SERl/TP-252-2107 UC Category: 62e DE84000097 Benefits from Energy Storage Technologies Robert J. Copeland, Chairman Ad Hoc Subcommittee on Position Paper of the Energy Storage and Transport Technologies Committee of the Advanced Energy Systems Division of ASME November 1983 To be presented at the Energy Sources Technology Conference and Exhibition New Orleans, LA 12-16 February 1984 Prepared under Task No. 1379.11 WPA No. 431 Solar Energy Research Institute A Division of Midwest Research Institute 1617 Cole Boulevard Golden, Colorado 80401 Prepared for the U.S. Department of Energy Contract No. DE-AC02-B3CH10093 Printed in the United States of America Available from: National Technical Information Service U.S. Department of Commerce 5285 Port Royal Road Springfield, VA 22161 Price: Microfiche A01 Printed Copy A02 NOTICE This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights. SERI/TP-252-2107 BENEFITS FROM ENERGY STORAGE TECHNOLOGIFS Robert J. Copeland L. D. Kannberg R. S. Steele L. G. O'Connell S. Strauch D. Eisenhaure L. J. Lawson L. 0. Hoppie A. P. Sapowith T. M. Barlow D. E. Davis ABSTRACT for that mismatch. The results can provide cost advantages to the user and reduce premium fuel use. The United States is continuing to rely upon Substantial improvements in energy efficiency are nondomestic and nonsecure sources of energy. Large possible with advanced energy storage devices in many quantities of energy are lost as a result of time mismatches sectors, but especially in transportation and residential/ between the supply and the demand for power. Substantial commercial sectors. We have abundant domestic resources in improvements in energy efficiency are possible through the coal, geothermal, solar, wind, and nuclear energy. use of improved energy storage; advanced energy storage can Substituting these alternative energy sources for premium also improve the utilization of domestic energy resources fuels is very possible, provided that the system can econom­ (coal, geothermal, solar, wind, and nuclear) by providing ically meet users' time-varying demands. Improved energy energy in accordance with a user's time-varying needs. storage could accommodate this time-varying demand and Advanced storage technologies offer potentially substantial improve the competitive posture of alternative energy cost and performance advantages but also have significant sources for transportation, electric power, industry, and resi­ technical risk. If even a fraction of the proposed dential energy consumers. technologies reach fruition, they will make an important con­ Energy storage technologies include batteries, tribution to better use of our domestic energy resources. The flywheels, compressed air, thermal systems, and hydrogen. Energy Storage and Transport Technologies Committee of the The state of the art of these technologies is quite varied. American Society of Mechanical Engineers encourages re­ Some are already commercially ready (e.g., lead-acid search, development, and application of energy storage tech­ batteries). Others are being developed (e.g., composite fly­ nologies to reduce imports and energy costs. wheels and molten-salt thermal storage). Still others are in research stages (e.g., thermochemically generated hydrogenl. 1.0 OVERVIEW Advanced technologies offer potentially significant cost and performance advantages and reductions in premium fuel The United States relies on nondomestic and nonsecure use. However, significant technical risks are associated with sources of energy for its needs; this has caused major those technologies, and some are expected to be dislocations in our economy from embargoes, oil shortages, unsuccessful. If even a fraction of these proposed technol­ and increasing energy prices. While the current oil glut has ogies reaches fruition, however, that will be an important resulted in price moderations, the conditions that caused the contribution to making better use of domestic energy embargo could return. Even without a major disruption in resources. imports, spending over $60 billion a year on imported oil has a The American Society of Mechanical Engineers (ASME) significant impact on the U.S. economy and is a factor in the encourages research, development, and application of energy high number of unemployed Americans. Imports provide over storage technologies to reduce im ports and energy costs. 