David J. Franus
Not too long ago, America woke up and realized that it was running out of electric power. With a growth in the population, a multi-fold increase in electrical power-hungry electronics, and a long cycle of hot summers and warm winters, demands on the providers of electric power have grown almost astronomically. The providers of electrical power had long believed that if we all practiced energy economy, they would not have to add new capacity in the form of power plants.
Well, time has told the tale: energy shortages in California have forced blackouts at the worst, and brownouts/rolling outages at the best; environmentalists and other unenlightened citizens have campaigned against new nuclear power plant construction and upgrading/uprating of the current 100+ current plants; power is being procured (when available) from sources farther and farther away; and the conventional and seemingly always reliable hydroelectric-generated power is not too effective if there is a meager snowfall total in the winter. The overall power need now spreads the entire gamut of generation, from baseload to peaking to standby.
When the need becomes critical, new electrical power generation capacity can come from several sources: fossil-fuel-burning machines, such as gas turbine machines (including microturbine and miniturbine machines of under 200 kW) and diesels; hydroelectric; nuclear; solar; wind; from conventional power plants that burn coal, food waste and bagasse; and from other much more exotic means such as geothermal, ocean currents, and fuel cells.
Fuels cells, despite their immense appeal by virtually eliminating harmful emissions, are still considered to be in the demonstration stage; wind power, while commercially available, is not available everywhere, its overall efficiency is about 50 percent, and it is expensive in the near term on a dollar-per-kilowatt-hour basis; nuclear power plants and hydroelectric plants are very expensive and require a very long period of hearings, financing, approvals, and construction; solar power is very appealing, but it’s somewhat akin to wind power-it is not available everywhere, and it too is expensive on a dollar-per-kilowatt-hour basis.
Well, not too much. Of that which is left, we should address gas turbine machines, and microturbines, with emphasis on the 200 kW+ gas turbine machines that are utilized in simple-cycle and combined-cycle power generation, to include combined heat and power (CHP), also known as cogeneration, applications. Above the level of microturbines and miniturbines whose efficiencies range about 20-28 percent, that which we consider to be true gas turbine machines range in power output from about 200 kW to the super-high-power machines of 250-350 MW. (For reference here, “gas turbine machine,” will include only those with power output of 200 kW and greater.) Today, gas turbine machines have simple-cycle efficiencies of at least 30 percent and some are approaching 44 percent in simple-cycle, and approaching 60 percent in combined-cycle.
Production of gas turbine machines above 200 kW for electrical power generation has followed a sine-wave pattern in the recent past: a ramp up to a then-high in 1996, a slight drop in 1997, more of a drop in 1998, and then hefty growth in 1999 and 2000. We estimate that gas turbine machine production in 1998 was just over 750 machines; production in 2000 is estimated at just over 1,200 machines. Looking just at North America, production of gas turbine machines ranged from a very pitiful 20 or so machines in 1996 to about 600 machines in 2000. We see total production raising to about 1,750 machines in 2005, and then dipping, and then rebounding to just over 1,800 machines in 2010, and then dropping for a while until the new capacity/capacity increase sine-wave pattern takes effect. The sine wave to come should be somewhat stretched out in comparison to the previous wave.
What’s in the future?
While gas turbine machines continue to be ordered and fabricated for electrical power generation by their normally intended end-use type of service-continuous duty, standby duty, and peaking duty-the lower-powered gas turbine machines, those up to about 3.5-4 MW, have traditionally been employed in standby duty. As we move up the power spectrum, the normal-use shift toward continuous duty becomes more noticeable at the power level of 20-30 MW. At the power level of about 120-125 MW and larger, virtually all gas turbine machines ordered are intended for continuous generation duty. That trend seems almost inviolate, and we expect it to continue for the near term.
Given the urgent need for new baseload capacity as well as for current power plant capacity additions, Forecast International feels that the worldwide demand for the latest-technology, high-technology gas turbine-based power plants will result in the increased production of the super-large gas turbine machines, those of 180 MW and larger. Production of those machines could grow from over 100 machines in 2001 to over 275-325 machines per year in the 2004-2006 period. Several regions and countries are likely to be the main procurers of these mega-machines, including China, North Korea, and the Middle East, and the Mercosur nations.
With combined-cycle installations approaching and just about touching 60 percent, we do not believe that gas turbine machines will continue to get larger and larger in terms of power output. With a gas turbine machine having a firing temperature of about 2400°F (1316°C), we were at about a 56-percent level in net plant efficiency in combined-cycle configurations; at about 2500°F (1316°C), we were at about a 57.2-57.3-percent net plant efficiency; and at about 2600°F (1427°C), we were very close to a 60-percent net plant efficiency. Any technological advances above that 60-percent level will be small, and incremental, and will take more time to be introduced-but they will be introduced. What is “left” to do or accomplish with the gas turbine machine itself, we feel, falls into the areas of yet-improved combustion, more exotic heat-resistant alloys, improved metallic- or ceramic-based blade and vane coatings, more sophisticated cooling schemes, improved steam/water injection techniques, and increased use of fuel preheating. It should be noted here that some advances, however, could take their toll on the gas turbine machines, actually placing the machines under greater and greater stress.
A great concern with the newer technology machines is that of early and often well-publicized failures that can and have caused the original equipment manufacturers (OEMs) to “suffer” in terms of cost, delays, and reputation-creating an atmosphere of intense scrutiny when the OEMs come out with another new product or product improvement.
Here is a gas turbine industry facet that we feel will likely gain momentum: When an electric utility has an urgent requirement for new peaking capacity, utilizing gas turbine machines fabricated for other projects could be a viable option since using a “used” machine could dramatically shorten a project’s development schedule. An example of this scenario is when a (state of) Georgia power plant needed gas turbine generators for operation in the summer of 2000, it bought three 50 Hz machines that were operating in a power plant in Argentina. GE Aeroderivative and Package Services converted the three machines from 50 Hz to 60 Hz operation. Another example is Colorado Springs Utilities which, in order to get around the increasingly lengthening period of time from order to erection of new gas turbine machines, acquired two new GE Power Generation Frame 6B machines that had been in storage for about six years.
What’s going to happen?
The number of primary players in the gas turbine industry will continue to be reshuffled, and likely be reduced. Streamlining of the number of firms has already taken place: Siemens acquired the Westinghouse gas turbine line, AlliedSignal took over Honeywell but has kept the Honeywell name (the Vericor Power Systems joint venture with MTU has assumed the turbine machine-building responsibilities), Alstom has bought out the ABB Alstom entity, GE has absorbed the Stewart & Stevenson and Nuovo Pignone packaging operations all the while disassociating itself from Dresser-Rand, and Rolls-Royce acquired (not too easily) Allison. Among the major or near-major gas turbine manufacturers that are still “out there” are Pratt & Whitney Power Systems (PWPS) and Fiat Avio.
Who knows, maybe one or both of these entities is being eyed as an acquisition.
David J. Franus is senior analyst for power systems for Forecast International/DMS Inc., a Newtown, Conn.-based firm who specialize in market analysis for aerospace, defense, power systems and military electronics. He can be contacted via e-mail at dave.franus @forecast1.com.