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2. Energy installations and fuels - Environmental impacts and protective measures
3. Notes on the analysis and evaluation of environmental impacts
4. Interaction with other sectors
4.1 General development policy objectives and socio-economic/socio-cultural dimensions
4.2 Interaction with other sectors
5. Summary assessment of environmental relevance
The energy system of a country comprises all the components of primary production of energy (e.g. coal mining, oil production, collection of biomass in rural areas, energy imports), the entire conversion sector (production of secondary energy sources, e.g. manufacture of petroleum products from crude oil in refineries or generation of electricity in coal- or oil-fired power stations or using hydroelectric power, or the "refinement" of biomass, e.g. using charcoal kilns), the infrastructure necessary for distribution and storage of energy sources (e.g. tank farms, pipelines, power lines) and technologies for eventual energy use (e.g. motor vehicles, stoves, lamps, refrigerators etc.).
Fig. 1 - The energy system and its adverse environmental impacts
An energy system is an essential supply sector the principal purpose of which is to provide energy services (e.g. for cooking, lighting, air-conditioning, transport etc.). Energy systems are flexible within certain limits, i.e. the energy service desired can be provided by means of a number of different technologies based on different energy sources (e.g. electricity, petrol, coal etc.).
Because of its great significance for the functioning of a community and the long periods which sometimes elapse between the identification of a requirement, the investment decision and the commissioning of plants and networks, together with long-term impacts on the environment and on society, overall energy planning (OEP) assumes an important role as a coordinating tool.
The range of tasks covered by OEP includes clarification at local, regional and national level of when, where and how much of the various types of energy (electricity, fuels, heat etc.) has to be provided and what measures are necessary to satisfy demand (increasing requirement, demand forecast). Existing supply systems (fuels etc.) are investigated in terms of their financial, economic and ecological feasibility. This takes into account current and anticipated future general circumstances of the country in question, technological progress and probable changes in the world energy sector (looking ahead for 10 to 30 years). From analyses of various demand structures and potential ways of meeting demand it is possible to devise scenarios whereby energy-policy decisions, such as investments in power stations and networks, formulation of pricing policy (tariffs, charges, taxes, subsidies) and identification of environmentally acceptable supply routes in terms of their prerequisites and anticipated impacts can be opened up to public debate and compared. In this respect fair distribution of energy in regional and social terms is particularly important.
In the case of projects involving public utilities or state controlling authorities, general energy/economic statistics are of central importance in terms of the energy requirement of all areas of supply. Specific factors (preferences, consumption habits, ability to pay, costs, availability of energy) must be taken into account when dealing with sector-specific and regional sub-structures of the energy-producing industry, as is the case with special studies for trade, industry and for private households (plant designs, local and regional energy concepts). This also facilitates the development of so-called "tailor-made" solutions. Ideally findings in these subsidiary areas should be used to fine tune OEP at national level, to find solutions which improve not only the economy but also other aspects such as fairness of distribution.
National energy systems throughout the world vary widely:
- First of all, the structure of energy consumption varies. In some cases -with the exception of hydroelectric power - fossil fuels (e.g. coal, oil, gas) are used almost exclusively. Nuclear energy will be disregarded in what follows1). In some countries there is still very widespread use of biomass (firewood, agricultural residues, dung). Use of renewable energy sources such as solar and wind energy is still very limited. The structure and level of energy consumption frequently varies considerably from town to country.
1) In what follows the use of nuclear energy is disregarded because its environmental acceptability is still the subject of much controversy in industrialised countries and it is impossible to make a definitive assessment (particularly given problems of final storage of radioactive waste) and because it is used and/or considered for use in very few developing countries (particularly in view of stringent operating requirements and high investment costs).
- There are also wide differences in the level of energy consumption. High-income countries on average consume 230 GJ per head of population (USA 360 GJ, Germany 200 GJ), but the figure for medium-income countries is around 125 GJ and for low-income countries 25 GJ.
If we consider only those energy sources traded on world markets, the differences are even more extreme: per capita consumption in medium-income countries falls to around 15 GJ and in low-income countries to 4 GJ, i.e. only one 60th of consumption in high-income countries.
