The following NASA publication received considerable publicity and was cited by opponents of nuclear power. Consequently it drew the ire of nuclear proponents in Congress, who put pressure on NASA funding to stop its dissemination. Thus, although the paper had undergone in-house review and had been approved by the director of Goddard, a -completely unsuccessful- attempt was later made by the Agency to discredit it. At this point I filed a successful grievance action, the result of which was to confirm my complete scientific freedom to publish as I wished. However, the most satisfying outcome of all was the decision by the Potomac Electric Power Company to not build the proposed Douglas Point plant, which was the subject of this paper.
R. F. Mueller
ENERGY CONSERVATION ALTERNATIVES TO NUCLEAR POWER, A CASE STUDY
byRobert F. Mueller
Goddard Space Flight Center
Greenbelt, Maryland 20771
ENERGY CONSERVATION ALTERNATIVES TO NUCLEAR POWER, A CASE STUDY
It is demonstrated that in the Washington Metropolitan area electric resistance heating and commercial lighting represent the greatest demand factors on the projected increase in electrical generating capacity. By contrast recycling, pollution control, increased services to poor people and the Metro mass transit system demands will be relatively minor.
By use of conservative assumptions a quantity of electrical generating capacity in excess of that of the proposed Douglas Point nuclear power plant, or 2,200 megawatts, can be saved through the avoidance of electrical resistance heating and the institution of greater lighting efficiency. Many additional and alternative savings of energy and generating capacity could also result from such strategies as total energy and solar heating and air conditioning.
ENERGY CONSERVATION ALTERNATIVES TO NUCLEAR POWER, A CASE STUDY
The prodigious U.S. appetite for energy has raised the dilemma widely known as the "energy crisis." Paralleling this crisis in resource use is one of environmental degradation engendered by the pollutants which emanate from our technology. Although energy problems and pollution are becoming more apparent with each passing day, the manifold connections between them are only beginning to be appreciated. The relation between the known forms of pollution and the excess energy content of pollutants has been stressed (Mueller,1971). Also, the implications for planetary temperatures and the climate of increasing the total technological energy flux has been discussed for some time. It has been estimated, for example (Altman, Telkes, and Wolf, 1972), that with an energy growth factor of 3.37 percent the average temperature of the Earth's surface in the U.S. could be raised 2.5 deg F by the year 2050 a result of thermal pollution. This result follows directly from an application of the formula P= KT 4, where P is the radiated power, T the absolute temperature and K a constant. Furthermore, these authors estimate that if most of the technological energy is dissipated locally, as in the Northeastern U.S., the regional temperature might rise 2-3 deg F at an earlier date.
One of the solutions which has been proposed for the energy crisis is nuclear fission, and more specifically the light water uranium fuelled reactors now being installed around the country. However, this technology has heightened the dilemma because many deep-seated problems of economics and safety. Not the least of these problems is concerned with the safety of the reactors themselves, since there appear to be substantial risks of the failure of their emergency core cooling systems (ECCS), with consequent catastrophic releases of radioactivity (Ford and Kendall, 1972). In addition there are unsolved problems of nuclear sabotage, in fuel reprocessing and in the transportation, storage and ultimate disposal of wastes. Recently also, the energy efficiency of the entire nuclear fuel cycle has been challenged (Hoffman, 1971). Furthermore, the low thermal efficiencies (< 32%) of the current generation of nuclear power reactors creates special problems of thermal pollution and would add greatly to the level of the regional heat flux mentioned previously.
Although many of the risks and uncertainties of nuclear power are coming to be recognized by the general public, they are generally de-emphasized, and there is much discussion of "tradeoffs" in environmental quality and safety, which are necessary to relieve the energy crisis. Thus, according to the Potomac Electric Power Company ("Nuclear Power, because the world isn't ending tomorrow", 1972) more power is needed because of growth in population, businesses, appliances, mass transit (Metro), pollution control, recycling and to raise the standard of living of disadvantaged citizens.
