Conservation energy - ACS Publications

Conservation. Energy. Harriet V. Taylor. Miami University, Hamilton, OH 45011. In spite of recent embargoes (1973-74) and cuts in pro- duction and exp...
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Conservation Energy Harriet V. Taylor Miami University. Hamilton. OH 45011 In spite of recent embargoes (1973-74) and cuts in production and exports (1978-79) by oil-producing nations, in spite of a continuing upward climb in prices of imported oil after a quadrupling of costs in 1973-74, in spite of diminishing domestic reserves of petroleum and natural gas, the U. S. continues its profligate consumption of energy in 1980 (Table 1). With 6%of the world's ~ooulation.our share of the world's energy use is still almost 50%.We import roughly half of the oil we use-about 25% of our total annual enerev -.suoolv. ... Our balance of payments, and hence our economy and the international monetary system, our national security, and our image abroad all suffer as we pay in excess of $200 million per day for our energy imports. Outlook on Conventional Forms of Energy There is little hope that domestic production of natural gas and oil can he maintained a t its current level over the next several decades. Our readily accessible supplies of these fuels are fast d i s a ~ ~ e a r i nEnhanced g. recoverv from old sources and energy than current supplies. Although the U.S. has an abundance of coal and hence no absolute energy crisis, there is a crisis in our supply of liquid fuel, petroleum. Dependent on this source of fuel oils and gasoline are virtually our entire transportation network, a large fraction of our space-heating equipment, many industrial process heat- and steam-generating facilities, and even a substantial number of electricity-generating plants. In the last several years some formerly oil-fired steam generators in industries and utilities and some space heaters have been converted to natural gas - or coal. However, natural gas woolies .. also dw~ndle,pro\,idinz at lw;t i i short-term w a p c m w to the short:laes of oil; and envinmmmtal concernsand amhi~uities in yovertment policy haw: ~)rtlvmtedcoal frwn nsiuminR a larger role in energy supply. Current federal policies emphasize synthetic fuels-making liquid and gaseous fuels from coal and oil shale. Because increased mining and conventional uses of coal are associated with increased environmental concerns (subsidence from underground mining. acid drainaee into eround water. intread use and poll&m of water aiready inshort supply, k i d rain, increased particulates and atmospheric carbon dioxide

Table 1. Enerav Facls. U. S.. 197916 ) Fuel

Consumption

Petroleum Natural Gas

Coal Electricityd

6.7 X loe bbls (37.1Q8) 19.4 X 10'2R3 (19.80) 662.5 X 10etonsr (15.2Ql

Total

Reduction

47.4 3.5 X lo9 bbls (20.60) 25.4 19.6 X 1012n3 (20.00) 19.5 775.8 X loe tons (17.80)

Wdmpower 257.1 X 1OSkWh

4.1 257.1 X log kwh

(3.201 234.8 X lo9 kWh (2.801

3.6 234.6 X lo* kwh

Nuclear

Geolhermal and Mher 3.9 X lo9 k w h

Imports 3.0 X lo9 bbls

1.2 X

0.1 3.9 X loe kwh

(0.101 '1 0 = 1 quadrillion Blu = 1 0 ' ~ m %.os X n'natural as,e x a r m

and the concomitant probable climatic changes), various technologies for coal gasification and liquefaction are being developed. Certainly a long-range partial solution to the problem, these synthetic fuels are not yet in the pilot-plant stage, hence are not the answer to current and immediatefuture shortages of fuels. They also will enter the market a t much higher prices than we currently encounter for similar fuels. Appn~ximately4'; id our imergv needs is now ;upplied by ntlclenr power-a source onlv oielectricitv (ilhout 129~of that i~rod~lceh in 1979). Enrly 1 6 7 ~projections s and plans, such as ''Project Independenw," called for 30-41"'u of the nation's electricity to h e produced from atomic energy by the late 1980's and up to half hy the year 2000. Due larcelv - . to citizen concerns regarding the safety of nuclear power plant operations (heightened hy the accident a t Three Mile Island), shortand long-term storage of soent fuel. and nroliferation of- nuclear weapons, little progress has bekn made in licensing new plants or granting construction permit+. In f a d , nuclear-power ~

