No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Energy Analysis of the Solar Power Satellite
Abstract
The energy requirements to build and operate the proposed Solar Power Satellite are evaluated and compared with the energy
it produces. Because the technology is so speculative, uncertainty is explicitly accounted for. For a proposed 10-gigawatt
satellite system, the energy ratio, defined as the electrical energy produced divided by the primary nonrenewable energy required
over the lifetime of the system, is of order 2, where a ratio of 1 indicates the energy breakeven point. This is significantly
below the energy ratio of today's electricity technologies such as light-water nuclear or coal-fired electric plants.
... r- Morning and afternoon census data on 5 days post-exposure (1, 6, 11, 16, and 21) for (1) Our data indicate that 30-min exposure of adult honey bees to 2.45 GI!z continuous wave r^ • rowaves at selected power densities between 3-50 mw/cm 2 do not significantly affect the survival, longevity, or intra-colony mobility of honey bees. This study was conducted as part of an ongoing program to ascertain possible biological effects of CWM on invertebrates as part of the SPS Concept Development and Evaluation Program (1,2). We wished to determine if short term exposures (30 min.) of the immature stages of honey bee eggs, larvae, and pupae to CWM at power level densities approximating those in the rectennal area would cause adverse mortality, growth, or teratological effects. ...
... Weights of the two colonies never exceeded a 5% difference. Of the 114 gram difference at the conclusion, 37 grams can be accounted for by a greater population of adults in the microwave-treated colony (2,609) compared to the sham colony (2,393). Otherwise, differential brood quantities accounted for the remaining weight difference. ...
... (1) it is a flying invertebrate that cannot be excluded from rectennae, (2) it has a short life cycle and can be reared economically in large quantities so that many generations and large numbers of individuals can be studied rapidly, (3) it has a large number of highly sterotyped behavioral patterns that can be quantified accurately, (4) previous studies have shown that bees are sensitive to various forms of electromagnetic radiation, (e.g., Greenberg et al. 1978, Paul and, and (5) Will honey bees enter a microwave field of intensity equal to or higher than expected in the rectennal area and would they continue to forage during exposure? ...
A honey bee colony (Apis mellifera L.) was exposed 28 days to 2.45 GHz continuous wave microwaves at a power density (1 mW/sq cm) expected to be associated with rectennae in the solar power satellite power transmission system. Differences found between the control and microwave-treated colonies were not large, and were in the range of normal variation among similar colonies. Thus, there is an indication that microwave treatment had little, if any, effect on (1) flight and pollen foraging activity, (2) maintenance of internal colony temperature, (3) brood rearing activity, (4) food collection and storage, (5) colony weight, and (6) adult populations. Additional experiments are necessary before firm conclusions can be made.
... r- Morning and afternoon census data on 5 days post-exposure (1, 6, 11, 16, and 21) for (1) Our data indicate that 30-min exposure of adult honey bees to 2.45 GI!z continuous wave r^ • rowaves at selected power densities between 3-50 mw/cm 2 do not significantly affect the survival, longevity, or intra-colony mobility of honey bees. This study was conducted as part of an ongoing program to ascertain possible biological effects of CWM on invertebrates as part of the SPS Concept Development and Evaluation Program (1,2). We wished to determine if short term exposures (30 min.) of the immature stages of honey bee eggs, larvae, and pupae to CWM at power level densities approximating those in the rectennal area would cause adverse mortality, growth, or teratological effects. ...
... Weights of the two colonies never exceeded a 5% difference. Of the 114 gram difference at the conclusion, 37 grams can be accounted for by a greater population of adults in the microwave-treated colony (2,609) compared to the sham colony (2,393). Otherwise, differential brood quantities accounted for the remaining weight difference. ...
... (1) it is a flying invertebrate that cannot be excluded from rectennae, (2) it has a short life cycle and can be reared economically in large quantities so that many generations and large numbers of individuals can be studied rapidly, (3) it has a large number of highly sterotyped behavioral patterns that can be quantified accurately, (4) previous studies have shown that bees are sensitive to various forms of electromagnetic radiation, (e.g., Greenberg et al. 1978, Paul and, and (5) Will honey bees enter a microwave field of intensity equal to or higher than expected in the rectennal area and would they continue to forage during exposure? ...
