RENEWABLE ENERGY SOURCES: THE CASE OF BRAZIL

Industrial nations have based their economic and social development on the use of fossil fuels (coal, petroleum and natural gas). This trend is being followed by many developing countries which have neither the natural resources nor the manpower to adopt this path. As a result one finds in many of these countries 'islands of prosperity' (based on consumption patterns copied from industrial nations) surrounded by a 'sea of poverty.' The problems resulting from this dual social structure are obvious in many parts of the world. It is argued here that renewable energy sources are a natural basis for the development of the poorer countries and that intelligent use of hydropower, biomass and direct solar energy can shortcut many of the problems faced today by industrial nations. The case of Brazil is analyzed as one of the countries in which these solutions are being tried.     

THE ECONOMICS OF RENEWABLE ENERGY SYSTEMS FOR DEVELOPING COUNTRIES

In many parts of the Third World, projects are being developed to test such renewable energy systems as biogas plants and solar cell arrays for powering pumps and grinders. Virtually nowhere, however, has adequate work been done to determine if these systems are worth their costs. This paper outlines the cost-benefit techniques which allow systems to be evaluated from the standpoint of individual buyers (financial analysis) and the society as a whole (economic analysis). Special attention is given to problems of particular importance in reviewing energy systems, including local measurement of costs and benefits, determination of investors' discount rates, shadow-pricing and allowance for social costs. Detailed cost-benefit analyses are provided for two representative systems: a family-scale Indian biogas plant and a 5.5 kW solar cell irrigation pump on the borders of Lake Chad. The family-scale biogas plant does not appear to be profitable in either financial or economic terms under any plausible sets of assumptions. The solar cell pump has positive net benefits by economic (if not financial) measures, but is unlikely soon to be competitive with diesel power for most applications. At best, some of these devices might ultimately become competitive with expensive commercial energy. Such devices will therefore be of interest first to people now using substantial amounts of such energy – that is, the relatively wealthy. Only much later might significant benefits begin to filter down to the poor. In the light of these findings renewed attention should be given to meeting basic energy needs through less sophisticated systems. By finding systems whose benefits are commensurate with their costs, and whose costs are within reach of the poor, it may be possible to provide more energy to those most in need of it. Dans de nombreuses parties du Tiers Monde, des projets sont en cours d'exécution en vue d'évaluer des systèmes en matière d'énergie de remplacement, tels que des usines de gaz de fermentation et des assemblages de cellules solaires pour activer pompes et broyeurs. Toutefois, il semblerait qu'il n'y ait eu nulle part aucune étude valable permettant de déterminer si ces systèmes justifient leur coût. Cet article relève les techniques de coût-utilité qui permettent d'évaluer ces systèmes du point de vue des acheteurs individuels (analyse financière) et de la société dans son ensemble (analyse économique). En analysant ces systèmes, l'article souligne des problèmes d'importance particulière, y compris l'évaluation locale des coûts et profits, la détermination des taux d'actualisation d'investissement, l'estimation des prix virtuels et l'établissement de marges de coûts sociaux. Des analyses détaillées de coût-utilité sont présentées pour deux systèmes concrets: une usine de gaz de fermentation indienne à l'échelle de la famille, et une pompe d'irrigation à cellules solaires de 5,5 kW sur les rives du lac Chad. L'usine de gaz de fermentation à l'échelle de la famille ne semble ni financièrement, ni économiquement rentable quelque soient les termes plausibles des hypothèses. La pompe à cellules solaires offre des profits positifs nets selon des critères économiques (sinon financiers) mais, dans la plupart des cas, elle ne semble pas pouvoir concurrencer le moteur diesel dans un proche avenir. Au mieux, quelques-unes de ces installations peuvent à la longue concurrencer l'énergie commerciale à prix élevé. Par conséquent, elles seront d'intérêt particulier tout premièrement aux usagers de grande quantité de cette énergie, c'est-à-dire ceux possédant des moyens relativement élevés. Ce n'est que bien plus tard que les classes défavorisées pourront commencer à bénéficier sensiblement des profits qui en résulteront. Sur la base de ces données, les organisations s'intéressant aux classes défavorisées peuvent se pencher à nouveau sur la manière de répondre aux besoins essentiels en matière d'énergie en utilisant des systèmes plus simples: bois appartenant aux villages, fours à bois améliorés, pompes et broyeurs à pédales ou à bras, pompes foulantes hydrauliques, etc. En conçevant des systèmes dont les profits sont proportionnels aux coûts et dont les coûts sont à la portée des classes défavorisées, il se peut que l'on puisse mettre plus d'énergie à la disposition de ceux qui en ont le plus besoin. En muchas partes del Tercer Mundo se han llevado a cabo proyectos para ensayar sistemas de energía renovables tales como plantas de biogas, y celdas solares para operar bombas y molinos. Sin embargo practicamente en ninguna parte se ha hecho el esfuerzo apropiado para determinar si estos sistemas valen lo que cuestan. Este artículo esboza las técnicas de beneficio-costo para evaluar dichos sistemas desde el punto de vista del usuario individual (análisis financiero) y del de la sociedad como un todo (análisis económico). Se da especial atención a los problemas de importancia particular en el análisis de sistemas de energía, incluyendo mediciónes locales de costos y beneficios, determinación de la tasa de descuento del inversionista, precios-sombra y costos sociales. Detallados análisis de beneficio-costo se proveen para dos sistemas representativos: una planta de biogas en escala familiar y una bomba de agua operada por celadas solares de 5.5 kW al borde del Lago Chad. La planta de biogas a escala familiar parece no ser rentable financieramente ni económicamente bajo ninguna serie de hipótesis realistas. La bomba de celdas solares tiene un benefico económico positivo (aunque no financiero), pero es poco provable que sea competitivo con el motor diesel para la mayoría de las aplicaciones. En el mejor de los casos, alguno de estos sistemas pueden ser competitivos con una energía comercial cara. Estos sistemas en consecuencia serán de gran interés primeramente para las personas que hacen uso intensivo de energía, esto es, las personas relativamente adineradas. Pueda qui solo mucho despues beneficios significativos lleguen a los pobres. A la luz de estos resultados debe ponerse renovada atención a satisfacer las necesidades básicas de energía a través de sistemas menos sofisticados. Pueda que sea posible proveer mas energía a los que más necesitan de ella si se buscan sistemas cuyo beneficios sea proporcionados a sus costos y que dichos costos esten al alcance de los pobres.     