38% of the U .s. petroleum used in 1981, and use of natural ASME recognizes that the roles of government and the gas exceeded domestic supply. All energy imports account private sector are different. ASME encourages government for about 18% of our total energy consumption, although in support for development of advanced energy storage technol­ 1982 the annual energy consumption dropped by 4.1% from ogies to reduce risks and accelerate their acceptance. The 1981 levels and imports of petroleum were reduced to 28% of society also encourages the private sector to assess the :>tate consumption. If we can achieve even more savings in these of the art continually and to furt her develop and apply tech­ two premium fuels, there will be substantial improvements in nologies that are economically viable as soon as possible. our nation's economic and political security. In 1981, the Unityg States consumed in excess of 77 2.0 INTRODUCTION quadrillion Btu (81 x 10 J) of energy. About half of that energy is lost, much of it as a result of time mismatches be­ Storage involves the retention of a resource available tween the supply of and the demand for power. Storing now until a time when it will be needed more or can provide energy in a readily available form is one way to compensate increased economic benefits. Man's transition from hunter 1 SERI/TP-252-2107 and gatherer to sower and reaper-the agricultural Storing energy is important because it reduces the revolution-was important because harvested grains and roots detrimental effects of time. Storage is most effective when could be set aside for use in other seasons. Some common there is a ver y efficient and controllable time lag between modern examples of storage are fac tory inventories, coal energy conversion to a storable form and later utilization. piles as a utility inventory, and refrigerated foods. Energy This allows conversion to the stored form to take place when storage is actually a powerful means of conservation that re­ energy is cheap or abundant, or both, for later use when it is duces the capital and fuel costs of delivered energy. Energy needed. storage both increases the use of capital equipment and In this paper, we describe the benefits that various enables us to use energy that otherwise would be wasted energy storage technologies could provide. The current state without this alternative. of the art of these technologies is briefly discussed, and spe­ Figure 1 represents energy supply and demand in the cific devices are identified that require further research and United States. Petroleum and natural gas are premium development. energy fuels because we must import .a large share of our total requirements for them. A significant percentage of 3.0 ADVANTAGF.S OF ENERGY STORAGE (AND these imports comes from insecure sources subject to embar­ TRANSPORT) TECHNOLOGIF.S goes, shortages, and rapidly escalating prices. Importing large supplies of petroleum has severely affected inflation, Premium fuel consumption and energy costs can be significantly increased our cost of livi ng, contributed to in­ reduced in two ways by storing energy: creased unemployment, and jeopardized our economic and l. Enhanced Energy Conversion Efficiency. Storage political security. improves conversion efficiency by shifting energy Energy is a precious commodity; in its generally used from when it is available but cannot be used to a forms, it is in limited supply. While energy consumption in time when it will be needed. the United States has decreased in recent years, the average 2. Alternative Energy Substitution. All of the energy­ increase for the world has been 3.6%. Third-world countries use sectors exhibit time-varying loads. Frequently, have typical increase rates of 5% to 8%. Thus, competition users select premium fuels (petroleum and natural for energy among the nations of the world has and will gas) to meet the demand, because the capital costs continue to increase its cost. Some of the many limited associated with these fuels are low even though the sources of energy may even be depleted within the next fuel costs are high. Alternative low-cost energy century. Economic conditions require us to strive for sources (e.g., coal, nuclear, solar, wind) can be em­ efficient energy utilization and to shift our energy ployed cost-effectively by using energy storage consumption to more abundant resources. _ technologies to meet v!l.riable loads. 9 At 340 million Btu (359 x 10 J) per person (1981), the We describe potential benefits and how they might be United States consumed more energy than any other country achieved in this section. A successful commercial application in the history of the world. Of what we consume, only 49% requires research and development of storage technologies ends up as useful energy; 51% is rejected for one reason or that have satisfactory (a) cost, (b) performance, (c) safety, another. Many of the reasons for such poor utilization are and (d) operational characteristics. There is substantial doubt related to time. Solar energy is poorly utilized because it is about whether any one technology, especially one in an early not always available. Large utilities suffer inefficiencies state of development, can meet all of these requirements; because the power plants currently employed to meet peak indeed, we expect that many will be unsuccessful for one demands are inefficient for a normal load.