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Although the relationship between renewable energy and economic performance has attracted the interest of researchers in recent years, most of the analysis has focused on economic growth, which does not reflect the quality of standards of living. We employ a different approach measuring the impact of renewable energy consumption on the Human Development Index, which also considers qualitative characteristics. Using a simultaneous equation system approach that describes the interrelations between economic variables, renewable energy and pollution emissions with feedback effects, we provide robust evidence for a set of 28 OECD countries over the period 2004-2015, that renewable energy, human and physical capital are important factors for explaining the degree of sustainable development. Renewable energy consumption is mostly determined by higher levels of human capital, R&D, and the countries’ development stage. Furthermore, the development level, total energy consumption, and the education level are important for explaining environmental pollution.

Photocatalytic oxidation is promising technology for removal of recalcitrant pollutants from water. Solar energy can be an interesting radiation source since the operating costs can be lower. However, the use of powder photocatalyst is a major drawback of the technology since suitable separation technologies are required and catalysts recovery is difficult. This work aims to test the suitability of using polymeric supports to immobilize TiO 2 in the reactor and apply it for parabens removal from water by solar photocatalytic oxidation. Polyurethanes (PU) and polydimethylsiloxane (PDMS) membranes were prepared and modified with TiO 2. While PU materials are only able to adsorb (35% in 1 h) parabens whichever the modification applied, modified PDMS was able to promote parabens photocatalytic oxidation removing 20% in 1 h under solar energy. Plasma/UV modification was able to active PDMS membranes (16% of methyl paraben (MP) removal) and further entrapment of TiO 2 in the polymeric matrix did not improve the process (18% of MP removal). Thus, only the superficial TiO 2 was active. Results show that PDMS is suitable material to support TiO 2 aiming photocatalytic wastewater treatment process using the Sun as a clean and renewable energy source.

This article presents an assessment of the most suitable compressed air energy storage (CAES) reservoirs and facilities to better integrate renewable energy into the electricity grid. The novelty of this study resides in selecting the best CAES reservoir sites through the application of a multi-criteria decision aid (MCDA) tool, specifically the simple additive weighting (SAW) method. Besides using geographic information systems (GIS) spatial representation of potential reservoir areas, for the MCDA method, several spatial criteria, environmental and social constraints, and positive incentives (e.g., the proximity to existing power generation facilities of renewable energy sources) were contemplated. As a result, sixty-two alternatives or potential reservoir sites were identified, and thirteen criteria (seven constraints and six incentives) were considered. The final stage of this study consisted of conducting a sensitivity analysis to determine the robustness of the solutions obtained and giving insights regarding each criterion’s influence on the reservoir sites selected. The three best suitable reservoir sites obtained were the Monte Real salt dome, Sines Massif, and the Campina de Cima—Loulé salt mine. The results show that this GIS-MCDA methodological framework, integrating spatial and non-spatial information, proved to provide a multidimensional view of the potential reservoir CAES systems incorporating both constraints and incentives.