ECONOMIC CONSIDERATIONS FOR SOLAR AND RENEWABLE ENERGY IN DEVELOPING COUNTRIES

High costs of all commercial (especially imported) fuels have had especially severe impacts on the developing nations and, within these, on the most disadvantaged regions and socio-economic groups. Improving the security of supply while stabilizing prices has become a major energy-economic need. For the less developed nations this particularly calls for greater indigenous energy production and improved regional supply without massive capital commitments. Solar and renewable sources have a critical part to play in this. Certain of these appear promising for immediate development. For the longer term their potentials are far greater — but economic acceptance requires changed evaluation methods. Les pays en développement, et parmi eux les régions et groupes socioéconomiques les plus défavorisés, ont fortement ressenti les incidences particulièrement graves de la hausse des prix des combustibles commerciaux (et plus spécialement, des combustibles importés). S'assurer plus attentivement de l'approvisionnement tout en contenant le niveau des prix est devenu un impératif de leur politique énergético-économique. En ce qui concerne ces pays, cet effort requiert en particulier une production plus abondante d'énergie locale et une amélioration des approvisionnements régionaux sans engagements de capitaux démesurés. Les sources d'énergie solaire et d'énergie de remplacement ont un rôle significatif à jouer dans ce domaine. Quelques-unes d'entre elles destinées à certaines utilisations semblent pouvoir être mises en valeur dans l'immédiat. A longue échéance, leur potentiel est encore d'une plus grande portée. Cependant, pour les rendre rentables, leur méthodes d'évaluation serait à repenser. El alto costo de los combustibles (especialmente los importados) ha tenido un impacto especialmente severo en los paises en desarrollo, particularmente en las regiones y los grupos socioeconómicos que se encuentran en situación desventajosa. Mejorar la seguridad del suministro procurando al mismo tiempo mantener los precios estables se ha convertido en una necesidad importante dentro de la economía de la energía. Para los paises menos desarrollados esto significa especialmente desarrollar recursos energéticos propios y mejorar el suministro regional sin comprometer capital en forma masiva. Los recursos renovables (energiá solar) tienen un rol de importancia crítica y algunos de ellos parecen promisorios para su desarrollo immediato. Para el largo plazo el potencial de estos recursos es mucho mas grande aún — pero su aceptación económica requiere todos de evaluación nuevos.     

