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The current policies aimed at promoting the decarbonization of existing buildings under the principles of the circular economy are in need of practical measures tailored to local conditions to increase their effectiveness. The lack of standard practices for assessing buildings’ refurbishment strategies toward energy efficiency and CE principles reflects this reality. To tackle this issue, a new framework for refurbishing circular buildings, is proposed in this paper, based on circular procurement and incorporating a lifecycle perspective. This framework articulates a dialogue between local authorities and private stakeholders through a set of steps that encompass building mapping, selective disassembly, (re)design, and (re)build practices, providing opportunities to implement policy-based incentives. The application of the framework within the Portuguese context demonstrates the potential to identify critical moments within the refurbishment process that can materialize in a new set of CE policy actions to be implemented at the building level. These policies are aligned with local construction permitting procedures and take advantage of the resources and incentives offered by the local administration, such as tax incentives.

During the last two decades, Portugal has made efforts to implement a circular economy and its business models in industries, which has led to a series of operational and strategic initiatives. Nevertheless, after 20 years, further efforts are required for a larger-scale implementation of such models. This study aims to identify the current status in the legislative context of the industrial circular economy and industrial symbiosis (ICE&IS) in Portugal, with a special focus on the policies and incentives for the promotion of this model. The main objective of this research is to verify whether there are conditions for the promotion of ICE&IS, and the main aspects to reinforce the current Portuguese strategy. To achieve this objective, a mixed research approach was defined and performed. This approach is based on methods of gathering information and analyzing the results through a comparative policy analysis. The result of this study shows that Portugal still has a considerable number of gaps and needs (strategic, fiscal, and financial) that must be addressed for effective implementation. Our research suggests that Portugal will face a series of critical aspects for industrial CE implementation, namely, promoting effective incentives (i), simplifying the national strategy (ii), and dealing with bureaucracy (iii).

Cities are complex systems with a key role in economic development and in improving the environmental sustainability of nations. Therefore, a comprehensive understanding of urban systems is fundamental to designing relevant policies and initiatives. Urban metabolism characterization may provide a holistic framework for analyzing urban systems in the context of the broader national metabolism. This paper provides a methodology to characterize the metabolism of an urban area, such as the Lisbon metropolitan area, taking as a source of data the socioeconomic metabolism of the country. The national metabolism is established by computing physical input-output tables. The downscaling to the urban level is accomplished with a variety of sector-specific parameters, from which an urban mass balance is established for a set of economic activities. The results obtained for the case study of Portugal and the city of Lisbon suggest that the share of services and the type of manufacturing industries in the economic structure of Lisbon, together with the higher resource productivity in the most representative economic sectors, are key aspects of the metabolism that contribute to Lisbon having higher overall resource productivity. The representation of the metabolism flows revealed key differences between the supply chains of Lisbon and the national flows, as well as a strong dependence of the Lisbon economy on material flows from other regions.

This review paper organizes and summarizes the literature regarding climate change impacts on future building energy demand. The approaches used for the creation of future weather climate and building renovation scenarios, as well as building energy modeling at different scales, are evaluated. In general, it can be concluded that future heating demand could decrease (7–52%), while cooling demand could increase significantly (up to 1050%). The decrease/increase rates varied significantly depending on the climate and case study building(s) considered, with buildings and building energy systems located in extreme climates being more sensitive to such changes. The main uncertainty of the predicted increase/decrease rates can be assigned to climate models and forecasted weather data. Nonetheless, such forecast and risk assessment are necessary for sustainable development of urban environment and associated energy systems. Further development of dynamic large-scale building energy simulation tools is re...

Urban horticulture has historically contributed to the supply of fresh produce to urban dwellers and has been gaining popularity over the last years in the Global North, with growing awareness of environmental and health concerns. Over the past few years, commercial farms have been emerging in major northern cities, promoting a trend of environmentally friendly food, grown in highly efficient installations on top of or in buildings. This paper presents a scoping study, including: (i) a review of the scientific literature addressing environmental, economic and social aspects of commercial farming in urban contexts; and (ii) a consultation exercise to inform and validate findings from the review, consisting of semi-structured interviews with a few practitioners in the Netherlands. The main findings are: (1) while the recent proliferation of commercial farms in major cities shows that these new modes of urban agricultural production are gaining momentum, establishing their viability as compared to conventional agricultural practices is a challenge when it comes to scalability, resource efficiency, and cost-effectiveness; (2) as it is still a relatively new field, very few studies have been conducted to quantitatively assess the impacts of commercial farming in urban areas; (3) given the complex environmental, economic and social dimensions of urban agriculture, holistic decision support tools could help integrating them in urban areas.