Volume 58 Number 2

Februaw 1981

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output decreased in 1979 due to the TMI reactor shutdown which was followed by downtime for safety checks of similar reactors. As of Occoher 197R ( I , I). I I I ) . 71 nuclear power p l a n t had operating licenses; ns of .luly l!IXIl (5). 67 hold licenses : ~ n d three more have permission to conduct low-wwer testing prior to licensing. In 1978 approximately 9oplan& had been &&ted construction permits; today that number is 85. In 1978 about 40 plants awaited construction permits; today 11. Reasons for the slowdown are the concerns mentioned above and a decrease in the rate of growth of electricity consumption, causing investments in the nuclear-power industry to he risky. Since the lead-time for on-line Dower ~roductionfor an atomic ~~~-power plant is 10-15 years, new conventional fission reactors will be of little heln in rewlacine fossil fuel-generated electricity until the 1990's a t the eailiest. Two other tvpes .. of nuclear reactors are technoloaies of the future: breeder lission re;rcu,rs and fusion reactors. Neither of these will likelv he unline before 2000, and possibly not I'w a much longer time. In summary, over the short term, none of the current conventional energy sources appears able to mitigate our problems of oil supply in particular and declining energy reserves in general. Even as new, alternate-energy sources and technologies are explored and developed, conservation of our present resources must play a major role in our energy thoughts and practices over the next several decades. ~

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Transportation

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Conservation Energy Conservation is an alternative energy source like oil, gas, coal, and nuclear power. I t is estimated (1-4) that, by improving efficiencies with current techniques and technologies, we could cut energy consumption 30-50% by 2050 while maintaining or improving our standard of living. Substantial changes in lifestyle could further decrease our energy utilization. It is this latter kind of unnecessarilv harsh austeritv program, proposed in the past by the federal government and ochers. which citizens arr unwillina- to accept and which has given conservation a had name. Althouah arowth in energy consumption and gross national product h l s t k a l l v h a w I W n s~ s ~ ~ m robe & I tightly coupld, recent studies indicnrc. that k omtinr~edsteady rise in GNI' can be sustained with a decreasing rate of energy input. The key is increased efficiency in energy -~ use, the most significant form of conservation. There are two definitions of efficiency used in discussions of conservation: "first law" and "second law" efficiencies. "First law" or conventional efficiency is the ratio of net useful enerev -.outout to total ~ r i m a r venerev inout. Our overall conventional efficiency in the U. S. is.aho;t 36%; the antomobile is rouehlv " " 15%efficient bv this definition, most thermal--electric power plants about 33%, conventional nuclear-electric power plants 30-40% efficient (2, p. 34). "Second law" efficiency is defined as the ratio of the thermodvnamic minimum energy required to the actual enerw used to perform a give^^ tusk. There are, of course, prohlems in defining the task rind ill mlrulating theoretical minimil. Our overall national second-law efficiency is estimated a t about 8%; an increase to 20-25% is thought possible (2, p. 35). Imnrovements would come as we owtimize tvoes of enerev ".inout . for particular tasks. The recent studv bv the Union of Concerned Scientists (2. p. 16) predicts r h a ~we can achie\e independence from 01'KC oil imports hv s Isr;imr,rtrwment in overall energy efficienw, whileea 25%-increase &uld free us from all oil;hportati'i (which may not be desirable). Tapping sources of conservation energy is not without difficulties. The barriers are for the most part not technological but political, social, institutional, and in some cases economic. Conservation is decentralized and diffuse in character, dependent upon individual efforts. I t is not a concrete fuel like other sources; not exciting and, therefore, not easily ~~

championed by politicians, governmental policies, or scientists. I t has not been allowed its rightful place in the market. In order to make conservation energy a viable alternative, the public must be awakened to the need and must be educated to its potential; and governmental pricing policies and support systems for various energy forms must be drastically altered. Following are pictures of present consumption and potential saving; in four overlapping sectors of the American economy: transportation, manufacturing, residentiallcommercial buildings, and electricity