In many countries, future energy demand will develop along two different characteristic lines: (1) A growing population, rapid urbanisation, increasing industrialisation and mechanisation of agriculture will cause energy demand to grow more strongly. (2) Fossil fuels will account for a greater proportion of overall consumption in developing countries because certain energy services are directly dependent on them, and cheap, efficient alternatives are not available for the time being. For example, the use of petrol and diesel fuel will still be of major significance for road transport in future. Where adequate supplies of hydroelectric power are unavailable, countries will look to increased use of fossil fuels to meet growing electricity demand.
Energy planning must react to these needs, but can also analyse reported demand and take account of possible alternative forms of development.
2. Energy installations and fuels - Environmental impacts and protective measures
All forms of (man-made/industrial) energy supply and all uses of energy are environmentally detrimental and exert some degree of human impact. The nature and intensity of these impacts depend on the way in which the actual energy service is provided. Early consideration of the environmental impacts of the various energy systems (i.e. as early as the planning process) is advantageous for two reasons:
- Social priorities and probable impacts of various energy supply methods can be compared with one another. By looking at the costs and benefits of different supply methods or projects for different social groups - if possible with the involvement of the population groups affected - decisions can be made transparent.
- The avoidance or minimisation of environmental problems beforehand (preventive environmental conservation) is generally far more effective and economical than subsequent cleaning up or "rehabilitation" of a polluted and partly destroyed environment afterwards (reactive environmental protection).
The OEP in itself has no direct impact on the environment, but planning outcomes differ considerably in terms of their environmental relevance. Therefore at this point we merely refer to other environmental briefs in which the environmental impacts of energy installations for production, conversion and utilisation of various energy media are identified and evaluated:
- Rural Hydraulic Engineering
- Large-Scale Hydraulic Engineering, Dams and Weirs
- Surface Mining
- Underground Mining
- Minerals - Handling and Processing
- Thermal Power Stations
- Petroleum and Natural Gas - Exploration, Production, Handling, Storage
- Power Transmission and Distribution
- Coking Plants, Coal-to-Gas Plants, Gas Production and Distribution
- Renewable Sources of Energies.
3. Notes on the analysis and evaluation of environmental impacts
At all planning stages, OEP must take full account of the diverse impacts of the energy system on the environment. Planning must take account of the current situation of the country. The level and structure of energy consumption vary according to economic strength, availability of resources and geographical position; existing burdens on the different environmental media vary, and different forms of development are possible depending on technological and financial capacity.
For a realistic assessment of environmental loads generated by energy, the entire process chain must be examined from primary production of energy, including individual conversion stages and actual energy use by the "consumer", right through to disposal of waste and residual materials. In other words, it is not sufficient to carry out analyses simply on the basis of a specific project plan (e.g. power station, supply line); upstream and downstream aspects and also, where applicable, the pretreatment of materials, must also be taken into account.
A prerequisite for analysis and evaluation of environmental impacts is a reliable database, which also describes the current environmental situation (initial loading) of the country or region in question. In this way it is possible to determine the extent of existing environmental loading and changes due to measures already executed or planned can be measured or estimated. Such data (e.g. environmental registers describing the extent of immissions in a region) are often unavailable, and must be gathered in order to arrive at a reasonable concept assessment, or replaced with suitable indicators allowing appropriate judgements to be made. When designing an environmentally acceptable energy system, national regulating bodies in other countries and international organisations can provide important information, even though such information can rarely be applied directly to the case in question. For example, when defining limits for discharge of pollutants into surface waters, it is essential to take the use of watercourses into account as well. The problem is often that the design of an energy system will displace pressing environmental problems to other regions or environmental sectors (substitution of firewood with kerosene, flue gas purification in power stations and disposal or use of filter dust and gypsum).
An important part of framework planning is the assessment of possible alternative forms of development and expansion. Such an assessment, which should also cover development caused by the energy supply and its possible environmental impacts, must proceed from the same objectives, i.e. it must refer to the same energy services to be provided. Attempts to evaluate alternatives based on a single assessment criterion (e.g. an "index of harm" or efficiency) have proved to be of little use. It is more a question of presenting specific environmental impacts in a disaggregated form to the decision-makers, identifying certain individual options in political agreement processes as viable and others as unacceptable. Various methods and computer-assisted procedures are now available to help with this task.