Due to changing weather conditions caused by the global warming and building renovation measures triggered by new building energy efficiency policies, building heat demand in the future is likely to decrease. This effect could consequently impact the techno-economic parameters, feasibility and environmental performance of district heating (DH) systems. The main goal of this study is to evaluate the impact of global warming and building renovation on operational (heat generation) and economic parameters of district heating systems. As a case study, a prototypical district was created based on the district of St. Felix, which is located in Nantes (France). Weather and building renovation scenarios were developed for the 2010–2050 period, with a ten-year time step. Heat demand for all scenarios was calculated with a model based on thermo-electrical analogy, previously developed and validated by the authors, while the network techno-economic parameters were calculated using a tool developed by Veolia Research and Innovation for the internal corporate use. The results indicated that the decrease of heat demand proved to be the highest after the first year of renovation (2020), decreasing by 52% of the reference value (2010). Accordingly, DH linear heat density decreases bellow the profitability minimum for traditional district heating networks. The participation of natural gas peak boiler in heat production increases over the studied period, while the participation of base load biomass boiler decreases, due to the fact that the number of hours with heat demand bellow the technical limit of the base load boiler was increasing. Consequently, CO2 emission levels increased. Heat production costs increased, with higher increase rate for the scenario where the new district heating network is planned, compared to the scenario with an existing network.

The feed-in tariff (FIT) program is a popular policy for incentivizing new renewable energy projects because it establishes a long-term contract with renewable energy investors. This paper presents a novel model to analyze a FIT contract with a minimum price guarantee (i.e., a price-floor regime) from an investor's perspective. The results show that a perpetual guarantee only induces investment for prices below the price floor when offering a risk-free investment opportunity. In contrast, the finite guarantee may induce investment even when the revenue from the guarantee is lower than the investment cost. When an investor faces a scenario with regulatory uncertainty, a higher and more likely reduction in the price floor induces earlier investment. For all cases, investors postpone an investment decision when market conditions present a higher price volatility. (C) 2018 Elsevier B.V. All rights reserved., The authors gratefully acknowledge the anonymous reviewers for the many useful suggestions that greatly improved this article. This work was supported by a PhD scholarship provided by Fundacao para a Ciencia e a Tecnologia (FCT) through the MIT Portugal program under project SFRH/BD/52086/2013, and was supported by national funds through Fundacao para a Ciencia e a Tecnologia (FCT) with reference UID/CEC/50021/2013. In addition, this work was carried out within the funding with COMPETE reference no POCI-01-0145-FEDER-006683 (UID/ECO/03182/2013), with the FCT/MEC's (Fundacao para a Cincia e a Tecnologia, I.P.) financial support through national funding and by the ERDF through the Operational Programme on "Competitiveness and Internationalization - COMPETE 2020" under the PT2020 Partnership Agreement.

Urban energy modelling requires a large amount of detailed data to perform systematic dynamic simulations of a large number of buildings, where the adoption of energy efficiency strategies is an important concern for sustainable urban planning. National statistical datasets collect important aggregated data regarding building construction, energy consumption and occupants, and cities are making a significant effort to update spatial referenced data of their territory. However, these data is generally not detailed enough, being available at different scales and in different formats. The integrated use of these data is critical to validate different methods to predict and model energy consumption in cities, as well in addressing its energy saving potential. Furthermore, scenario analysis for retrofit or new design is only possible at building scale, highlighting the potential of a bottom-up database. This paper presents the process of collecting, mapping, cleansing and integrating urban data resulting in an UBD to support an information system for Smart Cities. The goal is to reduce the gap between the available urban data and the specific data required to run a complete urban building energy simulation. Key characteristics of an UBD are explored and applied to a case study in Lisbon, Portugal. As a result, a Buildings Dashboard is developed, materializing the UBD user interface. This dashboard allows the interactive visualization and data exploration of the building stock at multiple scales. Future work includes the development of an Urban Scenario category, bringing new insights on urban energy simulation and scenario evaluation to this platform., The authors acknowledge Fundação para a Ciência e Tecnologia for the financial support of the SusCity project (MITP-TB/CS/0026/2013) through the MIT-Portugal Program and the Post-Doctoral scholarship (SFRH/BPD/96459/2013), and to ADENE, EDP Distribuição, CML, Lisboa E-Nova, INE and Climaespaço, for making their data available for scientific research., info:eu-repo/semantics/acceptedVersion

Providing healthy food for the world’s growing urban population is a recognized global challenge and it is likely that current modes of conventional, large-scale farming will over time be increasingly complemented by local, urban farming practices. Apart from its acknowledged social benefits, urban farming is also widely viewed as a more resource-efficient alternative to conventional remote farming. Especially indoor, soilless cultivation in urban areas is being portrayed as a particularly sustainable solution. However, as this technique relies on controlled environments, its ongoing operation can be quite energy-intensive and related carbon emissions should be carefully weighed against reduced emissions, such as those from transportation. To further this goal, this article presents a simulation-based environmental analysis workflow for Building-Integrated Agriculture (BIA) in urban contexts, that includes detailed solar radiation, water and energy specific models. The aim of the workflow is to guide the user through decision-making on the potentialities of implementing BIA in a given neighborhood while maximizing crop yields and minimizing water and energy consumption. The workflow was applied to three hi-tech urban farming scenarios in Lisbon, Portugal: a polycarbonate Rooftop Greenhouse (RG), a Vertical Farm (VF) with windows and skylights on the top floor of a reinforced-concrete building as well as a completely opaque VF with no penetration of natural light on the ground floor of a reinforced-concrete building. Global Warming Potential (GWP) related to water, transportation and operational energy of these three case studies were compared to GWP of (i) the currently existing supply chain for tomato, and (ii) a hypothetical low-tech unconditioned rooftop urban farm. Results show that the RG and the top floor VF had the best overall environmental performance, respectively cutting greenhouse gas emissions in half and in three in comparison with the existing supply chain for tomato. By allowing this preliminary assessment of alternative farm locations and properties, the workflow provides the user with actionable information for early-stage holistic assessment of BIA projects.