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The transport sector continues to use roughly one-fourth of the energy consumed annually in the US. Ninety-seven percent of this energy is in the form of liquid fuels (one-half the oil used per day in the US.); one-ninth of the world's daily consumption of oil fuels our automobiles. Consumption in this arena in 1979 was down onlv 1.1% from 1978 (6).but in the first five months of 1980 is f.4% lower than during the same period in 1979 (7).This decrease reflects higher auto fleet efficiencies, increased fuel costs, and greater consumer efforts a t conservation. Automotive Transport Since the automotive industry is in the hands of a small number of producers, decisions about energy efficiencies are fairly centralized. Before the 1973 oil embargo, due to the low cost of fuel, there was little incentive to increase mileage capabilities. When fuel efficiency became a matter of national concern, the federal government mandated fleet-average minimum mileage standards for new cars (Table 2). These requirements so far have been met by the auto makers. Given the 10- to 15-vear lifetime of an automobile. the imorovements in efficiency are not immediately reflected in fuel-economy statistics for the total domestic automobile fleet. However, it is thought that annual fuel consumption by our automobiles could remain constant over the next 30 vears even if the national mileage driven increases by 50-100% as expected (due to increased numbers of drivers and average - miles driven oer auto) (3, p. 85). Efforts have been made in recent months by cities, states, businesses, and private parties to organize 'ndlor sponsor carpools and vanpools (carrying a 1 2 passengers). Substantial reductions in gasoline usage result, a n d emphasis on these alternative commuting modes should be increased wherever possible. Energy savings have been and can he further realized by reductions in averaee is rouehlv" pro" weieht (nerformance .. . portional to weight), engine power, aerodynamic drag, friction losses in tires (less with radial than conventional tires):. bvimproving engine and transmission design; by reducing driving speeds; by improving maintenance of the fleet; by increasing load factors (more people per vehicle mile); by increasing use of public transportation where feasible. Those technological improvements which are currently possible will probably have been made by the end of the 1980's; after that new, more expensive technologies will be required to make substantial changes in fuel economy (4, pp. 146-147). Immovements in fuel efficiencv are accomoanied bv" hieher levels of pollution or higher costs to control the emissions, frustrating

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Table 2.

Federal Minimum Mileage Standardsa

Year 1978 1979 1980 1985 .Reference

( f l , p. 150.