Foraging-experienced honeybees retained normal flight, orientation, and memory functions after 30 minutes' exposure to 2.45-GHz CW microwaves at power densities from 3 to 50 mW/cm2. These experiments were conducted at power densities approximating and exceeding those that would be present above receiving antennas of the proposed solar power satellite (SPS) energy transmission system and for a duration exceeding that which honeybees living outside a rectenna might be expected to spend within the rectenna on individual foraging trips. There was no evidence that airborne invertebrates would be significantly affected during transient passage through microwaves associated with SPS ground-based microwave receiving stations.
... The declining output rep- P resents an increasingly dilute fuel source, or a declining energy efficiency for an output device. An example of the latter is the tendency of photovoltaic cells to become inoperable after a time [21]. The remainder of the power curve is simplified because available data on energy-transformation processes are not detailed enough in most cases to allow a more elaborate representation. ...
... A zero discount rate in eq. 1 produces the standard form of the net energy equation commonly used by energy analysts. Most calculations of energy feasibility [21, 351 compare the average annual net output with processing input plus the initial construction energy. The construction energy is divided by the expected lifetime of the system. ...
... None of the examples identified in this study showed scarcity responses. Most of the examples were based on the University of Illinois Energy Input-Output model [25], but only one contained an indication of error tolerances [21]. However, the individual authors used different techniques to assign joint energy costs and to credit by-products. ...
The procedure described allows comparison of various energy transformation processes, including those using fossil fuels, solar energy, and conservation. The procedure allows a determination of the relative feasibility and desirability of each process for producing a surplus of energy beyond the output that could be obtained directly from the process energy (i.e., the energy needed for self-reproduction). The analysis includes all energy directly or indirectly committed to the process, throughout the entire economy.To quantify the feasibility of energy transformation, an input-output ratio was calculated for 44 processes. The calculations exclude fuels transformed directly into energy output. Adjustments were made for differences in quality, end use, and time of use. A low ratio means that the process should receive further research and development funding or else should be dropped from consideration. The input-output ratio of a feasible transformation process may decline with time because of a resource scarcity, indicating a falling desirability. Highly desirable processes, ones with ratios that show the least signs of declining, should also be compared for future use on the basis of their relative effects on labor needs, capital requirements, the demand for critical material, and their environmental impact. Policy conclusions are hampered by an unevenness in the quality of the available data. Nevertheless, a useful and comprehensive method of energy analysis is demonstrated.
... The surge of oil prices and the gradually diminishing crude oil reserves impelled people to search for new fuel alternatives. Net energy analysis was thus taken as an effective means to calculate which alternative energy choice could be most energy-efficient as compared to traditional transportation fuels as well as to identify the net energy gains of an energy technology [29,30]. In 1974, net energy analysis was even written into the federal law (Public Law No. 93-577) of the United States, which regulates that the appraisal proposal of a state-supported energy technology should include the assessment of its potential of net energy production at the commercial scale. ...
Solar power has been widely treated as renewable and carbon-neutral for being free of fossil resource inputs and causing no carbon emissions. Recent studies, however, qualitatively challenged the traditional thinking derived under a local-realism-based perspective. In response to the recent concerns, this study as a continuation of a previous work offers a systems view into comprehending the ‘renewable’ and ‘carbon-neutral’ characters of solar power by the case of a Chinese pilot solar power plant. Under the systems view, a solar power plant is positioned as an organic system fed by ‘nutrients’ from the macro economy that relies on exogenous non-renewable energy resources as environmental support. A quantitative framework for evaluating the renewability and carbon-neutrality of solar power systems is proposed. A package of indicators is also devised, together with a retrospect of the history of methodological development. The non-renewable energy cost is revealed to be in magnitude 1.6 times as much as the electricity produced and the carbon emissions induced are also shown to be remarkable, implying that solar power is not as renewable and carbon-neutral as generally perceived. In contrast to coal-based power, however, solar power still appears as a promising alternative: the non-renewable energy cost and carbon emission for per unit of electricity delivered are revealed as 55% and 64% of that by the reference coal-fired power generation system in China, respectively. The outcome of this work provides a well-adapted assessment framework and adds insights into the intuitive understanding of renewable-based electricity.