© 2017 The Authors. The necessary simplification of building stock models to perform energy studies in cities can impact their accuracy. This paper assesses the impact of considering different levels of detail in the characterization of the building stock, by varying the number of archetypes considered, using a neighborhood in Lisbon as case-study. Each archetype represents a share of buildings and is defined by the most representative construction parameters and average geometrical characteristics. The results show that while oversimplification might lead to large differences, there is also no need to consider a very detailed characterization of the building stock to obtained consistent results., Massachusetts Institute of Technology. Portugal Program (Grant MITP-TB/CS/0026/2013), Fundação para a Ciência e a Tecnologia (Post-Doctoral Scholarship SFRH/BPD/96459/2013)

Global food systems are as vital for human survival as they constitute a major threat to the environment, being key drivers of climate change, water use, toxic emissions and habitat change. In a business as usual scenario, these impacts will most likely increase, driven by population and economic growth, which will lead to a higher demand for food, and probably for the most environmentally intensive food categories: meat and dairy products. Existing literature suggests deep paradigmatic changes to address this situation, such as (i) large-scale dietary changes on the consumption side, and (ii) structural changes towards more efficient food supply chains on the production side. As both of these measures are related to urban systems, in terms of food consumption habits and the potential of local production, Urban and Peri-Urban Agriculture (UPA) may assume a relevant role in food systems sustainability. In order to estimate to what extent the implementation of UPA would play a role in mitigating the environmental impacts of urban food systems, this paper uses life cycle assessment (LCA) to estimate their respective mitigation potential. The Global Warming Potential (GWP) and Land use (LU) were assessed for per capita Current Average Consumption (CAC) in Lisbon, and this baseline model was subsequently adapted in order to measure the effects of changes: (i) in the diet, through a comparison with the Recommended Healthy Diet (RHD) model; and (ii) in the food supply chain, by measuring the impacts of eliminating losses and wastage across the food supply chain and shortening transportation distances through local food production. The results show that the highest potential for environmental impacts mitigation is related to dietary changes. However, strategies for enhancing the efficiency of the food supply chain are relevant, as reducing losses and wastage, shortening transportation distances and taking into account technology improvements can further increase the mitigation potential.

District heating networks are commonly assumed in the literature as an environmentally friendly solution for providing heating services for the built environment, due to the centralized heat production located outside urban centers and potential utilization of renewable heat sources (solar, geothermal etc.). However, the impacts associated with both construction and operation phases are frequently overlooked. The main scope of this paper is to make use of the emergy approach to infer environmental performance of the heat provided by district heating networks, considering two types of district heating systems: ESPEX (four-pipe network) and traditional two-pipe district heating network. For centralized heat production, three options were considered: central boiler fueled by fossil fuel mix, natural gas, and solar plant. Additionally, a natural gas distribution network with individual gas boiler in each dwelling was considered. An emergy evaluation was performed to enable the comparison of these systems on the same basis. All systems were applied to the district of Vraen, located in Varnamo, Sweden. The overall results showed that four-pipe ESPEX district heating network with central solar plant is the most suitable solution from the emergy point of view. The second most suitable solution was the two-pipe district heating network with solar plant as the heat production unit. On the other hand, networks with central boiler that used the fuel mixture (bioethanol and fossil fuels) and natural gas had lower environmental performance than the natural gas distribution network with individual boiler in each dwelling.

This paper characterizes municipal solid waste (MSW) management practices in developing Asia, with a focus on low and middle-income countries. The analysis that is conducted supports a proposed framework that maps out the trends observed in the region in relation to two parameters, waste compositions and urban dimension, which was prepared based on a set of national and urban case studies. The management of MSW in developing Asian countries is driven, first and foremost, by a public health imperative: the collection and disposal of waste in order to avoid the spread of disease vectors from uncollected waste. This comes, however, at a high cost, with local government authorities in these countries spending up to 50% of their budgets in the provision of these services. Little or no value is derived from waste, which is typically seen as a liability and not as a resource that can be harnessed. On the other hand, in many cities in developing Asia there is an informal sector that ekes out a living from the recovery of recyclable materials found in waste. Members of this "informal waste sector" are especially active in areas that are not served by formal waste collection systems, such as slums or squatter areas. A distinctive element shared among many cities in developing Asian countries concerns the composition of the municipal solid waste. MSW in those countries tends to be richer in biodegradable organic matter, which usually accounts for more than 50% of the total waste composition, suggesting that biological methods are more appropriate for treating this organic fraction. Conversely, thermal combustion technologies, which are extensively applied in high-income countries, are technically and economically challenging to deploy in light of the lower calorific value of waste streams which are rich in organics and moisture. Specific approaches and methods are therefore required for designing adequate waste management systems in developing Asian countries. In addition, despite some common characteristics shared among cities in developing Asia, their specific circumstances can significantly vary, even within the same country, calling for the need for context-specific waste management approaches. Set against this background, this paper proposes a guiding framework in the form of a matrix that maps out approaches observed in the management of municipal solid waste in cities of developing Asian countries as a function of the city dimension, share of organics on waste streams, and wealth generated by the city. The cities of Surabaya (Indonesia), Bangalore (India), Quy Nhon (Viet Nam), and Matale (Sri Lanka) are showcased as good practices in the region in the management of solid waste, with their experiences used to illustrate the framework laid out in the matrix.

Urban metabolism provides a characterization of anthropogenic material flows in urban systemsand should contribute to identify the economic activities that were involved on their supply andtransformation. Typically, its quantification requires data that is not easily available in differentgeographies. This paper makes use of a methodology based on monetary input–output tables andinternational trade statistics that might be easily replicable to many metropolitan areas in theworld, and which is intended to provide a first rough estimation of urban material flows.The paper discusses the results obtained for four metropolitan areas (Lisbon, Paris, Seoul–Incheonand Shanghai), assessing the material requirements of these economies. The urban areas arecompared in terms of the quantity and the type of material input, destination of materials withinthe economy and their distribution among economic activities. The results showed that whileLisbon is the most diverse urban area in terms of the consumption of material types, it is also theurban area with the least diversified manufacturing sector.The application of this methodology to several urban areas and across multiple years enables theassessment of the technological and economic evolution of those regions

The challenges brought on by the increasing complexity of electronic products, and the criticality of the materials these devices contain, present an opportunity for maximizing the economic and societal benefits derived from recovery and recycling. Small appliances and computer devices (SACD), including mobile phones, contain significant amounts of precious metals including gold and platinum, the present value of which should serve as a key economic driver for many recycling decisions. However, a detailed analysis is required to estimate the economic value that is unrealized by incomplete recovery of these and other materials, and to ascertain how such value could be reinvested to improve recovery processes. We present a dynamic product flow analysis for SACD throughout Portugal, a European Union member, including annual data detailing product sales and industrial-scale preprocessing data for recovery of specific materials from devices. We employ preprocessing facility and metals pricing data to identify losses, and develop an economic framework around the value of recycling including uncertainty. We show that significant economic losses occur during preprocessing (over $70 M USD unrecovered in computers and mobile phones, 2006-2014) due to operations that fail to target high value materials, and characterize preprocessing operations according to material recovery and total costs.

This paper investigates the economic adoption of microgrids, focusing especially on community-scale systems. Feasibility analysis results in the case study countries Portugal and Japan, as well as sensitivity analyses to various grades of change in demand factors such as customer mix, demand characteristics, and the uncertainty of end-use demand, are presented. The results show that the characteristics of the demand are at the heart of microgrids financial attractiveness. High values of HPR and HEC unlock energy efficiency opportunities linked to CHP, while high load factors allow DG to more appropriately run within their operational constraints. Also, generally, community microgrids form more attractive investments than single microgrids, and can be specifically designed for optimal financial performances. Single microgrids are sensitive to demand oscillations, while community microgrids are more resilient, taking various levels of variability while still running economically. Finally, an overview of legal and regulatory challenges that community microgrids face and that emerged as learnings from this research is also introduced.

Summary Under an extended producer responsibility (EPR) system, when a producer delivers a product to the market it must also pay a takeback fee, which is used to cover the costs of end-of-life disposal. EPR systems are currently used in Europe and beyond to manage a variety of products, including packaging and used tires. In this article we develop an input-output (IO) model that is able to assess the impacts of an EPR system, and is based on the waste IO (WIO) model. The WIO model is itself a hybrid-unit model extension of the Leontief model that is able to capture the substitution effect between recycled/recovered material/energy from waste treatment and their non-waste cognates. The resulting EPRIO model, besides the conventional direct and indirect effects of the Leontief model and the substitution effects of the WIO model, is able to capture the opportunity costs of financing the EPR system, and additionally requires the specification of an alternative waste management policy, with its own opportunity costs. The impact of an EPR policy is thus the difference between the impacts of the reference EPR and the alternative waste treament policies. The resulting model is illustrated with a simple example of a used tire management EPR system.

Incomplete recovery of materials in mobile phones results in a significant economic loss. Many studies have focused on improving the situation by characterizing metals within printed circuit boards (PCBs) to identify where losses occur. Our work focuses on the evolving composition of mobile phones and particularly the flow of materials located within components outside of PCBs. In this study we quantify the appreciable economic potential of non-PCB derived metals and provide suggestions for optimization of different preprocessing steps to recover these materials. These opportunities can be categorized as recovering both high value and high volume materials. We therefore recommend that preprocessors pay special attention to precious metals in fine shredding and develop strategies for plastics recycling based on our demand and supply forecasts of postconsumer plastics in phones. We have performed this work based on a case study of Portugal.

Approximately 30–40% of the total natural resources that are used in industrialized countries are exploited by the building sector, and almost 40% of the world’s consumption of materials converts into the built environment. Thus, improving the environmental performance of building sector could be crucial for reaching the sustainability of urban environment. The main scope of this paper is to highlight the interest of building renovation as an adequate measure for improving building environmental performance in term of emergy and identify processes that cause significant environmental stress on a local ecosystem. To enable the comparison of all phases and processes for the studied system, an emergy evaluation was performed. A multi-apartment building located in the city of Sabac, Serbia, was used as case study. Several building renovation scenarios were considered, which include different measures for building envelope thermal performance improvements, as well as installation of local renewable energy heat production system. Different renovation timelines were also compared. The overall results showed that 68% of the emergy flow is caused during the building operation phase, 24% during the construction phase and only 8% during the end-of-life phase. All renovation measures proved to be beneficial from the environmental point of view, and the use of additional materials and resources to conduct renovation measures considered did not have a negative impact on the building overall environmental performance. The effect of conducting renovation measures after the first decade of building lifetime improved the overall building environmental performance by almost 50% when compared to the same renovation measures conducted in the last decade of the lifetime (for all measures considered). Finally, based on the emergy indices analysis, it can be concluded that the application of building renovation measures improves the overall building environmental performance, enables higher efficiency in indigenous resource use, and lowers the pressure on a local ecosystem.

Heat demand may decrease in the future due to changing weather conditions and building renovation policies, possibly impacting the efficiency and profitability of renewable heat production and distribution systems which are commonly proposed in the literature as an adequate measure for building sector emissions mitigation. In this work, the potential evolution of building heat demand in characteristic locations (within heating dominant climates) is assessed for different scenarios by using a sample building as a case study. Three future weather scenarios were created based on a previously developed methodology, along with one building renovation scenario based on market penetration rates of different renovation measures. Heat demand was calculated through a heat demand model previously developed and validated by the authors. To represent the results, heat demand-outdoor temperature function parameters were used. The results indicated that the impact of changed weather conditions was significantly lower than the impact of building renovation. Overall, the difference in the parameters rate of decrease/increase was lower than 2% between weather scenarios for the same year considered. After the initial building renovation in 2020, the slope coefficient of the outdoor temperature-heat demand function increased between 45% and 51%, while the intercept decreased within the range of 48% and 51% (depending on the weather scenario and location considered). The reduction in the number of heating hours was almost negligible in the colder climates considered, while in the warmer climates the decrease rate was significant – 0.8% and 43% of heating hours respectively in 2050 compared to 2010, for the medium weather scenario. Such decrease in demand and heating hours could significantly impact the operational parameters of heat production and distribution units, as well as their feasibility.

District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand – outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.

In the last years the electricity industry has faced a restructuring process. Among the aims of this process was the increase in competition, especially in the generation activity where firms would have an incentive to become more efficient. However, the competitive behavior of generating firms might jeopardize the expected benefits of the electricity industry liberalization. The present paper proposes a conjectural variations model to study the competitive behavior of generating firms acting in liberalized electricity markets. The model computes a parameter that represents the degree of competition of each generating firm in each trading period. In this regard, the proposed model provides a powerful methodology for regulatory and competition authorities to monitor the competitive behavior of generating firms. As an application of the model, a study of the day-ahead Iberian electricity market (MIBEL) was conducted to analyze the impact of the integration of the Portuguese and Spanish electricity markets on the behavior of generating firms taking into account the hourly results of the months of June and July of 2007. The advantages of the proposed methodology over other methodologies used to address market power, namely Residual Supply index and Lerner index are highlighted.

The European Union proposed the introduction of taxes on emitted CO2 as an effective policy measure for the reduction of CO2 emissions in its electricity sector. Applying the TIMES (The Integrated MARKAL-EFOM System) modeling tool, this paper examines the cost effectiveness of different evolutions of CO2 taxes under the Emissions Trading System in Europe by 2050 in order to analyze the possible roles and limits of different mitigation technologies within the Portuguese electricity supply system. The results were analyzed based on the final year CO2 emissions of the electricity system when compared to 1990 levels. The results show that when CO2 prices stay below 50 €/tonne by 2050 there is no reduction in emitted CO2 emissions when compared to the levels of 1990. For CO2 prices reaching between 50 and 100 €/tonne there is a clear reduction in CO2 with the increase in the price, from 7% with 50 €/tonne to 79% with 100 €/tonne. For prices above 100 €/tonne the increased taxation has only a slight impact on the reduction of CO2 emissions, as even with a 300 €/tonne price the CO2 reductions achieved are only of 87%.

The impact of the management of packaging waste on the environment, economic growth and job creation is analyzed in this paper. This integrated assessment intends to cover a gap in the literature for this type of studies, using the specific case study of the Portuguese packaging waste management system (SIGRE). The net environmental benefits associated with the management of packaging waste, are calculated using the Life Cycle Assessment methodology. The results show that, for the categories studied, the impacts associated to SIGRE's various activities are surpassed by the benefits associated to material and energy recovery, with special focus on recycling. For example, in 2011 SIGRE avoided the emission of 116 kt CO2 equiv. – the equivalent carbon emission of the electricity consumption of 124.000 households in Portugal. The economic impact of SIGRE is evaluated through Input–Output Analysis. It was found that SIGRE's activities also have a significant economic impact. For example, their added value are ranked amongst the upper third of the economic activities with highest multiplier effect at national level: this means that for each Euro of value added generated within SIGRE, 1.25 additional € are added to the rest of the economy (multiplier effect of 2.25). Regarding the social impacts of SIGRE, the number of direct jobs associated with the system is estimated to be more than two thousand and three hundred workers. Out of these, 83% are connected to the management of municipal waste packaging (selective collection and sorting), 15% are connected to the management of non-municipal packaging waste and only 2% are connected to the Sociedade Ponto Verde (SPV, green dot society in English) – the management entity responsible for SIGRE. In general terms, the results obtained provide quantitative support to the EEA (2011) suggestion that moving up the waste hierarchy – from landfilling to recycling – creates jobs and boosts the economy.

The increase of fossil fuel demand raises concerns on availability of resources for future energy demand and on potential environmental impacts. Electric vehicles (EVs) appear as one alternative to shift from fossil fuels to renewable energy resources. This research work analyzes the benefits of the introduction of EVs in a small energy system, the Flores island, Azores, in terms of primary energy and CO2 emissions. Four scenarios were designed considering different penetration rates of EVs (Low and High) and different time of recharging strategies (Fixed and Flexible). The high shares of RES in the electricity production system (60–62%) did not guarantee a significant use of RES for the recharging of EVs (10–40%), as the additional electricity required had to be produced mainly from the diesel generators. The flexible recharging strategies allowed doubling the share of RES in the recharging of the EVs when compared to fixed recharging, and consequently double the impact on the reduction of primary energy consumption and fossil fuels imports. While the reduction of primary energy ranged between 0.2% and 1.1%, for CO2 emissions there was a decrease between 0.3 and 1.7%, proving that EVs can help improve the sustainability of energy systems.

This article provides an assessment of waste management evolution in Portugal, with a particular emphasis on the performance brought by the adoption of several EPR schemes, namely the ones developed for packaging (general, medicine and plant protection products), used tires, used mineral oils, end-of-life vehicles (ELV), waste electrical and electronic equipment (WEEE), portable batteries and car and industrial batteries. Further, a particular focus is placed on the drivers that influenced the development of such EPR schemes in the country and the challenges facing EPR schemes' development in Portugal. The results achieved in a short period of time suggest that the evolution of the implementation of the EPR concept in Portugal was, so far, successful, not only in quantitative but also in qualitative terms (contributing for a reduction of environmental performance). However, there is still room for improving EPR impact in the long-run and this is largely dependent on policy instruments (of fiscal, information and supervision natures) that can positively influence the context in which EPR schemes operate.

Summary: This article describes a new methodological framework to account for urban material flows and stocks, using material flow accounting (MFA) as the underlying method. The proposed model, urban metabolism analyst (UMAn), bridges seven major gaps in previous urban metabolism studies: lack of a unified methodology; lack of material flows data at the urban level; limited categorizations of material types; limited results about material flows as they are related to economic activities; limited understanding of the origin and destination of flows; lack of understanding about the dynamics of added stock; and lack of knowledge about the magnitude of the flow of materials that are imported and then, to a great extent, exported. To explore and validate the UMAn model, a case study of the Lisbon Metropolitan Area was used. An annual time series of material flows from 2003 to 2009 is disaggregated by the model into 28 material types, 55 economic activity categories, and 18 municipalities. Additionally, an annual projection of the obsolescence of materials for 2010-2050 was performed. The results of the case study validate the proposed methodology, which broadens the contribution of existing urban MFA studies and presents pioneering information in the field of urban metabolism. In particular, the model associates material flows with economic activities and their spatial location within the urban area.