Nevertheless, individual options can be formulated under general objectives and assessed in terms of their climatic relevance, for example (individual quantities of pollutants emitted are aggregated in terms of their impact on the climate). This may also include "least-cost planning" studies (here an attempt is made to incorporate "environmental costs" and the costs of protective installations into planning calculations, and also e.g. costs of energy-saving measures). Particular reference is made to those projects in which economic objectives are placed alongside environmental objectives and accorded at least equal status. Creating this type of framework may also serve to identify, out of the large number of possible aspects involving adverse environmental impacts, those which are especially relevant to the assessment of the energy system. Such criteria range from the more technical parameters (e.g. degree of efficiency), to pollution variables (e.g. air pollutants, soil damage) through to risks, health considerations and rules on conditions in the workplace. Thus those projects or development variants which fail to satisfy certain minimum requirements (e.g. no use of hydroelectric power or no mining of deposits in conservation areas is permitted) can be ruled out from the outset; alternatively a preselection can be made on the basis of assessment of the contribution made by the energy supply system to an environmental problem.
Absolute priority in energy planning must be given to the search for options which, in all important aspects, involve the least environmental impairment. Coupled systems (use of an energy medium for simultaneous power and heat generation) and above all the use of renewable fuels are ideal in this respect. Even if a search for such options is unsuccessful, it is necessary to weigh up the individual aspects identified as important.
Changes to the energy system which subsequently help prevent or reduce adverse environmental impacts can basically be made in four areas:
(a) Energy saving
This range of measures takes existing structures and looks for possible ways of energy saving, with the side-effect of relieving pressure on the environment. Both technical resources and environmentally aware behaviour have a decisive role to play in this area. Many processes of energy use can be designed in such a way that substantial energy savings can be achieved (targeted replacement of inefficient components in old plants; greater use of coupled systems, i.e. simultaneous use of heat in electricity generation; use of combined processes in power stations to improve efficiency; instant measures such as use of fuel-efficient cooking stoves). But incentives for this are only provided if the price structure at least covers costs, and wherever possible includes supplements to cover environmental costs.
(b) Fuel substitution
In addition, there may be potential for changes involving individual fuels, e.g. biogas in place of wood, low-sulphur coal instead of sulphur-rich coal. More fundamental changes may also be possible (e.g. building for a particular climate thus dispensing with the need for air-conditioning). Greater use of local ("endogenous") potential in decentralised facilities may be a sensible alternative to central solutions (i.e. network- and line-dependent designs), with renewable en-ergy sources (for power and heat applications) being of particular interest. Moreover, decentralised solutions may to a large extent overcome the risks and environmental problems associated with energy transportation.
(c) Technical measures/investment
Pressure on the environment can also be directly relieved through measures to increase efficiency or reduce emissions from existing installations (e.g. flue gas purification, use of catalysts), to ensure optimum system management (e.g. adherence to optimum combustion temperatures) or to propose replacement of installations, with environmental aspects being taken into consideration from the outset. These measures are normally only feasible through additional investment and to some extent overlap with the measures referred to in (a). Pretreatment of fuels (desulphurisation) and special measures for safe storage or reuse following prior examination of residual materials (ash, filter dust) should also be considered at this point.
(d) Behavioural changes
Finally, energy demand notified can be analysed and behavioural changes suggested (changed mobility requirements, use of communal installations e.g. for refrigeration). Energy planning may reveal scope for behavioural changes and suggest recommendations. The question of achievability must be posed, and indeed answered, at political level; with the creation of general economic conditions which foster environmentally acceptable behaviour among the parties concerned becoming an important tool of OEP. OEP can only prepare for decisions at political level and support these through analyses.
Activities in all four areas rely to a large extent on support through education and the provision of information for the population groups affected (private individuals, trade and industry specialists, decision-makers). The facilities offered by the various media (radio, publications, lectures) must be used intensively and suitable educational provision must be made through the schools and colleges.
Considerable support for this can come from (public and private) institutions and organisations which, with their cross-sectoral expertise, can make effective contributions to finding solutions to environmental problems in the energy sector. "Non-governmental organisations" are increasingly important and such organisations should be supported in their work. However success also depends, in the public sector, on ensuring early coordination of the different development areas.