... The studies were concentrated on the enormous SPS Reference System [112] with a 5 GW power output, a collector array of 5 km x 10.5 km and a rectenna of 10 km x 15 km. A net energy analysis calculated that this type of SPS could be a net energy producer [67]. The summary assessment [143] of the project concluded that the SPS had the potential to become an important source of electric power, but the initial investment cost was far too high and there were still too many uncertainties in technology and environmental effects. ...
... (Hannon, 1973;Finn, 1976Finn, , 1980Patten et al., 1990). Indirect effects are especially important in the question of net energy: how the energy produced by an energy technology compares with the energy required to produce its inputs (Chapman, 1975;Chambers et al., 1979;Herendeen et al., 1979;Herendeen, 1988). ...
... There has never been any theoretical , thermodynamic reason why photovoltaic cells should not be produced using less energy than they deliver. Since the 1970s, it has been shown that photovoltaic systems can be made (Herendeen et al., 1979; Mortimer, 1991) and are made (Palz and Zibetta, 1991) in such a way that they are clearly net contributors to an industrial energy system. Both technologies for direct conversion of solar energy via photovoltaic systems and indirect use of solar energy, such as wind power plants, can be built today so that they produce the electricity required for their production in about a year or less (van Engelenburg and Alsema, 1994a,b, Alsema, 1996). ...
This paper is a contribution to the discussion on the relation between thermodynamics and economic theory. With respect to thermodynamic constraints on the economy, there are two diametrically opposite positions in this discussion. One claims that the constraints are insignificant (‘of no immediate practical importance for modelling’) and in the intermediate run, do not limit economic activity and, therefore, need not be incorporated in the economic theory. The other holds that thermodynamics tells us that there are practical limits to materials recycling, which already puts bounds on the economy and, therefore, must be included in the economic models. Using the thermodynamic concept of entropy, we show here that there are fundamental problems with both positions. Even in the long run, entropy production associated with material dissipation need not be a limiting factor for economic development. Abundant energy resources from solar radiation may be used to recover dissipated elements. With simple, quantitative analysis we show that the rate of entropy production caused by human economic activities is very small compared to the continuous natural entropy production in the atmosphere and on the Earth's surface. Further, the societal entropy production is well within the range of natural variation. It is possible to replace part of the natural entropy production with societal entropy production by making use of solar energy. Society consumes resources otherwise available for coming generations. However, future generations need not have less resources available to them than the present generation. Human industrial activities could be transformed into a sustainable system where the more abundant elements are industrially used and recycled, using solar energy as the driving resource. An economic theory, fit to guide industrial society in that development, must not disregard thermodynamics nor must it overstate the consequences of the laws of thermodynamics.
... The shape of a future resource accounting system is gradually emerging, in response (partly, at least) to new perspectives introduced by ecological economics and industrial ecology. The first wave, inspired by the `energy crisis' of 1973-74 was a brief flurry of interest in `net energy' accounting in the late 1970s and early 1980s [Herendeen and Bullard 1974;Slesser 1975;Herendeen et al 1979;Herendeen 1998]; [Slesser 1977]; [Bullard et al 1978]; [Spreng 1988]. While not directly applicable to resource accounting, net energy analysis stimulated interest in a unit that reflects the usefulness (or quality) of mass. ...
There is an attractive analogy between nature and industry, based on the similarity of natural functions and certain industrial activities. For instance, animals ingest (eat) and digest food. Finally, there are metabolic wastes. Firms are analogous to organisms in several respects, insofar as they consume material resources, process (digest) them and produce output products and excrete wastes. Firms, like organisms, also compete with each other for resources. Curiously enough, one of the apparent differences between natural and man-made systems is actually not one; like the industrial system, the natural system does not recycle everything.