Dissertação de Mestrado em Energia para a Sustentabilidade apresentada à Faculdade de Ciências e Tecnologia O setor de energia é fundamental para o desenvolvimento sustentável. Manter os níveis de atividade econômica enquanto reduz-se o consumo de eletricidade é um dos principais desafios a ser superado.Neste contexto, a intensidade elétrica é um indicador chave na avaliação da eficiência econômica por ser uma medida da produção da economia relacionada à eletricidade demandada. No entanto, a análise simplista do índice de intensidade elétrica não é muito reveladora, uma vez que os desvios neste índice são resultado de mudanças nos seus diferentes componentes. Desta forma, o objetivo desta dissertação é abordar detalhadamente a influência destes componentes, decompondo o indicador de intensidade elétrica na União Europeia.Complementando o método logarithmic mean Divisia index (LMDI) introduzido por Ang (2015), é proposta uma atualização que decompõe o componente de intensidade e adiciona um novo elemento à metodologia de decomposição. Consequentemente, os componentes da intensidade elétrica são três: estrutura, eficiência e eletrificação. Este aprimoramento, inovador de acordo com o nosso conhecimento, é fundamental para distinguir a real influência do componente de eficiência dos outros elementos, considerando que as metas de eficiência energética têm se tornado mais rigorosas e precisam ser perfeitamente mensuradas.Os resultados da decomposição atualizada demonstraram que o impacto causado pelo componente de eficiência foi, na verdade, maior do que aparentava. Se houvesse apenas melhorias de eficiência energética e, simultaneamente, nenhuma mudança na estrutura econômica e na taxa de eletrificação, o índice de intensidade elétrica teria diminuído 48,64% entre 1995 e 2017, valor 8,75% maior ao que realmente ocorreu.O fator estrutural apresentou menor influência na intensidade elétrica, embora o setor de serviços tenha aumentado a sua participação em 5,12% e a estrutura econômica da UE tenha mudado. Adicionalmente, o componente de eletrificação contribuiu para aumentar o indicador de intensidade, já que o consumo de eletricidade cresceu a taxa superior à produção econômica.Por fim, uma análise particionada demonstrou que a redução na intensidade elétrica foi causada exclusivamente por melhorias de eficiência no ciclo 2012-2017, sugerindo evidências positivas a respeito do sucesso das medidas de eficiência energética na UE. The energy sector is fundamental for sustainable development. Maintaining high levels of economic activity while reducing electricity consumption is still one of the main challenges to overcome.In this context, electricity intensity is a key indicator in assessing the economic efficiency because it is a measure of the economy output related to the electricity demanded. However, a simplistic analysis of the electricity intensity index does not reveal much, since the deviations in this indicator are the result of changes in its different components. Therefore, the objective of this dissertation is to address these components influence in detail, decomposing the electricity intensity indicator in European Union.Complementing the logarithmic mean Divisia index (LMDI) method introduced by Ang (2015), an upgrade is proposed, by breaking down the intensity component and adding a new element to the decomposition methodology. Consequently, the components of the electricity intensity are three: structure, efficiency and electrification. This enhancing feature, innovative to the best of our knowledge, is fundamental in distinguishing the real influence of the efficiency component from other elements, considering that energy efficiency goals are becoming more stringent and have to be perfectly measured.Results from the upgraded decomposition demonstrated that the impact caused by the efficiency component was, in fact, greater than it appeared. If there had been merely improvements in energy efficiency, and simultaneously no changes neither in the economic structure, nor in the electrification rate, the electricity intensity index would have decreased 48.64% from 1995 to 2017, a result 8.75% greater than what actually occurred.The structural factor displayed minor influence in electricity intensity, even though the service sector increased its shared by 5.12% and the economic activity profile of EU has changed. Additionally, the electrification component contributed to increase the intensity indicator, since the electricity consumption has grown at a higher rate than the economy output.Finally, a partitioned analysis demonstrated that the reduction in electricity intensity was solely caused by efficiency improvements in the 2012-2017 cycle, suggesting positive evidence regarding the success of energy efficiency measures in the EU.

Moving towards a global bioeconomy can mitigate climate change and the depletion of fossil fuels. Within this context, this work applies a set of multi-criteria decision analysis (MCDA) tools to prioritise the selection of five alternative bioenergy systems for residential heating based on the combination of three commercial technologies (pellet, wood stove and traditional fireplace) and two different feedstocks (eucalypt and maritime pine species). Several combinations of MCDA methods and weighting approaches were compared to assess how much results can differ. Eight indicators were used for a sustainability assessment of the alternatives while four MCDA methods were applied for the prioritisation: Weighted Sum Method (WSM), Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), Elimination and Choice Expressing Reality (ELECTRE), and Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE). Regarding the sustainability performance indicators, the highest environmental impacts were calculated for the fireplace alternatives, and there was not a best environmental option. Also, no clear trend was found for the economic and social dimensions. The application of MCDA tools shows that wood stove alternatives have the best sustainability performance, in particular wood stove with combustion of maritime pine logs (highest scores in the ranking). Regarding the worst alternative, fireplaces with combustion of eucalypt logs ranked last in all MCDA rankings. Finally, a sensitivity analysis for the weighting of the performance indicators confirmed wood stoves with combustion of maritime pine logs as the leading alternative and the key role of the analysts within this type of MCDA studies.