Influence on general economic conditions also plays an important role, since it is often only at this level that changes can be set in motion in all four of the areas quoted. Besides an active subsidy policy (e.g. for start-up financing), the expedient of fiscal policy (higher taxation of undesirable variants, if necessary to cover all anticipated "external costs") is particularly worthy of mention. But care should also be taken to ensure (particularly in the case of large-scale projects) that the costs do not outstrip the results achieved (taking particular account of the costs to the economy as a whole).
To summarise, once demand has been defined (e.g. the demand arising from the requirements of an industrial development project), whilst not regarding demand as a fixed quantity, one may proceed on the basis of the following questions:
- Is the demand understandable/justifiable or is it merely the result of explorations of a trend?
- Have all possible means of rational energy use been exhausted and the potential for savings been taken into account? Have alternative technologies and procedural proposals been included in the planning?
- Can different energy media be used to provide the services in question? Have all possible means of environmentally favourable energy media substitution been exploited?
- Are particular environmental problems in evidence regarding the use of the installations planned and have precautions been taken to reduce these through technical measures? Are disposal plans available for any residual materials? What are the main pollutants or overall environmental loads?
- Has account been taken of possible changes to general social and economic conditions which may affect future energy needs? Have the developments induced by energy production and their environmental consequences been noted?
- Have conditions been created whereby the measures at technical level will be supported by appropriate educational provision? Have promotional facilities been included and have the organisational requirements for supporting the measures been met?
Needs in other sectors (households, small consumers, agriculture, transport) can be dealt with in a similar way. Alternatives which are preferable in environmental terms are often more expensive (from the point of view of the individual business) than conventional solutions. In this case planners must consider whether implementation can be supported by appropriate price policy measures (subsidies, making unwanted variants more expensive etc.).
4. Interaction with other sectors
4.1 General objectives and socio-economic/socio-cultural dimensions
The aim of many countries is to improve their current situation, which may be characterised by population growth, malnutrition, lack of medical provision and hygiene, unemployment and regional discrepancies, and by largely uncontrolled consumption of finite resources. The energy sector is closely linked to these problem areas because adequate and financially viable satisfaction of the demand for energy services (e.g. in connection with drinking water supply and irrigation, medicine, production) may help alleviate these problems.
Overall Energy Planning (OEP) must take account of these guiding principles when the energy system is being developed. The desired positive effects will be achieved mainly in the final phase of development of the energy system, namely during the stage of actual energy use. Supply, i.e. extraction, conversion and distribution of energy must be designed so that positive aspects (of use) are not cancelled out. Conflicting objectives occur mainly where large-scale systems of energy extraction and conversion do not meet the objectives of the population of the region, involve unmanageable or unacceptable socio-economic and socio-cultural changes and consequences and assign costs and benefits to different social groups.
- OEP must take account of socio-economic and socio-cultural dimensions. This generally requires comprehensive analysis of the current situation and involvement of those affected in the decision-making process.
- In many countries, commercial energy sources do not reach the lowest social groups because of cost. Very often investments to build up infrastructure are not reflected in energy sources prices adequate to cover costs: These subsidies, which are granted on social grounds, do not reach poor population groups, especially those in the countryside, to a sufficient degree, thereby strengthening social inequality. A differentiated study of the preferences and purchasing power of each target group, carried out as part of an energy needs analysis, should provide valuable information for the design of appropriate supply chains and a rational tariff policy. Experience shows that the promotion of a decentralised approach to energy supply is an important tool for rural target groups.
- In the domestic sector, the introduction of new fuels often encounters resistance from the population, as traditional behaviour patterns will be disrupted. For example, attempts to introduce energy-saving coal or wood stoves often fail because insufficient allowance is made for other aspects of the stoves, such as radiation of light and heat, ease of use, safety, hygiene and aesthetics. On the other hand financial factors are often the reason why certain options cannot be taken up.
When it comes to supplying households with energy women are the decision-makers in many countries because they are responsible for production, collection and use of biomass resources (mainly firewood). Because of their particular position in the domestic energy sector, women have specialist knowledge concerning the use and management of biomass resources. This knowledge must be taken into consideration in the OEP context.
4.2 Interaction with other sectors
OEP must take into account the needs of all demand sectors in its regional and national diversity. However, it should also actively attempt to influence consumption patterns in order to achieve more environmentally acceptable energy systems.