... (Hannon, 1973;Finn, 1976Finn, , 1980Patten et al., 1990). Indirect effects are especially important in the question of net energy: how the energy produced by an energy technology compares with the energy required to produce its inputs (Chapman, 1975;Chambers et al., 1979;Herendeen et al., 1979;Herendeen, 1988). ...
Similarities and differences between energy analysis and EMERGY analysis are discussed and highlighted using the two approaches to analyze the same systems. With particular emphasis on accounting schemes, parallel quantitative analyses of several simple model systems are performed. For the first time in the open literature EMERGY accounting procedures are given in detail. The discussion is presented in alternating sections since the authors still disagree on several fundamental issues.
This paper focuses on power generation systems and reviews the analytic method of LCA from past to present. Noted results of life cycle CO2 emissions (LCCO2) and some problems in evaluating LCCO2 are shown for grid power, renewable energy power and dispersed power. Net energy ratio, the ratio of the total energy production to the input energy except fuels, was an important index that shows how efficient the power generation technology is. Net energy ratio, however, was replaced with LCCO2 with the growing interest in global warming and the spread of LCA. Authorized results are known regarding LCCO2 of grid power and main renewable energy power. On the other hand, there remain some difficult problems regarding LCCO2 of dispersed power utilizing hydrogen or biomass in terms of data acquisition and evaluation method.
Außerhalb der Erde läßt sich ein wesentlich höherer Anteil der Sonnenenergie einfangen, da man hier außerhalb des Erdschattens und außerhalb der absorbierenden Luftschicht ist.
Net energy is intuitively compelling and useful in calculating total impacts (e.g., primary energy, greenhouse gases, land use, and water requirements.) of delivering useful energy to the larger economy. However, it has little policy impact unless connected quantitatively to the price of energy and other goods and services. I present an input-output (IO)-based method to do this. The method is illustrated by a two-sector model fitted to U.S. IO economic data. In an IO-characterized system, the energy returned on energy invested (EROI) and the energy intensity of energy are directly related. However, EROI and prices are not uniquely related because they depend differently on four independent IO coefficients representing internal structure of, and the relationship between, the energy sector and the rest of the economy. If only one of these coefficients varies, then EROI does uniquely determine prices. Uncertainties in the IO coefficients, as well as persistent issues of choosing system boundary and aggregating diverse energy types, further complicate the EROI-price connection. In this context I review two recent empirical comparisons of U.S. oil and gas prices and EROI for 1954-2007.
The goal of net energy analysis is to assess the amount of useful energy delivered by an
energy system, net of the energy costs of delivery. The standard technique of aggregating
energy inputs and outputs by their thermal equivalents diminishes the ability of energy
analysis to achieve that goal because different types of energy have different abilities to do
work per heat equivalent. This paper describes physical and economic methods of calculating
energy quality, and incorporates economic estimates of quality in the analysis of the
energy return on investment (EROI) for the extraction of coal and petroleum resources in
the U.S. from 1954 to 1987. EROI is the ratio of energy delivered to energy used in the
delivery process. The quality-adjusted EROI is used to answer the following questions: (1)
are coal and petroleum resources becoming more scarce in the U.S.?, (2) is society’s
capability of doing useful economic work changing?, and (3) is society’s allocation of energy
between the extraction of coal and petroleum optimal? The results indicate that petroleum
and coal became more scarce in the 1970s although the degree of scarcity depends on the
type of quality factor used. The quality-adjusted EROI shed light on the coal-petroleum
paradox: when energy inputs and outputs are measured in thermal equivalents, coal
extraction has a much larger EROI than petroleum. The adjustment for energy quality
reduces substantially the difference between the two fuels. The results also suggest that
when corrections are made for energy quality, society’s allocation of energy between coal
and petroleum extraction meets the efficiency criteria described by neoclassical and biophysical
economists.
