Advanced Technologies for Gas Turbines (2020)
Chapter: Summary
Summary
This report identifies high-priority opportunities for improving and creating advanced technologies that can be introduced into the design and manufacture of gas turbines to substantially accelerate improvements to performance (e.g., efficiency and life-cycle cost). The report also describes the state of development that could be achieved by 2030. Three gas turbine applications are considered:
- Power generation (i.e., large, ground-based gas turbines that generate electricity to power the electrical grid);
- Aviation (i.e., commercial and military aircraft propulsion); and
- Oil and gas industry.1
In order to identify specific research goals, research areas, and research topics of particular importance, the committee
- Assessed the 2030 gas turbine global landscape via analysis of global leadership, market trends, and technology trends that impact the gas turbine applications above.
- Developed a prioritization process.
- Defined high-priority research goals for each of the three gas turbine applications of interest.
- Identified high-priority research areas of greatest relevance to achieving the specified goals.
- Identified high-priority research topics for each research area to provide more specific guidance on the recommended research.
GAS TURBINE GLOBAL VIEW
Leadership in gas turbine technologies is of continuing importance for the United States in general and the Department of Energy (DOE) in particular, as the value of gas turbine production is projected to grow substantially by 2030 and beyond. The major global market trends important to the future of gas turbine technologies include changes in (1) world demographics, (2) energy security and resilience, (3) decarbonization, and (4) customer profiles. The major global technology trends that define the technological environment in which gas turbine
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1 The committee determined that within the oil and gas industry, the highest-priority research should focus on gas turbines that power natural gas compressors in pipeline applications.
research and development will take place are (1) inexpensive, large-scale computational capabilities; (2) highly autonomous systems; (3) additive manufacturing; (4) artificial intelligence; and (5) cybersecurity.
Globally, electricity generation has more than doubled since 1990,2 and it could grow by more than 50 percent over the next two decades.3 In the United States, gas turbine facilities powered by natural gas generate about one-third of the electrical power used by the electrical grid.4 Both the total amount of electrical power generated by natural gas and the percentage of the U.S. demand for electrical power that is met by natural gas are projected to increase through at least 2050.5
The global demand for oil and gas could increase by 20 percent over the next 20 years, with China accounting for one-third of the growth.6 However, this growth is expected to plateau after 20357 or see a contraction, depending on energy policies regarding emissions and the use of renewable energy that are implemented internationally because of concerns about climate change, air quality, and overall sustainability.8 Research and development (R&D) to substantially reduce carbon dioxide (CO2) emissions may mitigate concerns with respect to climate change. Even so, demand for natural gas could contract if utility-scale energy storage technologies enable solar and wind-generated power to meet demand-driven requirements.
In aviation, essentially all large commercial and military airplanes are powered by gas turbine propulsion systems. During the 20 years ending in 2017, the number of commercial airline passengers globally almost tripled,9 and over the next 20 years it is projected that more than 40,000 new aircraft will be produced.
Given the above trends, the gas turbine industry will continue to play a critically important role in the generation of electric power, aircraft propulsion, and the oil and gas industry for decades to come, both domestically and globally. The operating efficiency, power density, reliability, and safety of gas turbines are well established. In one potential scenario, excess solar or wind power could be used to create hydrogen as an important energy storage mechanism, which in turn could be burned in gas turbines to create electricity. Gas turbines are powering the oil and gas industry all along the value chain. The aviation market shows a strong preference for gas turbines given their proven efficiency, power density, reliability, and safety. Gas turbines will therefore likely continue to dominate the growing aviation market for the foreseeable future. Altogether, the projected yearly global value of production of gas turbines is projected to grow from about $90 billion today to $110 billion by 2032, with aviation gas turbines accounting for about 85 percent of the total market.10
PRIORITIZATION PROCESS
With the above global view in mind, the committee fashioned a multistep prioritization process to identify high-priority research goals, areas, and topics for gas turbines for each of the three applications. First, it agreed upon three selection criteria relevant to the goals: (1) performance improvement, (2) technical risk, and (3) breadth of application.
The performance improvement selection criterion was used to assess the extent to which the accomplishment of a goal could have the potential to improve the performance of gas turbines for each application. As will be discussed in more detail below, performance parameters of particular interest are as follows:
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2 International Energy Agency, 2019, Electricity Information: Overview (2019 Edition), http://bit.ly/2JRQ9u3.
