Electrification Will Enable Sustained Prosperity
By Henry R. Linden, Illinois Institute of Technology Gas Research Institute founding president and executive advisor
I want to address this topic from the perspective of a technological optimist who believes by 2100 the global energy system will have achieved sustainability or, at least, closely approached it. What will drive this evolution to resource and environmental sustainability is not depletion of economically recoverable fossil fuels or the current anxiety over anthropogenic climate change. Instead, it will be an avalanche of new cost-effective and environmentally benign energy supply, transport, storage and end-use technologies that will change the global energy system even more dramatically than the technological advances of the past 100 years.
The key elements of this transfor-mation will be the electrification of most stationary energy uses and the gradual replacement of petroleum-based transportation fuels with hydrogen from non-fossil sources. Hydrogen will also become an important energy storage and trans-port medium thanks to the ready convertibility of electricity from intermittent sources to hydrogen by water electrolysis and of hydrogen back to electricity via fuel cells. This may be a surprising vision for someone so closely identified with the gas industry for the past 50 years, especially since respected geologists now project 20,000 trillion cubic feet of remaining recoverable natural gas resources, four times the proved global reserves, or 250 years of current consumption. The corresponding figures for crude oil are 3,000 billion barrels, three times the proved global reserves, or 125 years of current consumption. These huge gas reserves and resources should allow natural gas to retain a major share of the energy market over the next century. However, even abundant and clean-burning natural gas does not meet the test of sustainability. It still emits greenhouse gases and is exhaustible unless the dreams of those who still believe in its largely abiogenic (i.gif., cosmic) origin come true. Nevertheless, natural gas seems destined to become the preferred fuel for new central and distributed generating capacity well into the 21st century. This will be the case even in areas without indigenous natural gas resources, such as the inner Pacific Rim, which is increasingly fueled with liquefied natural gas.
One reason for this convergence of the gas and electric business is aeroderivative turbine technologies and ample and cheap gas supplies have reduced the marginal cost of baseload power to 3 cents/kWh or less. The installed cost of
combined-cycle systems in the 250 MW capacity range has dropped to $350/kW and all-in costs have dropped to about $450/kW, while
efficiencies have risen to 60 percent (lower heating value basis) and heat rates have declined to 6,300 Btu/kWh (higher heating value basis). Further efficiency gains are expected. The all-in cost of simple combustion turbine systems in the 150 MW capacity range is down to $300/kW and efficiencies are in the vicinity of 40 percent. As these cost reductions and performance improvements are extended to smaller and smaller combustion turbines, the economic and opera-tional advantages of gas-fired distributed over central generation will become self-evident, especially in a cogenerator configuration. There are ample assembled commercial and industrial heat loads to utilize the recoverable thermal energy from turbines with capacities of 3 to 10 MW and up to 40 MW as they displace central generation. Supple-mental firing of the heat recovery boiler can further reduce the net cost of power in many applications.
Thus, I am confident, as the electric industry restructures into separate wires, generating and energy service businesses, gas-fired distributed generation will play an ever more important role and facilitate the eventual introduction of high-tech renewable power sources. But, for many decades, molecules-to-electrons technologies will dominate. A good example is the now fully commercialized International Fuel Cells Corp./ONSI PC-25 200 kW natural gas fuel cell system which employs a phosphoric acid electrolyte, operates at 400 F, has a 36 percent electric efficiency and an 82 percent overall efficiency as a cogenerator. Even at today`s subsidized installed cost of $3,000/kW (i.gif., after deducting the $1,000/kW Department of Energy credit), it is cost-competitive with purchased power in such high load factor applications as hospitals, where the waste heat in the form of hot water can be used effectively for laundry operations. The new low-temperature proton exchange membrane (PEM) fuel cell systems which have higher electric conversion efficiencies and power densities also show great promise for distributed generation using reformed natural gas in applications in the hundreds of kilowatt to 1-2 MW range. Hydrogen or methanol powered PEM fuel cell systems have already become the technology of choice for electro-motive surface transport.