An energy system model is presented which allows the analysis of net energy production or net power for a time-varying energy system. The model yields quantitative relations between the net power and such system parameters as energy cost, construction and lifetimes of individual plants, and overall power-growth rate. The model is applied to the substitution problem, and the net power output is analysed for transitions between systems with different energy costs.
The net energy ratios of most small-scale (≤ 25 MWe) hydroelectric demonstration projects are in the range of 10 to 12:1. This ratio compares quite favorably with ratios for thirteen other electric technologies. Of the eight nonelectric technologies summarized, natural gas systems yield the most net energy and systems producing alcohol from crops yield the least.
We have applied standard energy analysis to 4 types of geothermal-electric technologies: liquid dominated, hot dry rock, geopressure, and vapor dominated. We find that all are net energy producers, i.e. they have an energy ratio exceeding unity, where (excluding geothermal energy itself)Expected uncertainties are not large enough to threaten this conclusion. Vapor dominated, the only technology in current commercial use to produce electricity in the U.S. has the highest energy ratio (13 ± 4). These results for energy ratio are equal to or less than those obtained by workers. In the case of liquid dominated systems, this result is caused by the considerable energy requirement of pollution control technology.
Adult honeybees, confined singly or in small clusters, were exposed for 0.5, 6, and 24 hours to 2.45-GHz continuous wave microwave radiation at power densities of 3, 6, 12, 25, and 50 mW/cm2. Following exposure, bees were held in the incubator for 21 days to determine the consumption of sucrose syrup and to observe mortality. No significant differences were found between microwave-treated and sham-treated or control bees.
This paper deals with ongoing research work concerning energy budget and cost of the solar Satellite Power System (SPS).The fundamental model of such a total system including ground and space facilities, transportation vehicles, power satellites and rectennas is presented. The main purpose of this model is to examine the applicability of different construction scenarios to allow comparison under nearly identical constraints.Using this model in a first attempt the blankets—meaning the main part of the space segment by weight, energy investment needs and cost—are chosen representatively for the energy and cost comparison of two construction alternatives of the same SPS concept. These construction alternatives are defined just by ground and space based manufacturing of the solar blankets, while all other subsystems, operations and the transportation profiles are considered to be kept the same.It can be shown that the energy “payback” time does not only depend on the SPS concept selected but also very much on the construction and implementation scenario. The cost comparison of these alternative approaches presents not very significant differences but advantages for the space manufacturing option with potential higher differences for a less conservative approach which may apply benefits of space manufacturing meaning, for example, considerable mass savings in space.Some preliminary results are discussed and an outlook is given over the next steps to be investigated, comprising the extension of the fundamental model to include use of lunar raw materials.
This resource letter provides a source of information about the main types of solar energy and their uses, updating Resource Letter SE-1 issued seven years ago. It is intended for the use of high school and college teachers both in developing courses and in guiding students to the literature of solar energy applications. Articles marked with an asterisk have been selected for publication in an accompanying reprint book. The letter E after the reference number denotes a relatively elementary item, useful for high school and introductory college use and the educated public; the letter I denotes intermediate level references, sophomore to senior level; and the letter A denotes advanced material, principally for senior and graduate-level courses.
Energy inputs are compared with biomass energy output for several sawtimber and woody biomass programs covering rotation ages from 2 to 120 yr. A consistent comparision with several published studies supports the hypothesis that the energy ratio ER (i.e. the ratio of energy out to energy in) increases with increasing rotation age. For example, ER without fertilization and artificial drying increases from about 10–23 at rotation ages <15 yr to 42–46 at rotation ages >30 yr. Furthermore, it is shown that large changes in ER often produce negligible changes in the ratio of net-to-gross energy . Without fertilization and artificial drying, is always >0.87. However, if fertilization and artificial drying are used, may be as low as 0.60.