3 International Energy Agency, 2018, World Energy Outlook 2018,https://www.iea.org/weo2018.
4 Energy Information Administration, Electricity Power Monthly with Data for July 2019, Table 1.1, “Net Generation by Energy Source: Total (All Sectors), 2009–August 2019,” http://bit.ly/2oOKXj6.
5 Energy Information Administration, 2019, Annual Energy Outlook 2019 with Projections to 2050, p. 21, https://www.eia.gov/outlooks/archive/aeo19.
6 International Energy Agency, 2019, Electricity Information: Overview (2019 Edition), http://bit.ly/2JRQ9u3.
7 McKinsey and Company, 2019, Global Energy Perspective 2019: Reference Case (Summary), https://mck.co/2NH3yGg, January.
8 Renewable sources of energy include solar power, wind power, hydroelectric power, energy storage systems that store renewable energy when generating capacity exceeds demand, and gas turbines that are powered by renewable fuels. Renewable fuels include hydrogen, ammonia, biofuels, and synthetic gaseous or liquid hydrocarbons that are generated by electricity from renewable sources of energy.
9 The World Bank, 2019, “Air Transport, Passengers Carried,” https://data.worldbank.org/indicator/IS.AIR.PSGR?end=2017&start=1970&view=chart, accessed November 5, 2019.
10 L. Langston, 2018, Anticipated but unwelcome, Mechanical Engineering 140:36-41, doi: 10.1115/1.2018-JUN-2, http://bit.ly/32iMzzi.
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Efficiency
- Full rated load
- Partial load (across the operating envelope)
- Life-cycle cost
- Design and development time and cost
- Manufacturing time and cost
- Reliability, availability, and maintainability (RAM)
- Fuel flexibility
- CO2 emissions
- Compatibility with renewable energy sources and the future electrical grid (for power generation and oil and gas applications only)
The technical risk selection criterion was used to assess the extent to which a goal faces an appropriate level of technical risk. Goals are expected to be aggressive in that efforts to achieve the goal will face medium-to-high risk and may fall short. The high-priority goals do not include low-risk activities given the expectation that low-risk research that could substantially accelerate improvements to the performance of gas turbines would have already been addressed by government, industry, or academic members of the gas turbine community. However, the goals should not be overly aggressive to the extent that there is little or no prospect that substantial progress in achieving the goal will be accomplished between now and 2030.
The breadth of application selection criterion was used to assess the extent to which accomplishment of a goal could support the accomplishment of other goals, and the extent to which a goal is related to multiple research areas and topics. Given the context of the global view, the prioritization process establishes the following high-priority goals for the three applications.11
RECOMMENDATION: High-Priority Goals. In order to expedite the process of improving and creating advanced technologies that can be introduced into the design and manufacture of gas turbines, the Department of Energy, other government agencies, industry, and academia should pursue the following goals as a high priority:
Power Generation Gas Turbine Goals
- Efficiency. Increase combined cycle efficiency to 70 percent and simple cycle efficiency to more than 50 percent.
- Compatibility with Renewable Energy Sources. Reduce turbine start-up times and improve the ability of gas turbines operating in simple and combined cycles to operate at high efficiency while accommodating flexible power demands and other requirements associated with integrating power generation turbines with renewable energy sources and energy storage systems.
- CO2 Emissions. Reduce CO2 emissions to as close to zero as possible while still meeting emission standards for oxides of nitrogen (NOx).
- Fuel Flexibility. Enable gas turbines for power generation to operate with natural gas fuel mixtures with high proportions (up to 100 percent) of hydrogen and other renewable gas fuels of various compositions.
- Levelized Cost of Electricity. Enable reductions in the levelized cost of electricity from power generation gas turbines to ensure that these costs remain competitive with the cost of solar and wind power systems over the long term.
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11 Each application area has a different number of goals: power generation has five, aviation has one, and oil and gas has three. Neither the distribution of the goals among the three application areas nor the ordering of the goals for a particular application is indicative of (1) the relative importance of one application area versus another or one goal versus another, or (2) how resources should be allocated among research related to different applications and goals. Rather, for example, the committee concluded that there are five key goals of comparable importance that are applicable to power generation gas turbines, whereas there is one overriding goal that pertains to aviation gas turbines. Within the power generation and oil and gas application areas, the ordering of the goals was selected to facilitate the explanation of each goal because in some cases the details associated with one goal provide a foundation for understanding other goals. The various research areas were likewise ordered to facilitate understanding and do not indicate relative priority.