This requires close harmonisation and coordination with a higher-ranking regional planning system to avoid misguided planning and to provide efficient and environmentally acceptable energy services. For example, there will be interaction with other planning areas:
(1) Regional planning: Development objectives of regional planning can be realised by OEP, since the availability of energy is a prerequisite for development processes. The connection of rural regions to the national power grid may also have an effect on urbanisation processes and counteract the flight from the land.
(2) Transport and traffic planning: An effective public transport system in towns and cities may reduce consumption of fuels and the resulting emissions if it has the effect of reducing the use of private cars. The linking of rural regions to a traffic system will increase the attractiveness of those regions, and in many cases is essential for commercial activity (linking to distant markets).
(3) Industrial planning: The development of industry requires an adequate supply of energy, particularly electricity. The decision as to whether one should develop energy-intensive (and at the same time usually environmentally polluting) sectors (basic materials such as steel, aluminium, chemicals) will affect the extent of likely effects on the environment.
(4) Agriculture and forestry: Reference is made to the problem of use of biomass as fuel, and related effects on agricultural land-use. Increased afforestation is required in many regions for fuel and may lead to competition with agricultural use of the soil. The agro-forestry industry may offer possible solutions in this regard.
(5) Water resources management: Environmental impacts mean that OEP must be geared to the needs of general water resources management planning. This applies, for example, to the competing use of water for power generation, irrigation and water supply, and for the introduction of cooling water, or the mutual exclusivity of power station sites and domestic water catchment areas.
In addition, there is a major interface with various political areas, whereby perceived needs can be incorporated in concrete general and detailed planning. Besides the field of energy policy which is discussed below, these of course include other areas such as the industrial policy or environmental policy adopted.
(6) Energy policy: Promoting the objectives of environmentally acceptable energy planning calls for an energy policy which takes account of the actual social costs of provision and utilisation of the energy sources. These objectives can be achieved to some extent through legislation (e.g. emission control regulations, safety requirements, import guidelines), but the attainment of other objectives relies on individual decisions by users. In this case, influence can only be brought to bear through pricing. For example, in many countries the - environmentally desirable - process of substituting the use of firewood by liquid gas or kerosene suffered a severe setback when crude oil prices increased. Attempts to introduce environmentally friendly technologies (e.g. photovoltaic systems with energy-saving lamps, super-efficient wood stoves and ovens) often fail in rural areas due to lack of financial resources. Environment-oriented policy must take account of these circumstances through the introduction of suitable financing arrangements, subsidies or fiscal policies.
Basically it is necessary to decide whether possible ways of bringing targeted influence to bear on development processes is to be exploited through planning, which will then however depend on the availability of adequate financial resources to support desirable energy options, or whether "market forces" should basically shape this development.
5. Summary assessment of environmental relevance
Environmental impacts of the energy system will increase with growing energy consumption, and in densely populated areas have already reached levels (of air pollution for example) which pose an acute health hazard. OEP must take this situation into account with a view to alleviating environmental problems and reducing environmental loading to a tolerable level and, even at this early stage, laying the foundations for longer-term changes to the energy system.
It must be assumed that in many countries no great importance is attached as yet to the problem of carbon dioxide emissions, in view of very low per capita energy consumption. But if current growth rates (1980 to 1987) for fossil fuel consumption continue, developing countries will be responsible for 50% of CO2 emissions within the next twenty years. (Even though the deterioration in the greenhouse effect so far has been almost entirely due to the economic development of the industrialised countries, they will still bear primary responsibility for the problem). Only a global effort will have any chance of defeating the problem.
The basic elements of a strategy to reduce adverse environmental effects from the energy sector must be as follows:
(1) Saving of energy through rational, demand-led, economic use of energy in all areas. Here, as in the areas mentioned below, education and consciousness-raising are just as important as improved technical methods. Targeted use of financial incentives (pricing, taxes) or shaping of the economic framework, e.g. through dismantling of subsidies, are fundamentally important.
(2) Use of substitutes to replace energy sources which have a particularly adverse impact on the environment. Greater use of local resources and particularly of renewable energies. Here too, costs and financing are important issues.
(3) Full use of all possible technical and administrative means of reducing emissions of all kinds and of achieving acceptable ways of disposing of waste materials and residues. Development of appropriate (for the relevant target group) financing plans for requisite investments.
(4) Determination of the scope offered by changes in individual behaviour patterns and in general social and political conditions for shaping the future energy supply system. The OEP process should be anchored in a suitable institution representing the environmental concerns of OEP at all levels of planning and decision-making.