Late in 1972 the Potomac Electric Power Company (PEPCO), whose service area contains most of the District of Columbia, propose to build a nuclear power plant at Douglas Point on the Potomac River 28 miles south of the National Capital. The plant would consist of two boiling water reactors of advanced design totaling 2,200 megawatts and would include cooling towers to disperse the waste heat1. The nuclear facility, rather than a fossil fuel plant was selected for Douglas Point, according to PEPCO, "... after a detailed and through study of alternatives in 1971." The decision to "go nuclear" was based on the following reasons:
Abundant uranium ore and a "new technology which promised to make nuclear fuel virtually limitless." (This presumably refers to the breeder reactor.)
The nuclear plant would not release smoke, soot, sulfur, nitrogen oxides of fly ash into the air.
In the long run nuclear fuels cost less than fossil fuels.
Certain representatives of the Federal Government have advanced the argument that electricity can be generated efficiently in large power stations, due to "economies of size," more efficient fuel transportation and centralized pollution control. In a recent article G. A. Lincoln (1973), the retired former director of the Office of Emergency Preparedness (OEP), argued as follows:
"On balance, it is not at all clear that electrical power generation and distribution is as wasteful from an overall point of view as some of its detractors would claim."
On balance, however, it is becoming increasingly apparent that the argument for greatly increased generating capacity has many serious contradictions with respect to efficiency and the best uses to which electricity may be put.
For example, the government has stressed in an OEP report (The potential for energy conservation, 1972) that one of the most promising of the energy conservation strategies is the "total energy system" in which the heat wasted through thermal inefficiencies of power plants would be utilized by locating these plants in proximity to residential, commercial or industrial complexes. Yet, at the same time, it is stressed in all current licensing procedures before the U.S. Atomic Energy Commission that nuclear power plants must be kept isolated as much as possible from human populations. Thus the State of Maryland's preliminary environmental impact statement for the proposed Douglas Point nuclear power plant site considers an "exclusion radius" of 1/2 mile, a low population radius of 4.5 miles and a minimum acceptable distance to a population center of six miles (Potomac Electric Power Plant, Douglas Point site. 1973). Thus one of the most wasteful of the electric generating technologies from a thermal efficiency standpoint is also least subject to remediation against this waste. Recently this problem has also been recognized by Meyer and Todd (1973), who point out that heat, unlike fuels and electricity, cannot be transmitted more than a few miles without substantial losses. For the total energy concept to be applicable electrical generating stations must be located to heat loads.
Secondly, the wasteful "burning of 235U has been justified by the hope that the more plentiful 238U will become available through the development of the experimental fast breeder reactor. At the same time experiments go forward on more efficient burners such as gas cooled reactors. [ The safety of nuclear power reactors (light water cooled) and related facilities, 1972 ]. Consequently, if the breeder experiment should fail, it would be increasingly difficult to justify the present generation of water cooled reactors from an energy conservation standpoint.
I propose to show in this report that with the distribution of electricity between the residential, commercial and industrial sectors that prevails in the Washington Metropolitan area, nuclear power, with its attendant risks and uncertainties, is not necessary to achieve an even higher standard of living than is available at the present time, and which is conceived for the 1980's. This conclusion is particularly easily arrived at for the Washington area because of the modest industrial sector, but could, I believe, also be extended to the entire U.S. with full utilization of the conservation strategies available.