Fleet-Average Minimum Mileage 18 19 20 27.5

MPG

efforts a t conservation. Estimates of total ~ o s s i b l e(hut not necessarily probable) energy savings throughout the automotive sector in the next 20-30 vears, given varying degrees of public and governmental dedication-to m o r e e f f k e n i use of energy, range from maintaining the status quo to saving 20-50% over current usage. Barriers to realizing maximum savings are the low cost of fuel and the concomitant lack of incentive to improve efficiency; the end of easy technological fixes in the near future; the increasing use of lightweight vans and trucks as passenger vehicles (less efficient and just beginning to come under federal nerformance regulation): the unwillineness of manv consimers to give up ;he comfort and relativesafety of large;, less fuel-efficient cars for smaller ones: the lack of a governmental policy which stresses the need for c o n s e r v a h by offering strong incentives for increasing energy efficiency. Other Modes of Transportation Other areas of the transportation industry, besides private passenger vehicles, also can show increased energy savings. Increasing the passenger load factor, the most critical parameter in planes. trains. and buses. drasticallv - imoroves . energy use per passenger mile. Moving freight by rail is four times more efficient than hv truck and even more so than hv air. Air passenger travel is ;bout half as efficient as that h i train; short distances by high speed trains can he travelled almost as rapidly ashy ;laneat half the energy cost (2, p. 46). Except for increasing the number of passengers carried per vehicle mile, all of the above require huge capital investments to make major changes in this economic sector Manulacturlng In 1979 the industrial segment of the economy accounted for 37.2% of the total U. S. energy consumption, up slightly from 1978 (6).More important, energy input per unit of output in the U. S. has declined since 1950, dropping almost 20% between 1973 and 1979 (3, p. 96). Since the industrial sector measures its success in the-form of profits, it has strong incentive to increase its energy efficiency. The major forms of conservation in industries are (1) improved housekeeping; (2) waste recovery of both heat and materials; (3) new, more efficient technologies. Some of these can he introduced into already existing plants (retrofitting); some will require new facilities and hence will not contribute appreciably to short-term energy savings. Housekeeping Improvements in housekeeping include optimizing lighting and space heating, maintaining equipment for peak performance, turning off lights and equipment when not in use, reducing heat losses in buildings and in manufacturing processes. These remedies often require little capital investment and can easily save 10-15% in energy use. An American Can nlant reduced enerev consum~tionhv 55% with an investment of $73,000 and ;annual savings df almost ten times that much. An autmotive-parts manufacturer spent $50,000 on upgrading housekeeping and has since saved $1.2 million a year. Other companies have cut consumption by 1 0 4 0 % with little capital input and with suhstantial savings (I, p. 153). Waste Recovery (1) Recouery of high-temperature waste heat for use in low-temperature a .~.~ l i c a t i o (lower ns temperature processes. space heating, water 11eari11~) ran reduce energ). inputs 5-llI'i in enerev-intensi\.e ind~~strw.; I:!, 1, 961. This usualls . reauirrs . retrofiZng of existing facilities,'; capital-intensive proposition. (2) Cogeneration of steam and electricity is the premier example of waste-heat management. Normal process steam, usually required a t about 400"F, is generated in oil- or natural gas-fired boilers a t much higher temperatures (3600DF),an

obvious waste of thermal energy. One method of cogeneration would use these higher temperatures to produce a stream of very high-pressure steam to generate electricity by turning turbines; the effluent stream of lower pressure and Lemperature "waste" steam could then he used in the manufacturing orocess. Onlv about half as much enerev is reauired to cogeneratr pncess steam and electric~tyits is required 10 provide t h < ma w w a t ~ l v( I . D. 159). 11 nml-luelrd icrnwntors could supplant current oii- and gas-fired boilers (the necessary technology is not now available), the liquid-fuel shortage could he partially alleviated. Estimates suggest that over 20% of our industriallv-consumed enerw -. could he saved by sound capital investments in cogeneration. In addition to saving energy, cogeneration produces lower levels of air and thermal water -

But there are problems in increasing the amount of industrial coeeneration., again of the institutional rather than technological type. The pricing structure of utility-generated electricity (lower rates for larger users) and the generally low cost of this energy form favor the status quo. Also, utilities are often unwilling (or legally unable) to purchase extra electricity produced by industries, although new laws in some states are forcing utilities to cooperate. Additionally, many industries simply do not want to he in the electricity-generating business and thus fail to realize the potential savings in cogeneration. A second type of cogeneration entails the piping of waste steam from a generating plant to homes and commercial buildings in a small area to provide heat and hot water. Although these systems are fairly common in Europe, little use has been made of them in the U. S. In a few cases, a utility's waste steam is purchased by and piped to a nearby industrial plant for use as process steam. (3) . . Resource recouerv and recvclinc-of " .paper. . . glass. . aluminum, and other metals-save energy compared to the processes of extracting and refining raw materials. Much of the paper industry burns wood and paper scrap to generate process steam and for space heating. Recycling aluminum requires &7% of the energy needed toproduk the metal from the ore; copper and steel use 9% and 14% respectively (2, p. 43). Glass can he recovered and recycled in hottles and used in road-paving materials. Newspaper which is shredded and treated with fireproofing is blown into buildings for insulation. These processes not only save energy hut also natural resources. Unfortunately, some governmental regulations and taxing policies favor the use of raw materials rather than the more efficient recycling.