Net energy analyses have been carried out for eight trajectories which convert an energy source into heated domestic water. In addition, economic and metals consumed estimates have been made for three methods of producing heated domestic water. While some of the trajectories producing electrically heated water showed a slightly higher ratio of energy produced to energy consumed than a flat plate solar collector system, when all factors were considered (i.e. cost, quality of energy, and metals consumed), the flat plate solar collector system appears to be the system our energy policy should encourage for heating domestic water, even in the cloudy inter-Lakes area of the United States. Based on only net energy factors, it seems clear that the synthetic fuels program should not be encouraged as a means of providing a fuel source for heating domestic water.
A survey of the literature dealing with energy, health, and the environment sums up the various adverse effects of nuclear power, coal mining and utilization, oil shale systems, tar sands, geothermal cycles, nuclear fusion, and solar schemes. Several sources of harmful exposure are common to all of these energy alternatives: resource extraction, milling and processing, construction and operation of the energy-producing unit, and environmental pollution. Although no system is innocuous, solar and fusion projects have less potential for adverse impacts than do nuclear fission and synthetic fuels. As oil and natural gas sources become depleted, government, industry, and the public should assess the alternative energy sources in terms of health risks and environmental pollution as well as economic viability. Moreover, lessons learned in the past regarding occupational hazards (as in coal and uranium mining, for example) might be applied to the emerging oil shale and coal conversion technologies.
A series of hypotheses is presented about the relation of national energy use to national economic activity (both time series
and cross-sectional) which offer a different perspective from standard economics for the assessment of historical and current
economic events. The analysis incorporates nearly 100 years of time series data and 3 years of cross-sectional data on 87
sectors of the United States economy. Gross national product, labor productivity, and price levels are all correlated closely
with various aspects of energy use, and these correlations are improved when corrections are made for energy quality. A large
portion of the apparent increase in U.S. energy efficiency has been due to our ability to expand the relative use of high-quality
fuels such as petroleum and electricity, and also to relative shifts in fuel use between sectors of the economy. The concept
of energy return on investment is introduced as a major driving force in our economy, and data are provided which show a marked
decline in energy return on investment for all our principal fuels in recent decades. Future economic growth will depend largely
on the net energy yield of alternative fuel sources, and some standard economic models may need to be modified to account
for the biophysical constraints on human economic activity.
A model integrating economic and energetic concepts bridges the gap between the natural and social scientists in evaluating the effects of an interface between dispersed energy technologies and auxiliary power systems. The limitations and usefulness of each approach alone are examined and found to be a precise guide to policy when combined because external consideration must be given to national security and the environment. The viability of dispersed systems and their cumulative impact on electricity demand will be a significant part of policy and utility rate debates, and will need to be decided on an individual basis. Research should focus on the application of dispersed systems as supplemental to, rather than replacements for, conventional systems. 43 references, 1 figure, 2 tables. (DCK)
I review metabolic sources of reductant and ATP used by nitrogenase for all known classes of metabolism occurring among N2-fixing organisms. The discussion centers on free-living organisms preferentially over symbionts. I quantify the amounts of substrate required and convert these to free-energy efficiencies; anaerobes are seen as efficient in this sense. I clarify some thermodynamics of intermediate reactions, especially the need for ATP and the ability of NAD(P)H to reduce nitrogenase through ferredoxin. Three more contributions to net energy costs can be quantified: capital synthesis, assimilation and maintenance (two types). Several distinct loss routes for reactants and products exist, and I quantify their impacts. From net energy costs I calculate the decreases in substrate yields and increases in generation times. I review measurements of costs via these impacts in vitro and in vivo and discuss the orgins and amounts of variations due to important environmental conditions. The need for control of fixation by combined nitrogen, oxygen, and temperature is evident, but assessing its optimality requires critical definition and experimentation. The energy-intensiveness of fixation, especially relative to other sources of fixed nitrogen, has many specific consequences for ecological competitiveness of fixers. In whole-ecosystem function, a shared failure of metabolic strategies may exist, reducing the supportable biomass. In exploitation by humans via field crops and contained culture, ultimate consequences include restriction of the economic niche for biological fixation relative to current abiological alternatives such as chemical fertilizers. Lastly, I review the status of experimental studies of varied aspects of energetics and point out many opportunities for specific studies.