ESTIMATES OF POSSIBLE ELECTRICAL ENERGY SAVINGS IN THE WASHINGTON METROPOLITAN AREA
An attempt will be made to show that through the application of a small number of strategies a quantity of generating capacity in excess of that of the proposed Douglas Point nuclear power plant can be saved. In my calculations I shall assume that a reduction in power load of ordinary consumer appliances allows a reduction in generating capacity. The justification for this assumption is to be found in the experience that such appliances as air conditioners represent peak seasonal power loads and that extraordinary sources of transient peak loads such as Metro traction are minor. We shall also assume, with the proper qualifications, that the power load is approximately proportional to the energy consumed over the seasonal interval in which it occurs so that energy and power are apportioned similarly. This is similar to the treatment of air conditioner efficiency by Hirst and Moyers (1973). Of necessity the calculations presented are approximate since they make use of generalized and incomplete data, and since they deal with a projection of generating capacity into the 1980's, which has never been justified by any official body or supported by scientific studies. The calculations thus arrive at a certain distribution of future power demands which depends in part on existing demands but also in part on a process of elimination of a variety of future demands which have been proposed to justify the increased generating capacity. For example, it is concluded that resistance heating, which represents a substantial part of the residential growth in electricity use in the past decade and which is subject to much promotion by the utilities, is a quantifiable factor in the justification of the proposed increase in generating capacity. In this analysis the projected justification demands are investigated and it is found that there is a residue of uses (such as electric resistance heating) which represent major potential demands on energy and generating capacity.
Although the calculations are approximate, they are also conservative in that they characteristically deliberately underestimate savings and omit in the first approximation large sources of savings.
Finally, the conclusions arrived at here go beyond a mere compatibility with high living standards but should act to enhance those standards greatly in both the intangibles of environmental quality and in monitory savings. This would be accomplished through the reduction of thermal and other forms of pollution, the elimination of threats of nuclear accidents and through the introduction of more economical and efficient appliances and structures.
Residential Commercial Trillions BTU Percent Trillions BTU Percent Space Heating 6,675 57.4 4,182 47.6 Water Heating 1,736 15.0 653 7.5 Cooking 637 5.5 139 1.6 Clothes drying 208 1.8 - - Refrigeration 692 6.0 670 7.6 Air conditioning 427 3.7 1,113 12.7 Feedstock - - 984 11.2 Other 1,241 10.7 1,025 11.7 Total 11,616 8,766
Table 1: Energy consumption in the United States in 1968 in terms of end use in the residential and commercial sectors. Adopted from Table D-1 of the OEP Study (1972).
Percent Space heaters 24 Water heaters 11 Clothes dryers 5 Stoves 4 Refrigerators 19 Room air conditioners 10 Central air conditioning 8 Miscellaneous 19
Table 2: Contribution to residential growth of electricity use. Source E. Hirst and R. Herendeen (Large, 1973).
Residential Commercial Industrial National 34 23 43 PEPCO sales 25 50 25
Table 3: Percentages of electrical energy used Nationwide 1971-1972 (OEP Study, 1972 Large, 1973) and as sold by PEPCO. PEPCO figures are rounded off from those provided by the Federal Power Commission for 1972 (McNEAL, 1973)
Generating Capacity in Megawatts Total - Dec. 1972 4,454 Proposed Douglas Point Facility (1981) 2,200 Proposed exclusive of Douglas Point Facility (1981) 3,732 Total Projected (1981) 10,386
Table 4: Existing and Proposed PEPCO electrical generating capacity ("Nuclear Energy, because the world isn't ending tomorrow," 1972), (Federal Power Commission, 1973)
Electrical Sales in Kilowatt hours 1972 Percentage Residential 3,128,686,000 25 Commercial 6,123,238,000 49 Industrial 3,181,396,000 25 Other 152,303,000 1 Total 12,585,623,000 100
Table 5: PEPCO electricity sales in 1972 by consuming sectors. Federal Power Commission Data (McNeal, 1973)
Figure 1: Growth in generating capacity, including projections to 1981, of the Potomac Electric Power Company and in population for the Washington Metropolitan area. The point P represents existing capacity whereas the projection to W includes the proposed Doughlas Point Nuclear Power Plant. The point C is the projection in capacity excluding Douglas Point. The curve P-Q is proposed growth in generating capacity more in line with population growth. The double arrow bar at M refers to the peak power demand of Metro as projected in 1976.
The Growth of Electrical Energy Use
Let us first consider the existing distribution of all U.S. energy uses in the residential and commercial sectors (Table 1), since it is these uses which represent a readily apparent for growth of demand on generating capacity. This is especially true of space heating since it represents a more fundamental demand than lighting and air conditioning, for example. It should be noted that in each case the various forms of direct heat, and especially space heating, dominate. In the residential sector heat amounts to 80 percent of the total, whereas in the commercial sector it represents 60 percent. We also note that air conditioning forms a relatively large proportion of energy use in the commercial sector.
According to the statistics of Hirst and Herendeen as reported by Large (1973a), the growth of residential electricity use between 1960 and 1970 is as given in Table 2. The growth of electric space (resistance) heating forms the largest contribution, and all forms of direct heat amount to 44 percent. Since in the "all electric home" over half the energy is used for space heating (Hirst and Moyers, 1973), it is obvious that the space heating allotment of Table 1 represents a great potential for the promotion of electric resistance space heating in the next decade. This conclusion is also borne out by the PEPCO promotional literature and the result of a Gallup survey ( Crawford, 1969).
Furthermore, the OEP study (1972) indicates that between 1970 and 1980 some 13.1 million new households will be created in the nation as a whole. 5.2 million, or 40 percent, will be electrically heated, and the remaining 7.9 million will be gas or oil heated. Thus electrical resistance heating looms as the greatest single demand on generating capacity.
At the present time one of the largest potential savings in electrical energy and generating capacity is in the more efficient air conditioning, or in the substitution of architectural designs in which less air conditioning would be required. Air conditioning in particular has been responsible for the peak summer power loads which frequently cause power failures. However, Tables 1 and 2 demonstrate that the trend toward all-electric homes would create a situation in which electric space heating would demand greater quantities of power than air conditioning, should the use of resistance heating be allowed to grow. Thus, while air conditioning use of electricity represents some growth potential, it does not represent the potential for peak seasonal loads that resistance heating does.
The distribution of electric energy use on a nationwide basis among the residential, commercial and industrial sectors is shown in Table 3, which also shows the corresponding rounded off values for the PEPCO electricity sales (Table 5).
An analysis by Stein (1972) indicates that lighting consumes 24 percent of all electrical energy sold in the U.S., whereas the commercial sector accounts for about 40% of the nation's electric lighting load (Hirst and Herendeen, in Large, 1973a). Thus lighting in the commercial sector accounts for 0.40 x 24= 9.6% of the total electric energy used in the U.S. Using Table 3 we may then calculate that the percentage of total commercial electricity consumed by lighting is
(100) (9.6/23) = 42% (1)
It seems safe to assume that this figure would hold approximately for the next decade if the trend toward overlighting commercial buildings were allowed to continue (Stein,1972).
The existing and propose growth in electrical generating capacity of the PEPCO are shown in table 4. The present generating capacity of 4,454 megawatts (MW) is supplied by six fossil fuel fired power stations located in Maryland, District of Columbia and Virginia. It should also be noted that in 1981 the total projected capacity exclusive of the Douglas Point plant would be 8186 MW. Thus even without this plant a virtual doubling of capacity would occur in less than ten years. It is my contention that the 8186 MW of projected capacity is a valid target for energy conservation strategies which would obviate the need for Douglas Point. Furthermore, any additional reductions in power load might then be directed toward reducing this 8186 MW capacity itself and so avoid difficulties of pollution and aesthetics which are posed by the fossil fuel plants.
The figures presented in Table 4, as well as statistics on the growth in generating capacity ('Chalk Point PEPCO's newest and largest generating station," 1965) and population growth for the Washington Metropolitan area (Jaworski, Clark and Feigner, 1971) are shown plotted in Figure 1. In this figure P stands for the present capacity, whereas W represents the total proposed capacity in 1981 according to the PEPCO. The point C, on the other hand, represents the projected capacity exclusive of the Douglas Point plant. It is obvious that both curves for the growth in generating capacity rise considerably steeper than the population curve. The dotted curve P-Q defines a growth in generating capacity which would be more in line with population growth since it is one of a family of curves which, although less steeply rising than P-C, exceeds a constant per capita generating capacity.
Table 5 shows the distribution of the PEPCO electricity sales in 1972 as distributed among the various sectors (McNeal 1973). These data have been shown in rounded off form in Table 3 for comparison with the national average. The commercial sector is more prominent in the Washington Metropolitan area and the industrial sector less so than nationwide.
Since the need for the proposed Douglas Point nuclear power plant has been justified in part by the projected electrical demands of Metro, pollution control, recycling, and disadvantaged citizens, it is desirable to inquire into the magnitudes of these demands, particularly with respect to generating capacity.
The question of the electrical energy required to provide for the poor of our nation has been considered by Large (1973b). He estimates that the average annual residential electrical energy of 2200 Kilowatt hours per person for 23 million people would represent only 3.6 percent of the total electrical consumption. Roughly the same percentage value would of course apply to our own case if we assume that the Washington Metropolitan area is at all representative of the nation as a whole.
In the case the electrical requirements of the Metro system it is informative to consider first an existing mass transit system operated by the SE Pennsylvania Transit Authority. According to official figures ( Boorse, 1973), the peak load on this system, which consists of 324.4 miles of track. is 63,000 kilowatts or 63 MW. For the Washington Metro the anticipated peak demand power load within the peak hour of operation is about 260,000 kilowatts for the 32 mile system planned for 1976 (Luhrs, 1973). However, because of the allotment to several different power companies, the PEPCO share is less than 200 MW. Virtually all of this peak load is reserved for traction, with much smaller amounts allotted to air conditioning and other facilities. The peak Metro demand is shown as a double arrow bar on Figure 1 at M.
If we now consider recycling and pollution control, we see that these are closely related. It has been shown (Makhijani and Lichtenberg, 1972) that one of the most important justifications for recycling is its energy conserving character. For example, the recycling of metals generally requires only a fraction of the energy required to obtain them from their ores. Secondly, it may be shown (Mueller, 1971) that pollutants are characterized by excess energy relative to their degradation products, which has been conferred upon them by the manufacturing process, Also, pollution control technologies which consume energy are prone to the same thermodynamic laws as manufacturing processes. Consequently, pollution control which depends on the consumption of energy is likely to fail because this energy will give rise to additional pollution. We may therefore anticipate that successful pollution control and recycling effects will lead to a lowered demand in both energy and electrical generating capacity per unit of production. We shall see in the next section that this conclusion is also compatible with strategies for reducing the consumption of electricity in the industrial sector.
If no increases in efficiency or conservation of energy were instituted in the industrial sector, this sector may be assumed to contribute approximately 25 percent of the future demands on generating capacity.
In summary then we can identify a set of residual demands on the future generating capacity which, if allowed to grow, would be substantial. Foremost among these demands in the residential and commercial sectors are electric resistance heating and commercial lighting. Savings in the industrial sector are based on more complex strategies to be discussed in the next section, but also will depend strongly on recycling and pollution control efforts. Air conditioning also presents a considerable potential for savings, but its potential contribution to peak loads in the future is more limited than heating.
By contrast, the potential for demands on electrical generating capacity by Metro, poor people, pollution control, and recycling appear to be relatively minor. Indeed, recycling and pollution controls should result in energy savings, and the same is probably true of Metro if the total energy expended in transportation is taken into account.
Energy Savings in Electrical Heating, Lighting and in Industrial Efficiencies
Studies by Hirst and Moyers (1973) indicate that if account is taken of generation, transmission and distribution the overall efficiency of delivered electric heat is about 30 percent. On the other hand, the end use efficiency of a gas or oil burning home is about 60 percent if fuel deliveries and burning efficiencies are taken into account. Consequently energy conservation favors gas or oil heating by a factor of two. Thus it would seem to be desirable to avoid the use of electric energy for this purpose and divert it for such highly efficient uses as powering motors.
