheet on the 9HA at the following link:
With regard to the new 605 MWe combined cycle 9HA.01 power plant at Bouchain, France, GE announced that this plant has been recognized by Guinness World Records as the world’s most efficient combined-cycle power plant, with a demonstrated net efficiency of 62.22% (better than advertised by GE). You can read the GE announcement at the following link: