Although many other avenues certainly exist to provide energy services with less associated pollution to all, a ... people are, that resources are needed and definitely where they will be used. .... There are certainly other ways ofjudging of the friendliness of some renewable .... As an exemple, the dispersion of a city may.
Solar Energy in the Urban Planning Process: New Opportunities and New Tools Eduardo de Oliveira Femande&, Francisco I de Almeida2 ‘Professor, Faculdade de Engenharia da Universidade do Porto, Porto 2Architect, Parque das Naçoes, Lisboa
ABSTRACT The environment as a fundamental issue regarding the future is gradually becoming less a problem of fighting the dysfunctions affecting the environment caused by wrong decisions or mismanagement of the natural resources. The time is ripe to adopt a prospective view of the impact of all factors of pressure on the environment prior to committing to any major action regarding the use of the territory. Energy is certainly the most relevant factor of pressure on the environment with the particularity that the conversion and use of most of its forms, mainly fuels, may produce pollution that by its quantity and nature will have a strong impact at all environmental scales: indoors, local, regional and global. For about two centuries energy was mostly identified with fossil fuels and seen as a commercial good or a production factor. Quite recently it became clear that energy must not be used without closer reference to environment values. This leads to a much wider approach to the energy issue in which solar energy must and surely will play an important part. Solar energy, one of the basic energy resources for thousands of years, was not ready to compete neither in quality nor in quantity with fossil fuels. A new era for technological solar energy emerged with the exploration of outer space and the oil crisis of the 70’s and 80’s. However economics kept solar energy applications from being promoted, as they should for the last 20 years. The best compromise between energy and environment implies the appropriate balance of both the energy supply and energy demand perspectives. Cities are called to play a crucial role both in the management of the best opportunities regarding the energy options for their citizens and in the articulation of energy options with environmental objectives. Solar energy can be managed from both sides at the city level.
INTRODUCTION The environment as a fundamental issue today and for the future is gradually becoming less a problem of running after the effects of past poor decisions and past mismanagement of natural resources. Much has to be done and has being currently under way to correct the effects of an industrialisation and an urbanisation based on an absolute belief on the power of technology propelled by a culture of rather cheap oil. The time has arrived to adopt a prospective view of the impact of all factors of pressure associated with human activity on the environment prior to any action regarding the use of the territory. However, it is hard to identify the parameters and the criteria for which target values can be set. This is particularly true for the urban context where the complexity of variables involved is
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enormous while the practice has mostly been guided by theoretical concepts of a cultural or sociological character. This type of concepts whatever their cultural basis would be do not offer any means for the monitoring of their performance whenever they have been put into practice. As an example, it has not been easy so far to city managers, among many other actors, to identify the subtle connection between the urban strategies and the levels of energy use in buildings as well as in transport systems and their consequences on the environment at all scales. Energy use is probably the most clear and direct link between the ‘local action’ and the ‘global impact’ through the growing CO2 concentration in the atmosphere due to the current energy paradigm: combustion. That is the reason why some models are already identifying the annual CO2 emission per capita as a kind of universal indicator for the friendliness of a particular city in what regards the global environment. A figure of 3,3 tons per capita per year has been advanced as a value corresponding to the stabilisation of the CO2 concentration (CO2 equivalent meaning to integrate the contribution of other greenhouse gases) in the atmosphere by the year 2050 [1]. Many cities nowadays have a production of over 30 tons of CO2 per capita per year. This global criteria has quite recently achieved scientific consensus and is now the subject of world-wide political concern, with important recent milestones namely at the Rio Conference (1992) and Kyoto (1997). The importance of the issue is not diminished by the unfortunate political difficulties that have repeatedly frustrated the reaching of an agreement in the successive meetings after Kyoto. Although many other avenues certainly exist to provide energy services with less associated pollution to all, a global political agreement is becoming increasingly necessary and urgent. What appears to be clear is that a great effort must be put into more efficiency to obtain the same or equivalent benefits or effects with the employment of fewer resources whatever technologies and processes are going to be used. The combustion paradigm must be substituted in the future but that will take still some time. In between, there is a need for more efficient energy systems both at the supply and at the demand side. That is why this approach implies that a special attention must be paid to what is done and how it is done at the user level in order to influence also the behaviour of the suppliers of the resources. In such a context it is worthwhile to evaluate what can be the role of cities and of the urban environment in this process. The urbanisation of the world population is increasing very quickly with the fast growing number of megacities. Figures around 60% may correspond to the actual share of the World population living in urban environments. It is in the urban areas, where the people are, that resources are needed and definitely where they will be used. So, cities represent a considerable environmental challenge because of the complexity of the urban systems but also because they are a good opportunity, maybe a unique one, to implement concepts crucial to sustainability [2]. That is particularly true, as cities seem to be particularly favourable to the compromise between the supply and the demand side. The city approach implies abandoning the traditional dominance of the supply side perspective that used to strive for increasing profits by stimulating needs and thus enlarging the market. Instead, that must be balanced and priority must be given to a demand side approach aiming to reduce actual needs through the efficient use of energy, without making any concession in what regards access to the best living conditions that each specific socio-economic situation will allow. That is the challenge regarding the implementation, among others, of the most energy efficient transport systems and the most energy efficient buildings.
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SUSTAINABLE DEVELOPMENT Energy use, definitely the link par excellence between human activities at the local level and the dimension of their global impact, cannot be isolated from the context of its applications. The context could be summarised in a statement taken from the Agenda 21 [3]: “There is a new global effort (imperative, one would say) to relate the elements of the international economic system and mankind’s need for a safe and stable natural environment”. This context could be defined by the relationship between the actual World situation and sustainability, certainly a major human target, as pointed out by the Brundtland Commission (1987): “a model of development that allows the present generations to meet their needs without jeopardising the same possibilities to the future generations”. One of the difficulties today is, certainly, very much centred on how to materialise the concept of sustainability in order to make it operational. The definition of sustainability, however, encompasses the whole human life and develops through three major “fingers” of the human handprint upon the environment: economic, social (and health) and ecological. An attempt to define its scope could identify perhaps five main actions: international (global) co-operation; combating poverty; managing the demographic dynamics; protecting human health; and promoting sustainable human settlements. This, by integrating environment and development at the policy, planning and management levels through dignifying human living conditions for all under broad criteria of conservation and proper management of resources. The added pressures on the environment generated by the need to solve all the existing discrepancies in levels of development and quality of life cannot be disregarded. While there are 2,5 billion people still without any access to electricity, there are also countries with energy consumption per capita as much as four to five times the World average. And this consumption is not justified by its true need at the user’s level but is the result of uncontrolled inefficiencies totally unacceptable and, even, unethical in the actual stage of knowledge and technological development. So, naturally, there is an imperative to do all the necessary to supply energy services through the most efficient and environmentally friendly means but this shall not hide or deviate from the most urgent needs of billions of people around the World. The strategies under discussion for the ‘C02 market’ contemplate, at least in principle, all those different aspects of the problem. The CO2 market is an issue at the international level. In this text the intention is not to cover the whole with of the “sustainability” scope. The aim is to focus on the implications of the concept upon the exploration of energy resources and on the fulfilment of the people’s energy needs, bearing in mind all impacts on the environment at all scales and stages of energy manipulation. More specifically, the focus will be put on sustainable cities or sustainable urban environment, i.e., on what seems to be relevant and on what can be done at the urban level to meet the socio economical targets without irreversibly damaging the ecological values. It starts from the point of view that urban planning processes and activities, either for fully new urban spaces or for urban rehabilitation, need to have the impacts of human intervention at the urban scale assessed in terms of the environment at all scales: indoors; local, regional and global. The local and regional scales were the most considered in the last fifty years. Indoor environment, where people spend probably more than 90% of their life cannot be forgotten any more. The global scale appears to emerge as the unifying global parameter and representing some kind of recall for global fairness.
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Nevertheless, a systematic treatment of the issue of sustainability is still lacking. The methodologies and the criteria for intervention are far ftom established. It is well known that there are today hundreds of cases of experiences in urban developments conducted around the World that claim to be sustainable. Far from denying grounds for their claim, what is puzzling and can even damage the propagation and generalisation of the concept is the biased character of many of those experiences. Some emphasise actions regarding water management; others emphasise traffic enhancement strategies and still others just the greening of the urban landscape. Approaches centred on some particular aspect cannot avoid the criticism of potentially bringing some prejudice to the sustainability of the whole. In addition, by pretending, even in good faith, that a correct and general enough procedure has been adopted, as it has often happened in the past, one may even discredit the whole concept of sustainability, creating kind of immune reaction to the adoption of better and more holistic methods. MANAGING ENERGY AND ENVWOMENT The problem is that common criteria for intervention in the territory do not exist and there is no accepted threshold or level of human intervention that warrants the right to consider a particular intervention sustainable. As a first attempt, it seems that the general approach could be based on the well-known OECD model PSR (pressure state of the environment response) whichever of its variants could be used (Fig. 1). The model is simple and establishes clearly the difference between the state of the environment and the factors of pressure on the environment. The traditional way of managing the environment, mostly because of the defensive approach taken to environment issues by the generality of the economical activities, is either conservationist or of an healing character. With the exception of the cases where the environmental impact assessments are specifically required, the focus of the environment management policies is generally put on the status of the environment. —
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However, every human intervention is generally cause for environmental dysfunction, i.e., it is a source of pressure on the state of the environment. That must be anticipated and its potential negative impact must be weighted against the positive results to be expected. In this search for a sustainable balance the determinant role will certainly come to the decision-making most often at a dramatic moment where the economic impact of the project seems more pressing than the foreseen
Factors of pressure over the environment
State of the environment
Strategies, Actions, Actors
Fig. 1
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The OECD PSR model -
damage to the environment. It may be the role of the environment actor or of the managing entity engaged or attentive to the planning process to provide the right inputs and the proper way to help
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shape decisions favourable to environment. This shall occur enough in advance to avoid the dramatisation that is commonly present at the occasion of the environmental impact studies. Mi the issues, methodologies and tools linked to environmental impact assessment must be summoned up here. It is well known that solutions are not yet available for aspects like the estimation of the cost of externalities. Several studies have been conducted throughout the World, in particular to establish the externalities of electricity production. However, a properly balanced framework for the evaluation of the multifarious environmental impacts still does not exist. The plans to establish a CO2 world market is certainly a major step, at least for what regards the global level. It is important to state that energy is part of the environment and that it is the energy manipulation, from its extraction through its conversion, transport and use that may have negative consequences upon the environment. In fact, energy became a commodity and people, even those invested in positions of responsibility, are not yet necessarily sensitive to the fact that energy is much more than a commercial good but is actually a natural resource. The concern for the scarcity of potable water, for instance, appeared much sooner and propagated much more easily. That is why measures to better manage water resources by namely giving several uses to the same flow after its first use in a kind of a cascade approach, can be seen reported everywhere. In spite of the energy crisis of the late 70’s and early 80’s, that does not yet apply for energy. In fact, all primary forms of energy, whether fossil or renewable, are part of the Planet, and the question of their scarcity is compounded with that of the interference of their use with the environment. The combustion of fossil fuels produces gases and particles, whereas renewable, particularly for large power plants, also cause non-negligible impacts such as those associated with hydro-power units, wind farms and biomass use. The environment, namely through the CO2 effects, is showing how careful Man has to be with Nature, at all levels and scales. That is why energy use must be re-organised to assure articulation of its drawbacks in terms of environmental values. The “energy service” concept is a basic key to reconcile environment and energy (Fig. 2). The notion of energy service puts into question efficiency rather than consumption. Efficiency extends to the choice of the most adequate form of energy for a specific purpose and location. It is efficiency that has to be enhanced and not consumption that has to be reduced.
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Fig. 2
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The concept of energy service
The enhancement of efficiency does not mean the reduction of people’s access to comfort levels and amenities. It is possible to reduce energy used in buildings by more than 50% in a foreseeable future. Experiences like the urban development of EXPO’98, Lisbon, Portugal [4J are good
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illustrations of that potential. But many other experiences around the World can be documented. To reach and even to go beyond those figures it is necessary to excel with technology and not only that. There is a need for a cultural change as there is a need for political vision and wisdom, Efficiency is not necessarily associated with a single device, equipment or process but it must also bear in mind the whole system or systems. The impact of the enhancement of energy efficiency referred to above can become clearer and even more obvious if it is realised that, as taught by Thermodynamics, the complement for the efficiency of an energy process associated with combustion is always an environmental dysfunction. What is not converted into useful energy e.g. as the driving force in a car or as electricity in a conventional thermal power plant is necessarily dumped into the environment. The energy wasted is negative not only per Se, in the sense that there is production of something useless. It is negative also because of the fact that that waste will be somewhere a cause for some harm to life, to the ecosystems and to the necessary equilibrium to the environment, The implications of the energy service concept can also be directly reflected on the assessment of the friendliness of the renewable energies. In fact, for instance, the non efficient use of the wind energy does not represent necessarily a drawback to the environment since the wind will continue almost without any disturbance introduced by the wind mills. The same applies, of course, for solar energy in general. There are certainly other ways of judging of the friendliness of some renewable plants such as the impact on the local ecosystems or on the landscape. CITIES
AS PRINCIPAL ACTORS
In that sense every city must be seen as a system. Cities, from the point of view of the energy use, are very complex systems that need to be approached exactly as systems. Therefore, to plan for a sustainable city from the energy perspective requires the establishment of the adequate targets and of the proper methods for planning and designing it as well as the tools to assess the results against benchmarks that may need to be reset from times to times. If the utilities are changing ways of performing on the market, actors such as the natural gas and the heating and cooling networks are new competitors trying to gain their share on the market. All this represents a natural trend for the energy supply side in a every day more open market. Their final product under the form of ‘final energy’, be it electricity, natural gas, hot or cool fluids, will tend to be required to be made available freed from any environmental charge. In a city there is a need to pay particular attention to the demand side. Architects, in general, tend to focus on the urban object and its nearest environment such as the street or the square and to ignore in most of the cases the environmental relevance of their options outside the square or the plot. There is a lack of awareness about the impact of the options taken at the local level on the global environment through the choices regarding the energy to be used. A similar situation happens in the perspective of the urban planners. The latter are called to deal with a wide spectrum of qualitative parameters or data that is not enough worked out to be directly usable for the urban planning profession. Just to give an example, for many years the climate data was produced in formats that were of very little interest for building energy management, including for building design or for urban planning.
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The position of politicians tends to be also quite fragile in this regard. There is the tendency to confine the environment reporting to the quality of some elements (air, water, wastes, noise, etc.) and to forget the most complex issues such as the use of the territory and the role played by the urbanisation and the transport as global environment pressure factors. Of course, industry is also a pollutant activity. The novelty here is that industries are probably today the most controlled pressure factors as their condition, in particular for a growing number of countries, overwhelms the national borders because of the international rules for the market which are against the dumping of the compliance with the environmental rules. Transportation and buildings are the more difficult parameters to control as they are more dependent on the population behaviour. The above represents a great challenge for management as it asks for an integrated vision and for a very well lubricated “consensus building facility” both through a democratic approach and by the contribution of open minded competent actors. That is what urban sustainability is about. The illustration on the Fig.3 expresses what could be a model of how the dynamics of the participation of all actors in the city context could be organised [5]. Energy and Building Technologies
TOP-DOWN
SUPPLY SIDE
BOHOM UP -
Fig. 3
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Integration not only ‘within’ the architectural object: the problem of urban process
People involved must be knowledgeable, because this approach is not compatible with the business as usual type. The best available technologies and tools must be accessible. The city must then call upon all different interlocutors dealing with energy, as large consumers or representatives of community sectors (inhabitants, commuters, etc.) to capitalise on their adhesion to a wide spectrum of demand side management strategies facilitating the technological support and assuring the best information channels possible. fllDICATORS The need for some way of assessing urban planning procedures and results (a system of indicators or other tool) that can function as reference for all exercise related with the urban planning and the urban management has been felt. The situation finds some parallelism with what happened with buildings in the late seventies early eighties when the energy issue emerged through the angle of the scarcity of resources. Each building was considered a single case and lots of tests were done and documented to illustrate the ‘success’ of a particular solution but with little and slow impact of each experience on the building design process. And, yet, the reality tells us that for a given plot or location and a particular brief there are more than a billion possible architectural solutions. So, besides the spatial implications
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taken care by the architecture, whatever the architecture solution and the style adopted are, what seems that should matter mostly is the possibility of knowing the performance in terms of energy used or, in broader terms, their environmental impact. That means that, from the point of view of the enrichment of the existing culture with energy and environment information about the built environment or the generalisation of the concept of sustainable buildings, the solution may not be the replication of a successful case study as such. On the contrary, it is the capacity of transferring towards other cases the hidden lessons of the preceding experiences. Nevertheless it took quite sometime to researchers and to other professionals to have a global vision of the problem and to have access to a panoply of methods and tools of simulation of the thermal behaviour of buildings. And, finally, nowadays it is possible to have access to different computer models for the energy use in buildings and to define policies and fix targets based on those tools. The same has to become possible for the urban environment. There are many ways of approaching the urban planning and the urban management. It is clearly a multidisciplinary issue that, hopefully, can be seen and dealt with as an interdisciplinary issue, i.e., not following an ‘add on’ type of procedure but under an integrated approach. The weakness of the urban planning process is based on the fact that the integration of the information given by all data available independently of their quality or even their relevance is mostly the result of a subjective evaluation and a discretionary option. —
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So, to be able to do better urban planning and management it seems essential to be able to assess the results of the urban planning and management activity. But, this is not an easy task. It is not just a matter of quantification. This question has been approached by some very original ways, in particular by Japanese municipalities as well as in many countries in Europe and elsewhere. For that purpose it is necessary to get clear about the type of indicators and the method to use them and clarify what is the true meaning of criteria to be used and their own individual relevance.
OBJECTIVES AND CRITERIA FOR INDICATORS Antecedents
There are maybe something like hundred systems of indicators around the World of very diversified scope, with different characters and purposes. Some are promoted by international bodies (UN, OECD, WHO,...). Other systems of indicators have been launched by National Governments. And, finally, other systems were established by cities or private entities, in the latter case, either just for knowledge sake or services rendering purposes. The number of sustainable indicators proposed and used by those different institutions and many others in the international and in the national scene, is quite large and presented under quite diversified perspectives. Some indicators are of a statistical character and allow for keeping an observatory on how the social, the economic and many other aspects of people’ life in the World is evolving. In this sense those indicators, as all statistics, can have an obvious major contribution towards the planning initiatives.
Among those systems of indicators two could be referred to, just to illustrate how different can be their character even if all are put under the aim of the sustainability. The system of the United
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Nations Centre for Human Settlements with chapters such as background data, socio-economic development, infrastructure, transport, environment management, local government and housing. Is the case of a list of indicators very broad in scope aiming at documenting the state of the soclo economical development particularly in the developing World. Instead the system PLACE 3 S (USA) [6], closer to the urban environment, has chapters such as: landform, microclimate, land use, site design, transportation infrastructure efficiency and on-site energy resources. This system contains a model that allows estimating, for instance, the CO2 production starting from different planning options and being therefore used as a planning tool. This is a very specific set of indicators quite oriented towards performance indicators to be used in urban developments.
SINOPSE-A (Portugal)
Sinopse-a is an acronym that stands, in Portuguese, for ‘system of indicators for urban planning addressing the energy and environment’ related aspects. The objectives set for Sinopse-a are mainly to convert data into information; to make the latter more available as to favour the interaction among different actors in the urban planning and management process; and to make that information as explicit and as objective as possible. It shall allow for a wide spectrum of users and to allow decision-makers to interpret such information in a clear and objective way. More precisely, Sinopse-a is a set of indicators that may help bringing objective information to assess the evolution of the urban planning process at each step from the early phase of the design stage through the management process. The Sinopse-a system has the form of a matrix of indicators bearing in mind for a city, considered as a ‘control volume’, the three ‘sides’ of the OECD ‘triangular model’: pressure on the environment; state of the environment and response initiatives. The reference case is the assessment of energy as the urban pressure factor. The selection of energy as the pressure factor to be considered finds its background on the fact that CO2 may become the most relevant parameter to assess the environmentally friendliness of all urban options with energy implications at the city level. The reality tells us that most of the activities have an energy consumption implication. As an exemple, the dispersion of a city may imply higher energy use for transport or for other infrastructures. On the other hand the design of the city may interfere with the energy efficiency of the end users (buildings, industries, etc.). In more general terms, the enhancement of the existing infrastructures, the retrofitting programmes of the old building stock and the renovation of public buildings, etc. or the simple management of the energy uses in the city can be checked against a such a system of indicators. In addition, the energy issue must not be approached separating the supply side from the demand side. The development of new urban areas in response to identified needs for housing or business activities cannot be taken ignoring the contribution of the new built areas with their inherent energy consumption towards the CO2 emissions. On the other hand, their potential to explore other available options for energy supply such as solar must be evaluated. For a given territory the resources available must be assessed as well as the feasibility of their exploitation at different levels, be it under solar thermal panels for domestic hot water or too simply through a better urban
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and architectural design to respond to the climate conditions. This latter aspect means that the energy needs expressed in terms of the commercial energy used by different activities can be reduced at a first attempt through a ‘source control’ approach which will lead to lower needs of the energy that will have to be provided by the city networks. The indicators are classified into three cathegories: 1)- Informative, which depict the situation as it is at any time. They can vary from geographic limits to statistics on all relevant parameters, etc.; 2)- Prescriptive, which are those associated with the legislation, the standards and the rules which compliance is compulsory; and 3)- Performance, which tend to be the critical ones as they may give the support to establish the target values and to define the criteria to be proposed for a given intervention. They will pier the assessment of the quality of the results comparing the actual situation at any moment with the set of targets established beforehand. The performance indicators may be considered as informative for the situation in the past but will become targets against which the future situation must be assessed. There is a challenge associated with the definition and the calculation of those performance indicators. Some may be too evident and others less. The aim shall not be to start by being too exhaustive taking into consideration all possible indicators but, instead, shall consider those indicators that offer some degree of being immediatelly accepted and can be recognised as becoming effective as tools for the planning exercise today. The indicators are applied at six main levels: one, at the global dimension, and five at the local/regional level (Fig. 4): 1) Global The global environment is sensible to the actions taken at the local level through the energy use; 2) Resources When dealing with a given territory or a space, before thinking about other sources of energy to be imported from other areas, regions, countries or continents, it is necessary to evaluate what is the endogenous capacity of self providing energy resources; 3) Use of the soil The soil is a basic resource and its use is essential to the good efficiency of all resources under a sustainable perspective; Morphology Probably the most crucial environmental aspect since the soil occupation 4) strategy in the urban context can interfere with the energy use: the density of the built environment, the orientation and dimension of the public spaces, the areas of greenery, etc. The city evolution is mostly controlled by economics and cultural criteria and do not usually take into due account the environmental impact; -
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Fig. 4
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The SINOPSE-A proposed indicator levels
h?fra-structures As the supporting tools of the urban life (water, waste, electricity, transport services,...) all of them are using quite some energy. In fact the infra-structures may be thought and organised through many different ways to be less dependent on energy consumption; 6) End users At this level there is room for many wise actions towards more energy efficent use. 5)
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Within those six levels, a number of current themes with environmental relevance, from the basic elements (air, water, soils, green cover, etc.) to others of infta-stmctural character, may be considered. Each theme is considered every time it has relevance at a particular level. For the case of energy it is well known that it has impact at all levels: at the global level, by the greenhouse gases emissions associated with namely the combustion of fuels; at the regional level, as energy resources conversion and use, wether available or imported, may have regional environmental impacts; at the city level, with all the potential of the ambient energy (solar radiation, air temperature, water and ground thermal energy sources, etc.) to be explored under a demand side perspective but also the solar radiation to be used as electricity (PV cells) or as domestic hot water, from the supply perspective; and also the current panoply of other energy forms used at the city level has impact at the local level. The optimisation of the role of the energy services and of the efficiency of the energy infra-structures is essential in this issue. Finally, the behaviour of the industry, transport and buildings, is a key parameter on a strategy towards a sustainable city. F or those different levels it is possible to define indicators and to give values to them which can function as targets for the planning. Just as an example it is the recent indicator concerning the energy use for heating expressed in terms of kWWm2.year. But many others do exist and show their relevance for the enhancement of the energy efficiency of buildings and hopefully of entire urban developments. The same could be said for many other themes. The problem arises that for each theme at least one indicator should be identified which may lead to a large number of indicators making their treatment very difficult if not even impossible. Therefore, some reasonable way of selecting the themes and the criteria must be identified to reduce their number to a reasonably handy number.
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-Ldsc,e Ib4ate Ecdcgy Øce
arJ McrocIrite
Fig. 5
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The STNOPSE-A proposed matrix
To satisfy their role the indicators must fhlfil some criteria. They must be representative of the situation; simple and easy to interpret; soundly based and properly documented; as universal as possible in the sense that they must allow for comparison among different cases and contexts; quantifiable through target values or guideline against which its performance may be compared. To build a matrix is justified because the reality is too much complex, and the search for single figures which could take into consideration all effects in one may be too reducionist or distort too much the reality. A sensitive analysis may be needed in order to identify among the applicable indicators which ones are the more relevant ones. A matrix will allow for putting into evidence the most relevant parameters, which may form for each case a specific ‘skyline’ (Fig.5) which may differ from city to city depending on the geography and on the so many parameters that mark the idiosyncrasy of each city. In the FigS, the levels are represented on the left-hand axis while on the right hand axis are represented the themes. For each cross point one can represent one or more specific performance indicators there can be more than one performance indicator for a theme at a given level. The height of the bars indicates the degree of compliance with the targets. Therefore, only relevant themes at relevant levels will have a bar represented. The height of the bar illustrates the degree of thllfilment of the performance indicator associated. The ‘skyline’ shows not only the indicators that are relevant on each case but also the degree of accomplishmente reached for those indicators. —
On the Table 1 there is an illustration of how could the same matrix be represented under a different perspective. On the x-axis are represented the three types of indicators and on the y-axis the six diferent levels. At each cross point it is indicated, as an exemple, one possible indicator. This allows for a judgement on the potential of the system Sinopse-a. Picking up just one example: for the global level, the CO2 concentration is an information that can be obtained worldwilde while the emissions of CO2 is something under the responsibility of the city, i.e, it is dependent on the city energy or environmental performance. For the other levels the exclusive preocupation of illustration led to mention several themes liberating each box from being coherent with its neighbours either to the right or to the left.
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Two applications were already made for two small municipalities in Portugal, one near Lisbon, of a rural character and other, near Porto, of a suburban type. The results are very encouraging. The format will ask for information that is not usually neither requested nor compiled and end up by giving a new picture of the reality for the city. Of course the final aim is to be able to have models, to simulate the behaviour of city and to antecipate the performances. But, already at this stage the number of performance indicators that can be identified and quantified on the field is much higher than it could be expected at the biggining. Table 1
Level Global Regionalllocal Resources Land use Morphology Infrastructure End-users
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Relationships between selected S1NOPSE-A indicators (example of application)
Nature Informative CO2 concentration
Prescriptive Kyoto Agreements
Performance CO2 emissions
Endogenous water Present land uses
Rivet basin plan Zoning plans
Water extraction indices Conformity index
Surface permeability Waste production Car ownership
Solar access law Waste recycling laws Public transports
Shading indices Waste recycling indices Mobility index
On the Table 2, again just for the sake of illustrating, there are some data obtained from different references. Those are some values that can represent a departing point for the quantification of some indicators. As examples, the case of the CO2 can be mentionned. As well as the case of the urban waste production [3]. For the latter case ther are figures available (informative indicator) but it is known that some reduction could be reached. This should open up for the setting of some targets [4]. This Sinopse-a is part of a proposal prepared for the Portuguese Ministry of Planning [7]. The aims are to implement the concepts explained above bearing in mind the local context but with some ambition of making a more systematic approach to the whole issue. As a consequence some experimental application of the concepts defined was already possible to try to collect information on the acceptance of the method. The fact that no reference is made to the socio-economic parameters is because they are not considered as indicators but, instead, as the framework on which everything happens and is justified. Table 2
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A few selected SINOPSE-A indicators and related potential targets INDICATOR
CO2 per capita (1 kg/year) CO2/m2year (kg) Energy intensity of GDP (TEP/MEuro) Heating energy (C. Europe) (W1h/m2ano) Rrenewable in the energy mix (%) Water (litters per person day) Urban waste (kg/resident year) Urban waste valorization (%) Building materials recycling (%) -
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Guidelines Objective Conventional 3,3 10-40 50 10-200