IMPACT OF THERMAL STANDARDS ON POWER PLANT WATER CONSUMPTION1

Power plant water consumption (evaporative water loss) for various river temperature standards is presented for existing and proposed power plants located along the Missouri and Upper Mississippi Rivers in the MAPP geographical area. Thermodynamic and economic models are combined to evaluate the cooling related water consumption at various river thermal standards. The existing thermal standards and a number of other hypothetical thermal regulations including the extreme cases of no thermal standards and no allowable heated discharges are examined to show the dependence on thermal standards of power production related water consumption. A critical appraisal of the cost of thermal standards in terms of water consumption is thereby possible so that subjective assessments of the standards can proceed with full knowledge of the tradeoffs involved between the “water costs” of power production and environmental enhancement.     

REGULATORY REQUIREMENTS AFFECTING AQUIFER THERMAL ENERGY STORAGE1

ABSTRACT: Thermal energy storage involves the capture and storage of thermal energy (either heat or chill) during one time period for use at a later period. Storage of thermal energy in aquifers on a seasonal basis is one promising application of the technology that has been implemented in several foreign countries and is currently undergoing field testing in the U.S. Potential developers of aquifer thermal energy storage projects will face a number of regulatory requirements at the federal, state, and local level of government. These can include meeting: (1) surface land and ground water use restrictions, (2) regulations relating to withdrawal of ground water, and (3) requirements for reinjecting thermally altered ground waters. Separate permits for ground water withdrawal and reinjection may be required. The permit process is likely to involve opportunities for public comment and may involve contested proceedings.     

JAMAICA - A CASE STUDY OF ENERGY PLANNING

The analysis shows the impact of the 'New International Energy Order' on Jamaica, a developing country almost totally dependent on imported oil for satisfying national energy demand. The energy supply/demand situation between 1961 and 1976 and the structure of energy consumption by major sectors of the economy are discussed. The high income elasticity of commercial energy demand and the increase in the energy intensity of the economy is directly related to expansion of the alumina industry. The structural problems of decoupling GDP and energy growth are indicated. In particular, the impact of the 'New Energy Order' on the development prospects of major bauxite/alumina producing countries which are deficient in indigenous primary energy resources is assessed. Finally, the indigenous resource base is outlined and the major elements of the five-year (1978–1982) national energy plan summarized.     

ADMINISTRATION OF GROUND WATER AS BOTH A RENEWABLE AND NONRENEWABLE RESOURCE1

ABSTRACT: Ground water is intended to be administered in many western states as a flow or renewable resource. In Idaho, this administration is based on the appropriation doctrine of water rights. Two generalizations may be made concerning ground water. First, water artificially discharged from an aquifer system must deplete the total resource by that amount; water consumptively pumped from a well must be derived from either increased recharge, decreased discharge or a decrease of water in storage. Second, the annual rate of recharge to a ground-water system is often only a small percentage of the total resource in storage. Ground water may be divided into flow and stock portions. In those basins where the second generalization is true, most ground water may be classified as stock. However, only the flow portion of ground water may be developed if utilization of the resource is to be enjoyed over an infinite period. Data from the Raft River Basin in Idaho indicate that the flow and stock characteristics of ground water are time dependent. The resource exhibits the characteristics of both a renewable and nonrenewable resource. As a result, present administrative techniques do not provide for effective management of the resource.     

A GROUND WATER RESOURCES STUDY OF A PACIFIC OCEAN ATOLL - TARAWA,GILBERT ISLANDS1

ABSTRACT: The geology and fresh ground water lens development in a typical Pacific atoll are described together with a method for hydrogeological investigation. The fresh water resources of such lenses are investigated using Tarawa as an example. It is shown that simple steady state solutions cannot be realistically applied, and that despite the paucity of hydrogeological data, which is considered typical of such islands, practical nonsteady state solutions allow resource assessments. The susceptability of lens resources to drought conditions is demonstrated.     