Aviation Gas Turbine Goal
- Fuel Burn. Develop advanced technologies that will increase thermal efficiency to enable a 25 percent reduction in fuel burn relative to today’s best-in-class turbofan engines for narrow- and wide-body aircraft, and concomitant reductions in fuel burn for military aircraft.
Oil and Gas Industry Gas Turbine Goals
- Fuel Flexibility. Enable gas turbines for natural gas pipeline compressor stations (and other oil and gas applications) to operate with natural gas fuel mixtures with high proportions (up to 100 percent) of hydrogen and other renewable gas fuels of various compositions.
- Condition-Based Operations and Maintenance. Develop the ability for condition-based operations and maintenance to increase periods of uninterrupted operation for natural gas pipeline compressor stations to 3 years or more without reducing availability or reliability.
- Flexible Power Demand and Efficiency. Design gas turbines for pipeline compressor stations (and other oil and gas applications) that can handle large load swings and operate at partial load with efficiency that exceeds the efficiency of stations that use compressors driven by electric motors.
The committee then used a slightly modified set of selection criteria (benefit, technical risk, and breadth of application) to identify 10 high-priority research areas. The first five research areas focus on disciplines; the remaining five focus on systems.
RECOMMENDATION: High-Priority Research Areas. In order to expedite the process of improving and creating advanced technologies that can be introduced into the design and manufacture of gas turbines, the Department of Energy, other government agencies, industry, and academia should pursue the following research areas as a high priority:
- Combustion. Enhance foundational knowledge needed for low-emission combustion systems that (1) can work in high-pressure, high-temperature environments that will be required for high-efficiency cycles, including constant pressure and pressure gain combustion systems; and (2) have operational characteristics that do not limit the gas turbine’s transient response or turndown (i.e., ability to operate acceptably over a range of power settings), with acceptable performance over a range of fuel compositions.
- Structural Materials and Coatings. Develop (1) the technology required to produce ceramic matrix composites; (2) advanced computational models; and (3) advanced metallic material and component technologies that would improve the efficiency of gas turbines and reduce their development time and life-cycle costs.
- Additive Manufacturing for Gas Turbines. Integrate model-based definitions of gas turbine materials (those already in use as well as advanced materials under development), materials processes, and manufacturing machines with design tools and shop floor equipment to accelerate design and increase component yield while reducing performance variability.
- Thermal Management. Develop advanced cooling strategies that can quickly and inexpensively be incorporated into gas turbines and enable higher turbine inlet temperatures, increased cycle pressure ratios, and lower combustor and turbine cooling flows, thereby yielding increased thermodynamic cycle efficiency while meeting gas turbine life requirements.
- High-Fidelity Integrated Simulations and Validation Experiments. Develop and validate physics-based, high-fidelity computational predictive simulations that enable detailed engineering analysis early in the design process, including virtual exploration of gas turbine module interactions and off-design operating conditions.
- Unconventional Thermodynamic Cycles. Investigate and develop unconventional thermodynamic cycles for simple and combined cycle gas turbines to improve thermal efficiency, while ensuring that trade-offs with other elements of gas turbine performance, such as life-cycle cost, are acceptable.
- System Integration. Improve, modify, and/or expand the conventional gas turbine architecture (i.e., a compressor module, combustor module, and turbine module on a common shaft in the direction of gas flow) to enable the development of gas turbines with higher performance and/or greater breadth of application.
- Condition-Based Operations and Maintenance. Develop technologies that will improve operation of gas turbines by reducing the amount of scheduled and unscheduled maintenance, thereby reducing unscheduled shutdowns.
- Digital Twins and Their Supporting Infrastructure. Develop the capability to generate enhanced digital twins and a digital thread infrastructure that supports them.
- Gas Turbines in Pipeline Applications. Investigate (1) opportunities to improve the efficiency of gas turbines in pipeline applications exposed to extended periods of partial load operation and (2) the safety implications of gas turbines with a substantial percentage of hydrogen in the fuel.