We shall now make the assumption that the diversion of electric energy from resistance heating uses is desirable and that a fraction of the proposed increase in generating capacity exclusive of the Douglas Point facility2 may be thus diverted since we have shown that electrical resistance heating is one of the major justifications for the proposed capacity increase. i shall also assume that the diversion is in approximate proportion to the electric energy sold as set forth in Tables 1, 2 and 3, except that I shall use more conservative figures. Thus we have seen that electric heating is likely to comprise in excess of 50 percent of the projected energy demand for the residential and commercial sectors. We shall assume however that only 40 percent of the generating capacity may be thus assigned. A further conservatism is introduced by the fact that the peak power fraction demand is likely to exceed the fraction of energy sold for this use3. Then since the two sectors comprise 75 percent of the power sold by the PEPCO we have
(3732) x (0.75) x (0.40) = 1120 MW, (2)
which represents the proposed generating capacity which may be saved or diverted from electric resistance heating to other uses.
In addition to this type of diversion from electric to direct fossil fuel heating, a new technological alternative known as the "heat pump" should be considered (Hirst and Moyers, 1973), since this device could equalize the positions of these different sources of heat from a fuel conservation standpoint. While not yet perfected, this technology would represent an enormous saving of electrical generating capacity. It is therefore an additional alternative to resistance heating.
Stein (1972) has made a detailed study of lighting inefficiencies in commercial and institutional buildings and has concluded that most of these structures are grossly overlighted or make use of inefficient lighting facilities. He writes:
"To summarize, it appears that adequate lighting could be installed in institutions, commercial buildings, schools, and so forth with less than 50 percent of the present light loads."
He further details why he believes this to be a conservative estimate.
If we now regard the Washington Metropolitan area as representative of the conditions to which Stein refers, we may apply his estimated savings to the propose generating capacity exclusive of the Douglas Point facility. Also, because most lighting inefficiency in existing buildings can be corrected, we may assume that the total proposed generating capacity exclusive of Douglas Point is subject to such correction. Then making use of relation (1) we have:
(8186) x (0.50) x (0.50) x (0.42) = 860 MW, (3)
which is the quantity of generating capacity which may be saved by increasing lighting efficiency by 50 percent in the commercial sector the PEPCO electricity sales.
If we now consider the industrial sector, we find that it is generally agreed that substantial energy savings are possible, except that they involve a greater variety of sources. Thus from the OEP study4 (1972) :
"Given sufficient incentive, industry as a whole could easily cut energy demand by 10-15 percent (and probably more) of the projected demand by 1980, primarily by replacing old equipment, using more energy conscious design, increasing maintenance of boilers, heat exchangers etc. It should be emphasized that underpriced energy encourages wasteful energy use."
We now assume that industry represented in the PEPCO electricity sales is subject to this degree of energy saving and that allocations of proposed generating capacity can be made in proportion to these sales. Since existing industry is also subject to the type of saving detailed above, we make use of the total proposed generating capacity. Thus for a 10 percent saving we have:
(8186) x (0.25) x (0.10) = 205 MW, (4)
and for 15 percent:
(8186) x (0.25) x (0.15) = 308 MW. (5)
If we now add5 the results (2), (3) and (4), we obtain as the total potential saving in generating capacity of 2185 MW, and if we add (2), (3) and (5), we obtain 2288 MW. Thus we have demonstrated that if only residential and commercial electric resistance heating, commercial lighting and a modest industrial saving are considered, a quantity of electric generating capacity equivalent to the proposed Douglas Point nuclear power plant can be saved or diverted to other uses.
In the next section we consider some further possible savings in energy and generating capacity which are either in addition to those presented or represent alternatives.