THE ECONOMICS OF GEOTHERMAL POWER

This article, based on a rapporteur's report, is a synthesis of papers read before the United Nations Symposium on the Development and Utilization of Geothermal Resources, held at Pisa, Italy, in 1970. It covers a broad cross-section of experience in exploiting geothermal energy, especially in Hungary, Iceland, Italy, Japan, New Zealand, the Union of Soviet Socialist Republics and the United States of America     

THE ECONOMICS OF GEOTHERMAL POWER

This article, based on a rapporteur's report, is a synthesis of papers read before the United Nations Symposium on the Development and Utilization of Geothermal Resources, held at Pisa, Italy, in 1970. It covers a broad cross-section of experience in exploiting geothermal energy, especially in Hungary, Iceland, Italy, Japan, New Zealand, the Union of Soviet Socialist Republics and the United States of America     

SIMULATION OF URBAN NON-POINT SOURCE POLLUTION1

ABSTRACT: Public Law 92–00 has mandated the need for evaluating the impact of nonpoint source pollution on receiving water quality, primarily through Section 208 Areawide Planning. The Management of Urban Non-Point Pollution (MUNP) model was developed to estimate the accumulation of eight non-point pollutants on urban streets, their removal by both rainfall and street sweeping operations. The model can simulate the following pollutants: total solids or sediment-like material, volatile solids, five-day biochemical oxygen demand, chemical oxygen demand, Kjeldahl nitrogen, nitrates, phosphates, and total heavy metals. The simulated results can be used for investigation of non-point pollution management alternatives. The model is capable of reflecting variation in such diverse factors as physical and chemical characteristics of accumulated pollutants, land use characteristics, rainfall characteristics, street sweeper characteristics, roadway characteristics, and traffic conditions. By using mean estimates of many input variables for large segments of a city, the MUNP model could be used to quickly assess the magnitude of pollutants annually entering receiving waterways due to nonpoint source pollution alone. If the results indicate that non-point pollution loadings are sizeable and require futher analysis, the MUNP model could be used to define the specific nonpoint source pollution areas within a city. Hypothetical locations and actual rainfall data for Washigton D.C. were used to demonstrate some capabilities of the MUNP model.     

COMPARISON OF THERMAL SCANNING AND IN SITU TECHNIQUES FOR MONITORING THERMAL DISCHARGES1

ABSTRACT: In situ and remote sensing techniques for measuring thermal plumes are compared for data taken at the Point Beach Nuclear Power Plant on Lake Michigan for five separate occasions. The in situ method employed a boat whose position was determined with a microwave ranging system. Temperatures at the surface and at various depths were measured with fast response thermistor probes. The remote sensing technique utilized an infrared scanner in the 8 to 14 micron range. Comparison of the plumes indicates good agreement with respect to plume configurations, areas within isotherms and centerline temperature decays for all except one occasion, a calm day characterized by no waves, low wind and ambient current velocities. Robable reasons for disagreement under such ambient conditions are discussed. The inherent advantages and disadvantages of each method are discussed in light of the results of the five sets of data. This includes both the data collecting and data analyzing procedures. It is concluded that judicious combination of both methods offers a better picture of thermal plumes than can be obtained by either technique alone.     