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New Technologies Many European industrial processes are carried out with appreciably leis energy input per unit output than analogous U. S. processes; in West Germany, 42% less energy is used per ton of naner nroduced. 32% less ner ton of steel (2. D. 42). Much of ;he ~uropean'steelindustry was built af& 'Worl'd War I1 with state-of-the-art technoloev: manv of our steel plants predate the War and have norbeen improved suhstantially since. Hence, a t least some of the differences in energy input are readily explained. New processes and/or new plants could improve fuel use from 10-9090 in enerw-intensive -. manufacturing processes, e.g., making cement, smelting aluminum, enriching uranium, refining petroleum (3, p. 96). Economically-feasible energy savings in the industrial sector by the year 2000 are projected to equal about 30% of recent consumption levels. This savings will not be realized without large capital investment and without government incentives. However, analysis suggests that an investment of $40 billion more would he required for development of conventional energy sources than would he necessary to save an equivalent amount of conservation energy (I, p. 161). ResidentiallCommerclal Buildings The residentiallcommercial sector's energy requirements, Volume 58

Number 2

February 1981

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36-40s of our annual consumption (20%residential), provide heat, air conditioning, light, and hot water for homes, buildings, and factories. Projections for potential savings in this sector range from 30-70%. Because building replacement is such a long-term proposition, retrofitting of existing structures will contribute most to the conservation-energy pool in the next several decades. Retrofitting

The IBM Comoanv a camnaien . . heean .. . .. in 1973 to cut enerw ... use by lo? in :Xi i n r t . ~ I l . n ~ ~o ~~ T~ Os Rthe I country. By 197: consumotion a.;~.;:I!+'; Lmrr :I! il .~\.inosof $90 million, tat,. t h i r d s o > t h e ~ a r l ~ ~ r ~ a > < caui tr hr ~ve& t l ? :littlecapital inve-1ment. In \\'aahinct~~ll. I I. i'., 211exixinq house was retrofitted with insulating &vices and air leaks &gged, yielding a 35% decrease in energy use. Consumers in the state of Washinaton have been able t o purcllaw firm the \!'ashingron ~ a t u r a i C a a Company a k l t I,, inwlntt iht, nrtir. to rhange to a pilotless natural gas furnace and to install a day-night thermostat, leading to an average 36% reduction in heating energy for those participating in the program. A five-year study of a New Jersey community found an average 67% reduction in spaceheating energy requirements when houses were retrofitted with insulation packages and air leaks were minimized (I,pp. 169-171). At the present time as many as 30% of private residences may be without any insulation: as many as 67% may he inadl ~ , of these eq"ately protected ( I , p. 170). ~ n f o r t ~ n a t emany homes are owned by citizens who cannot afford to install insulation packages. LOW-interestfinancing, possibly by utility companies, and education regarding the long-term benefits of relatively simple measures are needed. Consumers cannot run energy audits on their homes without assistance, and trained nersonnel are in short suoolv. .. . The high rate of tnrnover in home ownership exacerbates the problem; the investment in home imorovement mav" not nav . -for itself over the lifetime of the owne;ship. New Buildings The sealed, artificially lighted, heated, and cooled buildings of the 1960's and 1970's are giving way to new designs which are far less enerev intensive. Aooronriate .. . window design and placement and;ptimal use of overhangs reduce neids for unnatural lighting, heating, and cooling; and use of new construction materials decreases the energy expenditure in new homes and commercial buildings. Businesses are discovering that most space-heating needs can be met by utilizing waste heat given off by lights, machines, and people. New energyefficient appliances can cut electricity needs substantially. Installation of heat pumps, which replace electrical-resistance heaters, and zoned temperature controls produce substantial energy savings. Electricity Electricity is 3 hixh quillity wrmdary energy source, usuallv generated In fos~l-(ilrl,n~~(.lear, Doww . ur hvdroelectric . plan&. In 1978 roughly 3l%of our primary energy consumption was used to produce electricity (2, p. 39). At least twothirds of the input energy is lost in the production and transmission of the electricity to the consumer. Because of its high thermodynamic quality and the great inefficiency of its delivery, electricity should he reserved for those applications where it is essential: lighting; operation of electrical motors, appliances, refrigeration units; electrolytic and electrochemical processes in industry; and possibly air conditioning. Electricity is wasted energy as it is used in space and water heating, cooking, clothes drying, industrial process steam and heat sources. Primary fuels are far more efficient in performing these latter tasks. New appliances are being designed and constructed with efficiency in mind. Some major appliances must now bear "energy efficiency ratings" to help consumers make the best 188