Additional and Alternative Savings in Energy and Electrical Generating Capacity
The following is a list of potential savings of energy and generating capacity which were not considered in the foregoing analysis :
Installation of total energy systems to serve residential, commercial and industrial complexes.
Improvements in insulation in all structures.
Certain architectural improvements in the residential and commercial sectors.
Improvements in the efficiencies of appliances such as air conditioners and refrigerators.
Improvements in residential and commercial lighting efficiencies.
Replacement of residential and commercial electric resistance heating devices installed before 1973.
Installation of solar space and hot water heating and air conditioning in some residential and commercial buildings.
Encouragement of energy saving life styles (such as moderation of building temperatures and turning off lights.
It is generally recognized that the use of total energy systems is one of the most viable options for energy
conservation when electric generating stations can be located in proximity to human habitations and commercial and industrial centers. It has been estimated that the thermal efficiencies of such decentralized power plants are at least 25 percent greater than those of large power plants (Large, 1973a), since the rejected heat is utilized in heating buildings and in industrial processes. If we regard the quantity of heat liberated in generating the proposed expanded capacity exclusive of the Douglas point plant, if we assume a 40 percent thermal efficiency and disregard distribution losses, then we obtain the following for the total rate of additional useful energy production in megawatts:
(3732) x (100/40) x (0.25) = 2330 MW.
The heat component of this rate of energy production might be seen as an additional alternative to the electric heating as well as some of the industrial generating capacity which is the subject of the discussion leading to relations (4) and (5).
It is also clear that some energy saving could result from improved insulation for residences. Hirst and Moyers (1972) estimate that more than 40 percent of the electrical energy of space heating could in this way be saved. A very conservative estimate would be that space heating constitutes 24 percent of the electrical power load by analogy with Table 2. Then if we assume applicability to the proposed growth in generating capacity exclusive of Douglas Point we obtain:
(3732) x (0.25) x (0.40) x (0.24) = 90 MW.
If we assume a more realistic figure of 50 percent for the space heating allotment, this is more than doubled. However, it should be noted that the energy saved in this way is considerably less than that saved by avoiding electric resistance heating.
Savings which may be realized through architectural improvements have been discussed in detail by Stein (1972), who found great improvements possible in larger commercial buildings. In some cases these savings amount to more than 50 percent in terms of energy consumed for heating, lighting and air conditioning.
Although air conditioning would no longer engender peak yearly loads under the proposed PEPCO expansion, substantial savings in energy and in summer generating capacity are possible through increased efficiency. Hirst and Moyers (1973) have compiled statistics which show that the efficiency of some air conditioners presently marketed range from less than 5 BTU/watt hr.to 12 BTU/watt hr., with an average of 6 BTU/watt hr. These authors estimate that if the average efficiency were increased to 10 BTU/watt hr., a saving of 40 percent in connected load and energy would be achieved on a nationwide basis. From Table 2 we see that room air conditioning represents 10 percent of the recent growth in electricity use. The lifetime of a room air conditioner is about ten years (Hirst and Moyers, 1973), so that most existing air conditioners should be replaced by 1980. From Figure 1 we note that the projected growth in generating capacity from 1960 to 1981 exclusive of Douglas point is 6686 MW. Consequently the potential savings which may be achieved in the residential sector are:
6686 x (0.25) x (0.40) x (0.10) = 67 MW.
If we assume that the same savings are applicable to both the residential and commercial sector we obtain:
(6686) x (0.75) x (0.40) x (0. 10) = 201 MW.
These figures are however very conservative in terms of total air conditioning savings in that they do not consider central air conditioning.
The utilization of solar energy for space heating and air conditioning is a major alternative to direct fossil fuel heat and to the growth of electrical resistance heating. The OEP study (1972) indicates that by 1981 about 40 percent of 13.1 million new households constructed since 1970 will be electrically heated. Tybot and Lof (1970) calculated that the solar energy falling on the roof of a typical American house is nearly ten times the space heating demand for such a house. Furthermore, these authors point out "that the most suitable areas for solar house heating are those with moderate to severe heating requirements, abundant sunshine and ideally, heat needs throughout most of the year." These are characteristics which would seem to apply quite well to the Washington Metropolitan area, which incidentally, is already the site of the famous Thomason solar heated home (Large, 1973).