ENERGY SOURCES IN CHINA - PRESENT AND FUTURE

In 1979 China produced 640 million tons coal equivalent (TCE) of energy. Although this was sufficient to meet its demand of 586 million TCE in 1979, the Chinese Government is anticipating a difficult struggle for energy self-sufficiency in the next few years as demand increases rapidly owing to modernization efforts in the Chinese economy. The exploitation of coal will have highest priority in the Chinese energy development plan, followed by hydroelectricity. Petroleum and natural gas will be used mainly as raw materials for the chemical industry and as fuel for internal combustion engines. The institution of conservation measures coupled with necessary adjustments in the economic and industrial structures will also be given special attention in the energy plan. New and renewable resources of energy such as biomass, solar, wind, tidal wave and geothermal energies have played important roles in the various regions of the country where conditions are favourable and will continue to be developed. Nuclear energy will also be developed in industrially developed areas with acute shortages of power. Overall, it is projected that in the next twenty years the production of conventional energy must be doubled in order to satisfy the increasing demand. Capital resources remain the principal obstacle in such efforts. China will need external financial assistance, in the form of joint ventures, compensation trade or long-term loans to develop the abundant but relatively unexploited energy resources. En 1979, la quantité d'énergie produite en Chine représentait 640 millions de tonnes-équivalent charbon (tec). Bien cette quantité fut suffisante pour répondre à une demande de 586 millions de tec en 1979, le Gouvernement de la Chine anticipe une lutte soutenue pour arriver à une auto-suffisance en matière d énergie dans les quelques prochaines années alors que la demande augmente rapidement dû aux efforts de modernisation de l'économie chinoise. Dans le plan énergétique de la Chine, l'expoitation du charbon gardera une place de premier plan suivi de l'hydro-électricité. Le pétrole et le gaz naturel seront employés principalement comme matières premières dans l'industrie chimique et comme carburant pour les engins à combustion interne. Une attention particulière sera accordée dans le plan énergétique à l'institution de mesures de conservation, alliées aux ajustements nécessaires dans les structures économiques et industrielles. Les sources d'énergie nouvelles et renouvelables, telles que la biomasse, les énergies solaire, éolienne, marémotrice et géothermique ont joué des rôles importants dans de nombreuses régions du pays où les conditions sont favorables et continueront à être mises en valeur. L'utilisation de l'énergie nuclèaire sera aussi intensifiée dans les régions industriellement développées dans lesquelles se fait sentir de manière aiguë la penurie d'énergie électrique. Dans l'ensemble, on prévoit que dans les vingt prochaines années, la production conventionnelle d'énergie doit être doublée pour répondre à une demande droissante. Les capitaux demeurent un obstacle sérieux à ces efforts. La Chine aura besoin d'assistance financière extérieure sous forme d'associations en participation, d'échanges compensatoires, de prèts à long terme afin de mettre en valeur ses ressources énergétiques abondantes mais relativement inexploitées. En 1979 China produjo 640 millones de tonelades equivalentes de carbón que fue suficiente para satisfacer la demanda de energia de aquel año. Sin embargo el gobierno anticipa dificultades en mantener la autosuficiencia en energia en los próximos años debido al rápido aumento de la demanda causada por la modernización de la economía. Dentro del plan de desarrollo energético, la explotación del carbón tendrá la máxima prioridad seguido por la hidroelectricidad. El petróleo y el gas natural serán usados principalmente como insumo en la industria química y como combustible en los motores de combustión interna. Las medidas de conservación de energia y ajustes en la estructura de la industria y la economia en general recibirán especial atención. Los recursos nuevos y renovables han jugado un rol importante en varias regiones del país y conti nuarán siendos desarrollados. Le energia nuclear también se desarrollará en las áreas industriales que sufren carestia en electricidad. En general, se proyecta que en los próximos 20 años se doblará la producción de energia convencional para satisfacer la demanda creciente La falta de capital será la restricción principal para tal esfuerzo. China necesitará en consecuencia asistencia financiera externa en la forma de inversiones compartidas y préstamos a largo plazo para desarrollar los abundantes pero relativamente inexplotados recursos energéticos.     

