Close on the heels of its recent upgrades of the GT26 and GT24 gas turbines for 50-Hertz and 60-Hertz power markets, Alstom in March launched its next-generation GT13E2 gas turbine, a medium-sized gas turbine of the 200-MW class (Figure 4).

4. The happy medium. Alstom in March launched its latest GT13E2 gas turbine upgrade. The medium-sized turbine of the 200-MW class has a 21-stage compressor with a variable inlet guide vane, an annular combustion system with closed-loop combustor cooling, and a five-stage turbine. Courtesy: Alstom

The E-class turbine first began operation two decades ago in 1993. It has already been upgraded twice: In 2002, which pushed performance from 166 MW at 35.7% gas turbine efficiency to 172 MW at 36.4%, and in 2005 to improve flame stability, lower NOx emissions, and increase performance to 185 MW and 37.8% gross efficiency. The newest upgrade boosts simple cycle performance to 202.7 MW at 38% gross efficiency as well as net combined cycle plant performance to 565 MW at 53.8% efficiency. Alstom boasts that the upgrade also has improved part-load efficiency and fast-start capability, promising more than 200 MW available in 15 minutes.

A general trend in the gas power sector shows that large generation plants need to be designed for the highest efficiency and operational flexibility to save fuel cost over a broad range of operating conditions and to match swiftly changing power demand. But Alstom says in a recent conference paper that another market segment exists outside of the one covered by combined cycle power plants based on large gas units. This will require “solutions based on smaller gas turbine units, sometimes in multi-unit configurations” to meet specific project requirements, adapt to plant configuration, and offer the highest reliability without compromising on performance and environmental issues. If “flexibility” is key for the large gas turbine market, “versatility” is what is required for the smaller turbine segment, it says.

The company cites International Energy Agency forecasts that natural gas generation will grow to 7,900 TWh in 2035 from 4,300 TWh in 2009. Nearly one-fifth of this growth is anticipated in China, another fifth in the Middle East, and a 10th in India. More than 60% of this growth will be produced by combined cycle gas turbines, but simple cycle gas turbines are also forecast to more than double.

Alstom expects the upgraded GT13E2 gas turbine will meet the needs of these countries as well as others, like Russia, which is boosting power capacity to meet growing demand spurred by economic growth and a mass of plant retirements. The French company has already been awarded eight GT13E2 units for projects in Russia. One reason is that nearly half of the installed gas power capacity in Russia is more than 30 years old, and a majority of that consists of inefficient gas-fired steam plants. Meanwhile, more than 60% of new capacity that will come online in Russia over the next decade will be gas-fired, but new turbines will still be required to meet the steam needs of existing combined heat and power systems, Alstom says.

—Sonal Patel is POWER’s senior writer.