Altman, Telkes and Wolf (1972) have considered the case of the solar equivalent to the all-electric heated and air conditioned home. Their study shows that the substitution (in new structures) of solar energy for all-electric service could save as much as 72 percent of the total energy when the need for some make-up energy in the solar home is taken into account. At 34.6 percent efficiency of delivered electric energy the proposed 3732 MW of added capacity exclusive of Douglas Point would correspond to a total energy production rate of :
(3732) x (100/36.4) = 10,260 MW.
Electric space heating accounts for 50 percent of the energy requirements of an all-electric home. Thus the rate of energy production of a fossil fuel power plant corresponding to space heating of the residential sector would be:
(10,206) x (0.25) x (0.50) = 1280 MW.
With the substitution of solar heating, 70 percent of this, or 896 MW, could be saved. Additional savings in the rate of heat production and avoidance of thermal pollution could be achieved by use of solar energy for water heating and eventually in heating buildings in the large commercial sector. Also, although the utilization of solar air conditioning in the summer season would have a smaller effect on the rate of heat production than does heating, it would provide additional energy savings. Finally, the moderate costs of solar heating when compared with other methods has recently been demonstrated by Lof and Tybout ( 1973).
SUMMARY AND CONCLUSIONS
It is concluded that there is a critical need to consider energy conservation as an alternative to nuclear power because:
Nuclear power presents serious problems of possible accidents, in fuel reprocessing and in the transportation, handling and disposal of nuclear wastes.
The economics and energy budget of the nr fuel cycle are doubtful.
The uranium fueled "burner" reactors currently being installed are thermally inefficient, resulting in much local thermal pollution and in energy waste. The proliferation of such plants may also add dangerously to the regional and planetary heat flux and lead to climate modification.
Because of the necessity of isolating nuclear power plants for safety reasons, their waste heat cannot be readily reclaimed as in total energy systems.
The wasteful "burning" of 235U fuel is justified by the anticipated development of the experimental breeder reactor, which is highly uncertain.
The proposed Douglas Point nuclear power plant has been justified on the basis of the following needs:
Metro and mass transit
However, analysis shows that only categories 1, 2 and 3 will make serious demands on generating capacity. Furthermore, the largest demands are likely to be from electric resistance heating of "all electric" buildings in the residential and commercial sectors and from commercial lighting, should these uses be allowed to grow unchecked. By contrast, Fig. 1 shows that the demands of population growth are likely to be much more modest.
It is proposed that by the avoidance of electrical resistance heating, by the institution of more efficient lighting and by modest savings in the industrial sector, electrical generating capacity equivalent to the proposed Douglas Point plant could be saved when such energy saving strategies are applied to the existing and projected capacity exclusive of Douglas Point. Furthermore, large additional and alternative savings in energy and generating capacity could result through the use of solar heating and air conditioning, total energy systems and through increase efficiency of insulation, appliances and construction designs.
Finally, none of the proposed energy conservation strategies would result in a diminished standard of living. Rather, energy conservation would lead to a more livable environment and would probably result in large monetary savings to consumers.
The writer gratefully acknowledges the help of Dr. David Large in making available certain literature and the results of his own studies before their publication. His critical reading of the manuscript is also appreciated.
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1Cooling towers present their own problems, such as the dispersal of salts on land.
2It is inferred that the expanded generating capacity exclusive of Douglas Point would represent fossil fuel facilities. Also, because of the efficiency ratio 60/30, the diversion would not represent an increase in fossil fuel consumption for heating.
3Air conditioning contributes heavily to the energy sold.
4Much larger industrial savings are possible according to Berg (1972).
5Winter heating and lighting peaks fall close to each other.