THIRD WORLD ENERGY OPTIONS AND THE ROLE OF THE SOLAR ENERGY RESEARCH INSTITUTE

Developing countries are now in a position to choose between further commitments to petroleum and development of sustainable solar resources. Many solar options are ready and some are already economically competitive, particularly for use in rural areas where most people in developing countries reside. Third World countries are becoming cautious about imitating industrial nations, and in some cases, are beginning to map out unique strategies based on their indigenous cultures and resources. Transitions to solar technologies will not be made without difficulty, however, as baseline data on energy needs and on availability of renewable forms of energy only marginally exist. This paper presents information on the potential and current status of a range of solar technologies. The United States Solar Energy Research Institute (SERI) is advancing a number of technologies that will have direct impact on life in developing countries; but in addition has established a programme to deal specifically with the use of renewable energy resources in developing countries. Technical development, planning, information compilation, and institution building are fundamental parts of the effort. As a research institute, SERI, in particular, wants to ensure that adequate attention is given to the technical problems associated with the use of renewables in developing countries. Too often, these problems are not recognized as being worthy of scientific attention resulting in the design and installation of less than optimal equipment. The limited resources available require optimal allocation and intelligent application. In addition, SERI manages bilateral assistance programmes with developing countries under the auspices of the US Department of Energy and the US Agency for International Development. Les pays en développement ont maintenant la possibilité de choisir entre un système basé sur le pétrole ou la mise en valeur des ressources solaires potentielles. Plusieurs systèmes de récupération de l'énergie solaire sont utilisables et quelques-uns sont déjà économiquement compétitifs, particulièrement dans les régions rurales où se rencontre la majeure partie de la population des pays en développement. Les pays du Tiers Monde exercent de plus en plus une certaine prudence à imiter les pays industriels et, dans certains cas, commencent à formuler des stratégies basées uniquement sur leurs ressources et cultures propres. Cependant, le passage à l'énergie solaire ne se fera pas sans difficulté étant donné que les données de base sur les besoins énergétiques et sur la disponibilité des formes renouvelables d'énergie sont marginales. Cet article donne des informations sur le potentiel et l'état actuel de toute une gamme de technologies solaires. L'Institut de recherche d'énergie solaire (IRES) des Etats-Unis est en train de promouvoir un certain nombre de technologies qui auront une portée directe sur le mode de vie dans les pays en développement. II a aussi élaboré un programme spécial concernant l'utilisation des ressources énergétiques renouvelables dans les pays en développement. Le développement technique, la planification, le rassemblement de l'information et la mise en place d'institutions représentent des composantes fondamentales de cet effort. En tant qu'institut de recherche, IRES en particulier voudrait s'assurer que les problèmes techniques concernant l'utilisation des énergies renouvelables dans les pays en développement soient étudiés sérieusement. Trop souvent ces problèmes ne sont pas reconnus comme méritant une étude scientifique ce qui entraîne la conception et la construction d'un équipement qui n'est pas le meilleur. Les ressources disponibles étant limitées, elles requièrent une répartition optimale ainsi qu'une utilisation intelligente. De plus, IRES dirige des programmes d'assistance bilatérale avec les pays en développement sous les auspices du Département de l'énergie et de l'Agence pour le développement international des Etats-Unis. Los países en desarrollo están ahora en la posibilidad de escoger entre una mayor dependencia del petróleo y el desarrollo de energía solar. Muchas alternativas de uso de energía solar están disponibles y algunas son economicamente competitivas, especialmente en las zonas rurales donde reside la mayor parte de la población de los países en desarrollo. Los países del tercer mundo están mas cautos en imitar los países industrializados, y en algunos casos, están empezando a establecer estrategias basadas en su cultura autóctona y sus recursos. Sin embargo la transición a la tecnología solar no va a ser fácil puesto que la información básica sobre las necesidades de energía y la disponibilidad de recursos renovables es muy escasa. Este artículo examina el potencial y la situación actual de las tecnologías de aplicación de energía solar. En los Estados Unidos, el Instituto de Investigación de Energía Solar (IIES) esta proponiendo ciertas tecnologías que tendrán impacto directo sobre la vida en los países en desarrollo, adicionalmente ha establecido un programa para tratar especificamente el uso de recursos renovables de energía en países en desarrollo. Desarrollo técnico, planificación, procesamiento de información y organización de instituciones son partes fundamentales de este esfuerzo. EL IIES quiere asegurar que se dé adecuada atención a los problemas técnicos relacionados con el uso de recursos renovables en los países en desarrollo. A menudo estos problemas se consideran como no importantes para ser objeto de investigación científica y como resultado se diseñan e instalan equipos que no son óptimos. Sin embargo los recursos limitados requieren que se hagan asignaciones óptimas de recursos y aplicaciones inteligentes. Además, el IIES administra programas de asistencia bilateral con los países en desarrollo bajo los auspicios del Departamento de Energía y la Agencia para el Desarrollo Internacional de los Estados Unidos de América.     

CHEAP POWER - AN EXPENSIVE FAILURE: HYDRO-ELECTRIC POWER AND INDUSTRIAL DEVELOPMENT IN NEWFOUNDLAND1

ABSTRACT By creating the 459,000 kW Bay d'Espoir h.e.p. scheme, the Newfoundland government hoped that the consequent doubling of the island's electricity supply would not only eliminate a deficite situation but provide power for industrial development. These hopes have not been fulfilled, and only one company, producing elemental phosphorus, was attracted to the island by the government's ‘cheap power’ policy. In addition to the continuing power subidy, this company received considerable federal and provincial incentives by locating its plant in Newfoundland. To these direct financial costs have to be added the environmental destruction and deterioration stemming from the h.e.p. development and the haste with which its construction was undertaken, and the catastrophic pollution problem created by effluent from the phosphorus plant. The costs of the ‘cheap power’ policy have been, and continue to be, massive for Newfoundland, Canada's poorest province. Further, the policy has made little or no impact on the small job market and the very large unemployment problem.     