The large scale penetration of electric vehicles (EVs) will introduce technical challenges to the distribution grid, but also carries the potential for vehicle-to-grid services. Namely, if available in large enough numbers, EVs can be used as a distributed energy resource (DER) and their presence can influence optimal DER investment and scheduling decisions in microgrids. In this work, a novel EV fleet aggregator model is introduced in a stochastic formulation of DER-CAM [1], an optimization tool used to address DER investment and scheduling problems. This is used to assess the impact of EV interconnections on optimal DER solutions considering uncertainty in EV driving schedules. Optimization results indicate that EVs can have a significant impact on DER investments, particularly if considering short payback periods. Furthermore, results suggest that uncertainty in driving schedules carries little significance to total energy costs, which is corroborated by results obtained using the stochastic formulation of the problem.

The design of transition pathways for sustainable electricity systems with high penetrations of renewable energy sources requires the use of energy modeling tools that are able to account for two key aspects: the evolution of fossil fuels and technology prices, and the natural dynamics of renewable resources. However, the modeling methodologies most currently used focus on only one of these two aspects, which hinders their suitability for performing long-term analysis with high penetrations of renewable energy sources. This paper presents a modeling framework that is able to optimize the investment in new renewable generation capacity on the long-term while taking into account the hourly dynamics of electricity supply and demand. The framework combines two of the most used energy planning tools, each able to account for one of the aspects of the modeling of energy systems. The framework was applied to continental Portugal for the time period of 2005–2050, in order to identify optimal investment plans in new renewable and fossil generation capacity with the goal of achieving significant CO2 emissions reduction, under different scenarios. The results show that the inclusion of dynamics in the modeling methodology can help avoid overinvestment and reduce the excess of electricity from renewable energy sources that cannot be used by the system. These results can have a significant impact on the design of a sustainable electricity system and may lead to a diversification of the energy sources used.

This paper describes the introduction of stochastic linear programming into Operations DER-CAM, a tool used to obtain optimal operating schedules for a given microgrid under local economic and environmental conditions. This application follows previous work on optimal scheduling of a lithium-iron-phosphate battery given the output uncertainty of a 1 MW molten carbonate fuel cell. Both are in the Santa Rita Jail microgrid, located in Dublin, California. This fuel cell has proven unreliable, partially justifying the consideration of storage options. Several stochastic DER-CAM runs are executed to compare different scenarios to values obtained by a deterministic approach. Results indicate that using a stochastic approach provides a conservative yet more lucrative battery schedule. Lower expected energy bills result, given fuel cell outages, in potential savings exceeding 6percent.

The management of municipal solid waste (MSW) is one of the main costs incurred by local authorities in developing countries. According to some estimates, these costs can account for up to 50% of city government budgets. It is therefore of importance that policymakers, urban planners and practitioners have an adequate understanding of what these costs consist of, from collection to final waste disposal. This article focuses on a specific stage of the MSW value chain, the treatment of waste, and it aims to identify cost patterns associated with the implementation and operation of waste treatment approaches in developing Asian countries. An analysis of the capital (CAPEX) and operational expenditures (OPEX) of a number of facilities located in countries of the region was conducted based on a database gathering nearly 100 projects and which served as basis for assessing four technology categories: composting, anaerobic digestion (AD), thermal treatment, and the production of refuse-derived fuel (RDF). Among these, it was found that the least costly to invest, asa function of the capacity to process waste, are composting facilities, with an average CAPEX per ton of 21,493 USD2015/ton. Conversely, at the upper end featured incineration plants, with an average CAPEX of 81,880 USD2015/ton, with this treatment approach ranking by and large as the most capital intensive of the four categories assessed. OPEX figures of the plants, normalized and analyzed in the form of OPEX/ton, were also found to be higher for incineration than for biological treatment methods, although on this component differences amongst the technology groups were less pronounced than those observed for CAPEX. While the results indicated the existence of distinct cost implications for available treatment approaches in the developing Asian context, the analysis also underscored the importance of understanding the local context asa means to properly identify the cost structure of each specific plant. Moreover, even though CAPEX and OPEX figures are important elements to assess the costs of a waste treatment system, these should not be considered on a standalone basis for decision making purposes. In complement to this internal cost dimension, the broader impacts - to the economy, society and the environment - resulting from the adoption of a certain treatment approach should be properly understood and, ideally, measured and expressed in monetary terms.

This work assesses the retrofit potential of existing Portuguese fossil fuel power plants with post-combustion CO2 capture and storage (CCS) technology. The Integrated Environmental Control Model (IECM) was used to provide a systematic techno-economic analysis of the cost of emission control equipment, the reduction in greenhouse gas emissions, and other key parameters which may change when CCS is implemented at a fossil fuel power plant. The results indicate that CCS requires a large capital investment and significantly increases the levelized cost of electricity. However, the economic viability of CCS increases with higher CO2 prices. The breakeven CO2 price for plants with and without CCS was estimated at $85–$140/t of CO2 depending on the technical parameters of the individual plants.