Journal of Chemical Education

choice for long-term benefits. Of course attention to "housekeeping" details is also beneficial in minim~zingelectricity consumption.

How to Make Conservation Work There is a general agreement in recent major studies that conservation is our best short-term source of energy. Increased efforts on many fronts will be required to realize its potential. The orice of enerev must continue to rise. a t least until it reaches the le\,el of replacement C U ~ (:rt..u( I r incelitiws must he oiiered tu individuals, b u s m t w . ~.rnd . I I I < I U - ~ I M : t.) emolov as many energy-saving habits and devices as are economical& sound. Some governmental regulation, such as fleet-average mileage standards and possibly minimum appliance-efficiency standards, will probably be necessary. A campaign to inform and educate the public must be waged to present the prohlems inherent in our importing vast quantities of oil and the prospects held by conservation energy. Historically, the American people, when informed, have responded to adversity with ingenuity and resourcefulness. It is time we do so again. The recent Haward Business School Report concludes that ( 1 , P. 182) The United States can use 30 or 40 percent less energy than it does, with virtually no penalty for the way Americans live-save that hillions of dollars will be spared, save that the environment will he less strained,the air less polluted, the dollar under less pressure, save that the growing and alarming dependence on OPEC oil will he reduced and Western societv will be less likelv to suffer internal and international tension. Update The first half of 1980 has seen a changing picture in petroleum consumption in the U.S. Conservation and sharply increased prices for imported oil are the bases for lowered consumotion rates. reductions in imnorts (down 11%over the first 5 months of tks year from a year ago (7)), and a temporary surplus of petroleum inventories. Consequently, gasoline and home heating fuel prices have leveled off and even decreased in some areas. Whether the trend will continue depends on consumer practices and on the international political situation. Literature Cited Author's Note: The general information in this articlc was taken almost exclusively from References (1)-(4). (1) Stobsugh, &hart and yerain, Daniel, (Editors), "Energy Future: Report "1the Rneryy Project at the Harvard Business School? Rsndam House. New York,1979. (2) Kendaii, Henry W., and Nsdia, Steven J., (EditorsJ."EnergyStrategies: Toward aSaisr Future? a Reoort of the Union of Concerned Scientists. Ballinmi Puhliihine Corn. pany.Cambrihgg, MA, 1980. (31 "Energy in Trsnsition 1985-2010: Final Report of the Committeeon Nuclea? and Alternatiw Encrw Systems? National Heseareh Councii, Nslionsl Academy of Seicnas, W. H. Freeman and Company, Sen Francism. 1980. (4) Sehurr. Sam H.. (Project Dirarfor1,"Enemy in America's Future:TheChaiasBafore Us" published for Reaoureu for the Future by Johnr Hupkins University P r m , Baltimore 1979. (51 Nuelear Rw~laloly Cornmissisionasquoledin lheChiropo n i b u n ~M. i o n 5, p. 1. July

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