An examination of the potential yields and the capital costs of alternative or renewable energy sources leads to the tentative conclusion that at best these might jointly yield about half of present world energy consumption. The implications for the use of coal and nuclear energy are briefly noted. Conservation and improved efficiency are not regarded as being capable of solving the problem. It is suggested that alternative energy sources are sufficient to provide all people with reasonable living standards but that this would only be possible in a society with quite different values and economic structures to those now predominant.
Life cycle analysis (LCA) is an increasingly important tool for environmental policy, and even for industry. Analysts are also interested in forecasting future materials/energy fluxes on regional and global scales, as a function of various economic growth and regulatory scenarios. A fundamental tenet of LCA is that every material product must eventually become a waste. To choose the ‘greener’ of two products or policies it is necessary to take into account its environmental impacts from ‘cradle to grave’. This includes not only indirect inputs to the production process, and associated wastes and emissions, but also the future (downstream) fate of a product. The first stage in the analysis is quantitative comparisons of materials flows and transformations. Energy fluxes are important insofar as they involve materials (e.g., fuels, combustion products). This can be an extremely valuable exercise, if done carefully. However, the data required to accomplish this first step are not normally available from published sources. Theoretical process descriptions from open sources may not correspond to actual practice. Moreover, so-called ‘confidential’ data are unverifiable (by definition) and may well be erroneous. In the absence of a formal materials balance accounting system, such errors may not be detected. A key thesis of this paper is that process data can, in many cases, be synthesized, using models based on the laws of thermodynamics and chemistry. While synthetic but possible data may not fully reflect the actual situation, it is far superior to ‘impossible’ data. Most of the recent literature on LCA focusses on the second stage of the analysis, namely the selection and evaluation of different, non-comparable environmental impacts (‘chalk vs. cheese’). This problem is, indeed, very difficult-and may well be impossible to solve convincingly -even at the conceptual level. However, the only approach that can make progress is one that utilizes monetization to the limits of its applicability, rather than one that seeks to by-pass (or ‘re-invent’) economics. Nevertheless, the evaluation problem is second in priority, for the simple reason that LCA has utility even if the evaluation technique is imperfect. On the other hand, LCA has no (or even negative) utility if the underlying physical data is wrong with respect to critical pollutants.
Post treatment brood development was normal and teratological effects were not detected at exposures of 3 to 50 mw sq cm for 30 minutes. Post treatment survival, longevity, orientation, navigation, and memory of adult bees were also normal after exposures of 3 to 50 mw sq cm for 30 minutes. Post treatment longevity of confined bees in the laboratory was normal after exposures of 3 to 50 mw sq cm for 24 hours. Thermoregulation of brood nest, foraging activity, brood rearing, and social interaction were not affected by chronic exposure to 1 mw sq cm during 28 days. In dynamic behavioral bioassays the frequency of entry and duration of activity of unrestrained, foraging adult bees was identical in microwave exposed areas versus control areas.
The energy required to build and install solar space- and water-heating equipment is compared to the energy it saves under
two solar growth paths corresponding to high and low rates of implementation projected by the Domestic Policy Review of Solar
Energy. For the rapid growth case, the cumulative energy invested to the year 2000 is calculated to be ½ to 1½ times the amount
saved. An impact of rapid solar heating implementation is to shift energy demand from premium heating fuels (natural gas and
oil) to coal and nuclear power use in the industries that provide materials for solar equipment.
It is pointed out that a space manufacturing facility may be economically more effective than alternative industries on the earth for the construction of products which are to be used in geosynchronous or higher orbits. The suggestion is made to construct solar power stations at a space colony and relocate them in geosynchronous orbit to supply energy to the earth. Attention is given to energy problems and approaches for solving them, taking into account environmental effects and economic factors. Economic aspects of space manufacturing are discussed in some detail.