Increasing levels of intermittent renewables, especially wind power, in energy systems require accurate temporal characterisation of the resources’ availability at seasonal, daily and hourly scales. This is crucial for isolated energy systems, where increasing wind power penetration is limited due to costly backup power generation requirements. In the case studies presented in this paper, the energy systems of two islands are simulated using a new methodology for synthetic wind speed scenarios including daily wind patterns. A trade-off analysis was conducted in terms of surplus wind power and renewables penetration rate, with the objective of supplying decision support on wind turbine placement. Results show that there may be a significant advantage in locating future wind parks on sites where wind speed patterns better match electricity demand patters, rather than just choosing a site with the highest mean wind speed, but only if the annual mean wind speed is still sufficiently high to make the investment economically feasible.

The annual electricity consumption on the Alameda Campus of Instituto Superior Tecnico (IST), University of Lisbon, was around 14 GWh with a 1 MW base load, between 2006 and 2010. With the purpose of improving the overall energy efficiency within IST facilities, the “Sustainable Campus at Tecnico” project was set in motion in 2012 as part of an energy management policy, which engaged different skills across the IST community. This paper describes the key activities carried out by staff, faculty, students and researchers, under the IST Energy Initiative. These encompassed energy and water usage audits, as well as the development of new auditing tools and thermal computational models of all campus buildings, the classification of activity indexes, occupancy levels and the installation of energy meters designed and manufactured by IST researchers. The implementation of no-cost energy conservation measures comprised awareness-raising and best practice adoption with the participation of operations and maintenance staff. Technical operations personnel have been given guidelines on energy-saving measures, and the remaining campus staff was encouraged to participate in energy and water-conservation activities. Measures to improve on-campus energy efficiency included the application of sun control window film in both glazed towers of the campus, as a consequence of the energy-saving estimates evidenced by computational simulations. The results achieved so far, which are explained in detail in this paper, show a significant decrease in electricity consumption, from 14 to 11.5 GWh, and a decrease from 1000 to 850 kW base load, which represents almost 20 % in energy savings, for the same level of service.

The Smart Campus is a European project based in four pilots located in Helsinki (Metropolia University), Lisbon (Instituto Superior Tecnico), Lulea (Technology University) and Milan (Politecnico di Milano), having engaged 76,000 users since August 2012 during 33 months. The main objective of this project was to demonstrate the central role of Information and Communication Technology (ICT) based services that act upon Energy Management Systems and control heating, ventilation and air conditioning (HVAC) and Lighting on achieving energy efficiency through dynamically negotiating building environmental conditions with the users on the University pilots. This paper presents the energy saving results and the best practices obtained in the Lisbon Pilot where ICT equipment was installed in a Library, a lecture Amphitheater and a set of offices. Overall savings were almost 40 % in some test locations. It was observed that energy savings were different between test locations due to particularities such as space typology, occupation and utilization patterns, equipment installed, HVAC and lighting control systems and users interaction.

Changed weather conditions (increased outdoor air temperatures and solar radiation levels) caused by the climate change could decrease building heat demand in the future. Furthermore, improved building insulation levels implemented due to the new building energy efficiency legislation could further decrease the demand for heating services. The main scope of this study is to present a methodology to assess the possible long-term effects of climate change on building heat demand on a large scale. A building heat demand model based on the thermoelectricity analogy was developed within this study, which is capable to take into account all relevant weather (outdoor air and solar radiation) and building (geometry, thermal properties etc.) parameters. The model was verified through the comparison with Design Builder v4.6. (Energy Plus v.8.3), with satisfactory outcome (average percentage error in annual heat demand of 4.47% and standard deviation between the hourly heat demand values of 2.73), and then applied on the district of Alvalade located in Lisbon (Portugal). Three weather scenarios were developed (low, medium, high temperature and solar radiation increase) along with three district renovation scenarios (shallow, intermediate, deep). For the representation of the results, district heat demand density and heat demand slope coefficient (slope of the heat demand—outdoor temperature function) were used. The results suggest that heat demand density could decrease within the range of 22.3–52.4% in 2050 compared to 2010, depending on weather and renovation scenario studied. Accordingly, the heat demand slope coefficient increases within the range of −1.79 W/°C to −1.43 W/°C. However, even with all the heat demand reductions, the district still remains feasible for district heating (with heat demand density higher than 50 GWh/km2/yr for all studied scenarios).

Recognizing habitual behavior and providing feedback in context are key to empower individuals to take control over residential electricity consumption. Yet, it is a challenge to change habitual behavior, embedded in everyday routines. This paper intends to discover whether habitual behavior can be identified by pattern recognition techniques. The data source is an experiment similar to a utility led advanced metering infrastructure implementation. The analysis discovers: (1) persistent daily routines and (2) patterns of consumption or baselines typical of specific weather and daily conditions. Approximately 80% of household electricity use can be explained within these two patterns, with several applicable “profiles” for this population, including: unoccupied baseline, hot working days, temperate working days, cold working days, and cold weekend days. The proposed methodology demonstrates that it is possible to use pattern recognition methodologies to recognize habitual electricity consumption behavior given the intrinsic characteristics of the family. This approach could be useful to improve small scale forecast, and as a mechanism to enable the provision of tailor-made information to the families.