What the Ansaldo GT26 order means

Published on: 

The European Union (EU) blocked the takeover of Alstom until GE made arrangements to spin off the Alstom mature GT26 and the new GT36 single shaft gas turbine in its final stages of design. The EU was afraid of a GE monopoly for 50 Hz gas turbines. GE had no way out so elected to deal with the well established Italian gas turbine and power equipment company (since 1853) called Ansaldo Energia and also including PSM headquartered in Jupiter, Florida which is a full service and advanced design and technology provider to gas turbine power plants.

Ansaldo Energia is 40 % owned by Shanghigh Electric of China. A deal was struck but GE retained the rights for the 60 Hz GT24, but will probably abandon it. Immediately there were some skeptics that though that this company would not have the means to move forward with either unit. They were wrong.

(The new GT26 from Ansaldo Energia)

The parent company Ansaldo Energia of Italy formed a new subsidary company called Ansaldo Energia Switzerland (AES) to make and sell the GT26 and complete the design of the 50 Hz GT36, fully test it and then market it. The new GT36 was designed to compete directly with the latest 50 Hz gas turbines of GE, MHI and Siemens.

The new GT36 incorporates the PSM Florida designed FlameSheet sequential combustion system which has been well proven in the GT aftermarket for GE and W gas turbines.

Order for 8 GT 26 gas turbines

On March 11, 2016, Ansaldo Energia Switzerland announced in a news release that it had received two contracts for 8 new GT26 gas turbine generator sets and other equipment for combined cycle duty worth 600 million Euros split for two separate CCPP power plants, one for Ibri and the other for Sohar. The power will be fed to the Sultanate of Oman grid.

Juerg Schmidli, the Ansaldo Energia Switzerland new president, said this: “With its operating flexibility and high efficiency, the GT26 gas turbine will play a critical role in generating maximum project returns for our customer. This is the perfect start for our newly formed Company Ansaldo Energia Switzerland”.

Other news sources indicate that the supply chain for the GT26 parts will continue to remain the same as before coming from Germany, France and other places. The current Ansaldo Energia Switzerland version of the GT26 will be rated 345 MW ISO with an efficiency of 41% and in the CC mode 502 MW for 1x1 with an efficiency of 60.1 % ISO. This maximum efficiency is about one point lower than the competitor GTs, but the Reheat GT26 has a better part load CC efficiency and a better turn down with 15 % CC load during periods of low power demand. The GT26 also has great potential for uprating to the “J” class machines in the not too distant future and even a greater potential when the new CMC ceramic parts come into full use and production.


The reheat GT has more to gain than the simple cycle because of the dual combustion and duel cooling load requirements.

Importance of the GT26 order

The reheat GT26 with this new Ansaldo Energia Switzerland order indicates that this reheat concept will remain alive and will be available to all 50 Hz users, especially with potential for China. As a point of interest as to the success of the reheat (sequential combustion) GT24 and GT26 gas turbines there is a fleet of over 90 units with over 3.4 million fired hours and 44,000 starts located around the World generating Tesla/Westinghouse AC electric power. Therefore it is important to the World that this technology be preserved and expanded with the use of new machining technologies such as 3D printing and new hot gas parts made of the new CMC materials.

Progress with the new GT36

The new GT36 is reported to be on the test stand in Switzerland undergoing tests of all kinds. It is reported to have a new type combustion system developed by the PSM Florida subsidiary of Ansaldo Energia. It is a sequential burn design having two burns which makes it possible to have low NOX at reduced flame temperature outlets. Some details were given at a recent gas turbine European conference but full details will be forthcoming after the Switzerland tests have been completed.

ASME paper GT 2016-56696 presented at TurboExpo in Seoul, Korea details the design and rig validation.

In the near future a full review of the new GT36 will be made available by Ansaldo Energia Switzerland. It will be interesting to see just how it will compete with the other Big Three gas turbines.

(With inputs from Septimus Van der Linden)