OEP has a wide range of tools to help it perform these tasks, ranging from direct financial incentives and regulatory measures to the promotion of research and development and provision of information to the public.
Buchwald, K., Engelhardt, W. (Ed.), Handbuch für Planung, Gestaltung und Schutz der Umwelt, Bd 3: Die Bewertung und Planung der Umwelt, BLV Verlagsgesellschaft Munich 1980.
Buedenbender, U., Energierecht, Handbuchreihe Energie Bd. 15, Resch Verlag Munich 1982.
Bundesforschungsanstalt für Landeskunde und Raumplanung, Energie und Umwelt; [German Federal Research Institute for Regional Geography and Regional Planning]; Informationen zur Raumentwicklung Heft 7/8, Bonn 1984.
Davids, P., Lange, M., Die Großfeuerungsanlagen-Verordnung - Technischer Kommentar, Berlin 1984; Die TA-Luft - Technischer Kommentar, Berlin 1986.
ECO Northwest Ltd., Review of Methodologies for Assessing the Environmental Costs and Benefits of Acquisition, prepared for Bonneville Power Administration, Portland 1981.
Foell, W.K., Management of Energy-Environment Systems: Methods and Case Studies, Wiley New York 1979.
Garnreiter, F., et al., Auswirkungen verstärkter Maßnahmen zum rationellen Energieeinsatz auf Umwelt, Beschäftigung und Einkommen. UBA-Berichte 12/83, Berlin 1983.
German Bundestag (Ed.), Protecting the Earth's Atmosphere - An International Challenge, Bonn 1989.
GTZ, Umweltwirkungen von Infrastrukturprojekten in Entwicklungsländern, Consultant - Tag 1985, Eschborn 1986.
Hall, P., Great Planning Disasters, Weidenfeld & Nicolson London 1980.
Hills, P., Ramani, K. V. (Ed.), Energy Systems and the Environment - Approaches to Impact Assessment in Asian Developing Countries, Kuala Lumpur 1990.
Hohmeyer, O., The Social Costs of Energy Consumption, Springer Verlag Berlin 1988.
Holdren, J. P., Energy Hazards; What to Measure, What to Compare; Technology Review, April 1982.
Hübler, K.-H., Otto-Zimmermann, K. (Ed.), Bewertung der Umweltverträglichkeit, Blottner Verlag Taunusstein 1989.
Jarass, L., Auswirkungen einer Dezentralisierung der Stromversorgung auf das Verbund- und Verteilungsnetz, in: Bodenbelastung durch Flächeninanspruchnahmen von Infrastrukturmaßnahmen, Bundesforschungsanstalt für Landeskunde und Raumordnung (German Federal Research Institute for Regional Geography and Regional Planning (Ed.)), Bonn, 1989.
OECD, Emission Standards for Major Air Pollutants from Energy Facilities in OECD Member Countries, Paris 1984.
OECD, Environmentally Favourable Energy Options and their Implementation, Environmental Monographs No. 2, Paris 1986.
Rat von Sachverständigen für Umweltfragen, Energie und Umwelt, Sondergutachten, Verlag Kohlhammer Stuttgart 1981.
Rat von Sachverständigen für Umweltfragen, Materialien zu Energie und Umwelt, Verlag Kohlhammer Stuttgart 1982.
Seattle City Light Corp., Strategic Corporate Plan 1987-88, Seattle 1987.
Strom, P.-Ch., Bunge, Th. (Ed.), Handbuch der Umweltverträglichkeitsprüfung (HdUVP), Erich Schmidt Verlag Berlin 1988 ff.
UNEP, The Environmental Impacts of Production and Use of Energy, Vols I-III, Nairobi 1979; Vols IV, V, Nairobi 1985.
Umweltbundesamt (German Federal Environmental Agency): Medizinische, biologische und ökologische Grundlagen zur Bewertung schädlicher Luftverunreinigungen; Sachverständigenanhörung, Berlin 1978.
UNEP, The Environmental impacts of production and use of Energy.
Vogl, J., et al., Handbuch des Umweltschutzes, Verlag Moderne Industrie, Munich 1984.
Williams Silveira, M. P., Energy and the environment: technology assessment and policy options, UNEP Industry and Environment, March 1990.