Although I believe gas-fueled distributed generation should be the key element of a least-cost energy service strategy over the next 25 to 50 years, the transition to a sustainable energy system-i.gif., a system solely dependent on renewable or inexhaustible primary energy sources-also requires a reliable baseload supply component. It is not possible at this time to place total or even primary reliance on renewable technologies to meet the energy needs of a global population likely to reach 11 billion by 2100. This is why most of the industrialized world has recognized the breeder reactor as an essential building block in achieving sustainability. As noted before, photovoltaic, solar thermal and wind energy are inherently intermittent sources of power and would require costly investments in storage without a back-up baseload supply. The prospects for biomass as a primary energy supply are also ill-defined because of constraints on land use by food production requirements, large parasitic energy and materials requirements for planting, fertilizing, harvesting and conversion, and the inefficiency of
photosynthetic conversion of solar energy to electricity compared to, say, photovoltaics. Therefore, the loss of confidence in the nuclear option and the recent U.S. abandonment of breeder reactor development have been detrimental to the creation of a technology base for a sustainable energy system. The integral fast reactor option appears to offer the most promising technical, economic and socio-political solution. It simplifies fuel reprocessing and minimizes proliferation risks and radioactive waste disposal problems.
The future of surface transportation is also linked to power supply issues since it now seems quite clear electromotive technologies offer the most promising route to sustainability and cost-effective efficiency gains. Rechargeable batteries will probably only be able to capture niche markets because of inherent performance limitations. Hybrid turbine or engine systems powered with hydrocarbon fuels are obviously not sustainable although, based on the latest estimates of remaining recoverable resources, oil production should peak well after 2025 and gas much later than that.
They also emit pollutants and greenhouse gases, albeit at greatly reduced levels. Production of methanol or hydrogen from natural gas and eventually coal also fails the test of sustainability because even coal is nominally exhaustible and a lot of carbon dioxide is generated. In spite of the questionable evidence for detrimental anthropogenic climate change, this issue would certainly be raised. This leaves non-fossil hydrogen as the most logical option for powering fuel cell or hybrid fuel cell-battery systems. The sources of this hydrogen would be water electrolysis with off-peak nuclear of hydro power and eventually solar or wind power. Because of the high efficiency of this option, even on-board storage of compressed hydrogen provides an adequate driving range and fuel costs are already competitive with gasoline or diesel oil used in conventional internal combustion engine systems. Moreover, deployment of a refueling infrastructure of dispersed electrolyzer systems faces no major economic or logistic obstacles.
Growing availability of useful energy services has been the basis of the steady improvement in the quality of life in the industrialized world. Its extensive energy infrastructure offers many pathways to sustainability without impairment of the productivity gains and increased physical, economic and social mobility that are the basis for further advances in human well-being. Therefore, a key element in achieving further human progress is bringing the benefits of electrification to all of the world`s people. The largely U.S.-based independent and utility-affiliated global power producers are meeting this challenge-often aided by privatization and restructuring of state-owned enterprises. Certainly, over the next 25 years, coal-fired generation will continue to play a major role in the electrification of China, India and other coal-rich developing countries. Subject to further substantial investment cost reductions and abatement of the global warming hysteria, the new clean coal technologies may also capture a significant share of relatively near-term baseload needs in low coal cost areas. However, there remains a need to provide electricity to the two billion people not served by any commercial energy infrastructure. Such distributed generation options as small photovoltaic-battery systems that power a few 25 W light bulbs, a radio and other devices would greatly improve their quality of life. Clearly, universal availability of electricity in ever greater amounts should be a key policy objective of the international agencies concerned with economic development.
Implementing this vision of an electrified, sustainable global economy serving 11 billion people by 2100 will require tremendous amounts of capital and an unprecedented willingness of the power industry to take risks and develop new alliances with other energy industries. The most effective way to minimize these capital needs and risks is through adequate investment in research, development and demonstration. Technology has been and will continue to be the enabling force that makes the global energy system capable of meeting rising demands at declining real prices, increased efficiency and sharply reduced environmental impact.
The future of surface transportation is also linked to power supply issues since it now seems quite clear that electromotive technologies offer the most promising route to sustainability and cost-effective efficiency gains.
Henry R. Linden received his bachelor`s of science in chemical engineering from Georgia Institute of Technology, his master`s of chemical engineering from Polytechnic Institute of Brooklyn and a doctorate degree in chemical engineering from Illinois Institute of Technology (IIT). He has been an IIT faculty member since 1954. From 1947 to 1978 Dr. Linden served in various management capacities for the Institute of Gas Technology, including four years as president and Trustee. He was instrumental in the organization of the Gas Research Institute and was its first president. He continues to serve GRI as executive advisor and a member of its advisory council. In addition to his activities in research and education, Dr. Linden has served on numerous boards of directors.
Dr. Linden is a member of the National Academy of Engineering and a Fellow of the American Institute of Chemical Engineers. He has served on many federal advisory bodies dealing with energy policy, technology and regulations. He has written and lectured extensively on U.S. and world energy issues and has authored or co-authored more than 200 publications and 27 patents.