AN ANALYSIS OF ENERGY CONSUMPTION IN INDIA

This article analyses energy consumption in India. It explains the dynamics of the changes in energy flow by studying four different time periods between 1953 and 1976. Unlike earlier studies, which concentrated only on commercial fuels, this study attempts to develop an integrated source-sector flow model comprising both commercial and non-commercial fuels. The patterns of change in the energy flow are used to derive major macro-economic energy linkages for the country. The article also examines the relationship between energy consumption, economic growth and investment. Cet article analyse la consommation énergétique en Inde. Il étudie la dynamique des variations du flux d'énergie pendant quatre périodes différentes comprises entre 1953 et 1976. Contrairement à des études précédentes qui ne se sont occupées que des produits pétroliers commerciaux, cette étude tente de construire un modèle integrant la source d'énergie et le secteur de consommation à la fois des produits pétroliers commerciaux et non-commerciaux. Les variations du flux d'énergie sont utilisées pour mettre en évidence les principales relations macroéconomiques du secteur énergétique du pays. De plus, l'article étudie les rapports existant entre la consommation énergétique, la croissance économique et l'investissement. Este artículo analiza el consumo de energía en la India y explica la dinámica de los cambios en los flujos de energía al estudiar cuatro périodes diferentes entre 1953 y 1976. A diferencia de estudios anteriores que se concentran en combustibles comerciales, este estudio trata de desarrollar un modelo integrado que incluye combustibles comerciales y no comerciales. Las tendencias de los cambios en los flujos energéticos son usados para derivar las principales interrelaciones macroeconómicas en el país. El artículo examine también la relación entre consumo de energía, crecimiento económico e inversión.     

WORLD ENERGY RESOURCES - LIMITS FROM TODAY'S GEOLOGICAL STANDPOINT

World fossil energy resources are estimated at about 12,500 times 10⁹ tons of coal equivalent (t.c.e.) of which 900 times 10⁹ t.c.e. are classed as presently recoverable reserves. Future exploration will transform a substantial part of the resources into reserves. Coal is by far the dominant fossil energy. Oilshales and tarsands represent a large energy potential, whose utilization depends on a high energy price level and progress in production technologies. Limits in the availability of oil and gas are visible now for the first time. Low-cost, high-grade uranium reserves are also limited. However, there are large amounts of low-grade uranium resources, which might become recoverable in the future. The use of geothermal energy is currently troubled by problems of technology, costs and environment.     

NONPOINT SOURCE DISCHARGES OF NUTRIENTS FROM PIEDMONT WATERSHEDS OF CHESAPEAKE BAY1

ABSTRACT: We measured annual discharges of water, sediments, and nutrients from 10 watersheds with differing proportions of agricultural lands in the Piedmont physiographic province of the Chesapeake Bay drainage. Flow-weighted mean concentrations of total N, nitrate, and dissolved silicate in watershed discharges were correlated with the proportion of cropland in the watershed. In contrast, concentrations of P species did not correlate with cropland. Organic P and C correlated with the concentration of suspended particles, which differed among watersheds. Thus, the ratio of N:P:Si in discharges differed greatly among watersheds, potentially affecting N, P or Si limitation of phytoplankton growth in the receiving waters. Simple regression models of N discharge versus the percentage of cropland suggest that croplands discharge 29–42 kg N ha^-1 yr^-1 and other lands discharge 1.2–5.8 kg N ha^-1 yr^-1. We estimated net anthropogenic input of N to croplands and other lands using county level data on agriculture and N deposition from the atmosphere. For most of the study watersheds, N discharge amounted to less than half of the net anthropogenic N.     

MODELING OF NONPOINT SOURCE POLLUTION OF NITROGEN AT THE WATERSHED SCALE1

ABSTRACT: The Watershed Nutrient Transport and Transformation (NTT-Watershed) model is a physically based, energy-driven, multiple land use, distributed model that is capable of simulating water and nutrient transport in a watershed. The topographic features and subsurface properties of the watershed are refined into uniform, homogeneous square grids. The vertical discretization includes vegetation, overland flow, soil water redistribution and groundwater zones. The chemical submodel simulates the nitrogen dynamics in terrestrial and aquatic systems. Three chemical state variables are considered (NO₃^-_-, NH₄⁺, and Org-N). The NTT-Watershed model was used to simulate the fate and transport of nitrogen in the Muddy Brook watershed in Connecticut. The model was shown to be capable of capturing the hydrologic and portions of the nitrogen dynamics in the watershed. Watershed planners could use this model in developing strategies of best management practices that could result in maximizing the reductions of nitrogen export from a watershed.