The gas turbine marketplace will undergo significant changes in the decade between 2012 and 2021, according to Forecast International. The biggest gains will be in the maintenance, repair and overhaul (MRO) space where the current global total of $7.8 billion is expected to double within 10 years.
That still amounts to 12,521 gas turbine (GT) machines being produced for electrical power generation over the decade, having a value of production of more than $150 billion. GE remains the dollar value leader while Solar continues to produce the most turbines.
GTs are well suited to multiple roles in the global energy industry. Among these are serving as the motive force for large electrical generators, as well as the prime movers for pumps and compressors on pipelines. With natural gas emerging as the fuel of choice to bridge the way to a low-carbon energy future, gas turbines are ideally suited to be the foundation of the industry.
Advantages are flexibility, ease of operation, low emissions profiles, efficiency, and rapid deployment, to name a few. Combustion turbines are scalable to provide for industry’s needs, from small site applications to powering cities. Electricity, steam and compressed air can be supplied in varying combinations to meet the needs of various manufacturing processes or to provide district heating and cooling.
As opposed to the “person per megawatt” ratio that has been a rough guide for the staffing of large coal plants, GTs require a veritable skeleton crew; in stable operations two dozen operations and maintenance technicians can readily keep a 500 MW power plant operating in top condition. Small installations can go unmanned with telemetry from a remote location.
Most major manufacturers feature some shipping container-sized units in the 25 MW range that can be delivered, tied in to fuel and power lines, and operational in a matter of weeks. With combined cycle installations reaching the 60% mark for net plant efficiency ratings, gas turbine machines will continue to get significantly larger in terms of power output.
A gas turbine machine having a firing temperature of about 2,400°F (1,316°C) has about 56% net plant efficiency level in combined cycle configurations; at about 2,500°F (1,371°C), a 57.2 – 57.3% net plant efficiency; and at about 2,600°F (1,427°C), close to a 60% net plant efficiency.
Any technological advances above the 60% level will be small and incremental, and will take more time; but they will be introduced. What is left to accomplish with the gas turbine machine itself falls into the areas of improved combustion, more exotic heat resistant alloys, improved metallic- or ceramic-based blade and vane coatings, more advanced cooling schemes, improved steam and water injection techniques and increased use of fuel preheating. However, it should be noted that some advances can take their toll, actually placing GTs under greater stress, reducing the mean time between overhauls and the life of the machine.
(More in Turbomachinery Handbook 2013)