The appropriate role of satellite power station research and development
in ERDA's overall program is reviewed. A task group requested the
support to consist of (1) consolidating the relevant documentation; (2)
providing summary descriptions of the major systems and subsystems; (3)
delineating the status of key technologies; (4) preparing brief
summaries of the key economic and environmental issues; and (5)
assisting the task group in preparation of specified documentation.
Supporting efforts are also investigated.
A methodology is developed to compute the total energy requirements for electricity-generating systems using an input-output model that explicitly accounts for the physical flow of energy. The capital and operating requirements of 16 separate energy supply facilities are used to evaluate the total energy required by 9 alternative means of producing and delivering electricity. Evaluated electricity-generating systems rely on either fossil or nuclear energy as their fuel source. Energy payback periods are computed based on an equivalent electricity basis. These results are compared to a number of alternative capital investments to reduce energy demand. In general, the conservation options return their energy requirements sooner than the supply alternatives.
Responding to the controversy stirred by the initial papers analysing nuclear power, the author has refined the original analysis, correcting its ommissions, and aims to document the factual basis on which energy analysis of nuclear power is based. He concludes that differences in opinion on this application of energy analysis are due not simply to differences in data or the adoption of different analytical conventions, but rest upon fundamentally conflicting views of consumer behaviour and how energy is used.
Energy analysis has assumed an apparent major importance in the planning of energy use. The authors argue that debates over the detailed aspects of energy analysis and its applications are misplaced in face of the absence of any real assessment of the purpose of energy analysis. They offer the view that energy analysis fails to achieve its stated purposes and that economic analysis already provides a rational base for planning energy use, making energy analysis either superfluous or misleading.
In the energy filled there are many choices, conflicts, constraints and opportunities. While the author admits that net energy analysis has never claimed relevance to most of these issues, he asserts that the component to which it does address itself — the indirect inputs of energy to supply technologies — is relatively insignificant. It is within the noise level of near, let alone long term, judgements and uncertainty. Though analyses might have some value in checking the ‘net returns’ of very rapid and large technological shifts, eg insulation or nuclear programmes, to date they have not identified any significant effects when the whole energy system is taken into account. Finally, he concludes that the methods of net energy analysis contain several flaws which are not easily mended and which put at low confidence level on results. Net energy analysis is a red herring.
First developed for economic analysis, static linear input-output analysis has been adapted to deal with energy. This paper uses as a data-base the 1967 results of the input-output analysis of the US economy carried out every five years by the US Department of Commerce. In the 357 sector breakdown of the US economy there are five energy sectors, coal, crude oil and gas wells, refined petroleum, electricity and gas utilities. The model is used to determine the primary energy inputs to all sectors, taking account of the fact that energy is sold at different prices to different customers. Possible uncertainties in the model and updating methods are discussed.
Solar proton flare effects on silicon photovoltaic power system for deep space missions
Public and private decision makers are increasingly confronted with more complex and far-reaching public policy decisions concerning energy. Examples include responsible development of energy resources, allocation of energy research and development funds, legislated restrictions or subsidies for energy production and use, land use restrictions, and government regulation of major energy-producing industries. Decisions regarding all of these require analysis of the many social, economic, environmental, and political options and the delicate balancing of disparate yet competing interests, goals, and values. Various concepts regarding net energy analysis are reviewed and limitations on its usefulness for public policy decisions are evident. Congress has mandated the use of net energy analysis in assessment of new energy resources. Net energy analysis represents a marked departure from economic theory. In this paper, an assessment of the important assumptions and concepts underlying net energy analysis and a comparison of the different conclusions reached by net energy analysis and economic analysis are presented. The concepts of net energy and its important assumptions are defined; net energy analysis is subjected to an economic assessment; and some observations are made concerning the uses and limitations of the technique in the public policy-making process. (MCW)
Satellite Power Station White Paper on Resource Requirements
- A Kotin
Initial Comparative Assessment of Orbital and Terrestrial Central Power Systems JET PROPULSION LABORATORY FINAL REPORT
- Caputo R An
Independent Verification of I/O Energy Results Center for Advanced Computation Technical Memorandum
- K Kirkpatrick