Abstract Given the importance of renewable energy in the discussion of a reliable and sustainable energy future, it is imperative to understand its main determinants and to draw result implications for energy policy. This study analyses these determinants for Sub-Saharan Africa. Using a panel data technique, namely the panel-ARDL model for a period covering 1990–2014, the results suggest that economic development (per capita GDP) and an increased use of energy aid renewable energy development while population growth impedes it. Furthermore, the study investigates the potentials and current status of renewable energy in Sub-Saharan Africa. This article shows that although the region has great potential for developing renewable energy such as wind, biomass, solar and hydropower, dispersed throughout the continent, this potential has not been fully explored, even though many resources are plentifully available, and evidence good economic potential.

The Moving Bed Biofilm Reactor (MBBR) system is considered an Advanced Wastewater Treatment (AWT), which combines the best of Conventional Activated Sludge (CAS) and biofilter processes, making use of suspended biomass and attached biomass. This system requires less space than CAS to process the same amount of wastewater and can be adapted to the existing structures of CAS. The dairy wastewater obtained during the milk transformation and cleaning operations is a residue characterized by a high content of organic matter and hydrocarbon compounds which contribute to its biodegradability, normally allowing the use of biological processes for the treatment of these effluents. In this study, the performance of the MBBR at a lab-scale during batch and continuous operations was addressed while changing the Organic Load (OL), the Filling Ratio (FR) and the Hydraulic Retention Time (HRT). The MBBR shows to be more stable when a FR of 40% is used, which allows a reduction of the HRT from 8 to 4 h, reaching a COD removal of 95%, allowing a reduction on the energy consumption, compared to the conventional processes.

Abstract The aim of this paper is to demonstrate how integrated resource planning (IRP) oriented to the gas sector can be applied both in new networks and in mature networks, and to present the advantages of its application. One case study is described, in the western central region of Portugal, to illustrate the results of a pilot project on natural gas IRP implementation in a new network in the European Union (EU). The city of Burg, Germany, with a mature gas network with district heating was also analysed in terms of IRP potential. The most important phases of the integrated resource plan definition and implementation (especially those oriented to the demand-side) are presented, namely, the definition of the most efficient technologies (including solar energy), fuel-switching possibilities, a detailed study of the impacts in the economy, environment and society, and the policy incentives necessary to motivate the gas utility companies to perform IRP. In the main case study, the suggested implementation plan would lead to a reduction of around 4.7% in natural gas consumption. Additionally, 13.3% of cost-effective fuel switching from other competing forms of energy to natural gas can be achieved. A proposed EU energy services directive on mandatory energy–efficiency activities for gas and electricity distribution utilities in the EU, will promote the large-scale implementation of the proposed approach in Europe.

SARS-CoV-2 emerged in late 2019. Since then, it has spread to several countries, becoming classified as a pandemic. So far, there is no definitive treatment or vaccine, so the best solution is to prevent transmission between individuals through social distancing. However, it is not easy to measure the effectiveness of these distance measures. Therefore, this study uses data from Google COVID-19 Community Mobility Reports to understand the Portuguese population’s mobility patterns during the COVID-19 pandemic. In this study, the Rt value was modeled for Portugal. In addition, the changepoint was calculated for the population mobility patterns. Thus, the mobility pattern change was used to understand the impact of social distance measures on the dissemination of COVID-19. As a result, it can be stated that the initial Rt value in Portugal was very close to 3, falling to values close to 1 after 25 days. Social isolation measures were adopted quickly. Furthermore, it was observed that public transport was avoided during the pandemic. Finally, until the emergence of a vaccine or an effective treatment, this is the new normal, and it must be understood that new patterns of mobility, social interaction, and hygiene must be adapted to this reality.

Abstract This paper proposes a new approach to deal with the problem of building national energy efficiency (EE) plans, considering multiple objectives instead of only energy savings. The objectives considered are minimizing the influence of energy use on climate change, minimizing the financial risk from the investment, maximizing the security of energy supply, minimizing investment costs, minimizing the impacts of building new power plants and transmission infrastructures, and maximizing the local air quality. These were identified through literature review and interaction with real decision makers. A database of measures is established, from which millions of potential EE plans can be built by combining measures and their respective degree of implementation. Finally, a hybrid multi-objective and multi-criteria decision analysis (MCDA) model is proposed to search and select the EE plans that best match the decision makers’ preferences. An illustration of the working mode and the type of results obtained from this novel hybrid model is provided through an application to Portugal. For each of five decision perspectives a wide range of potential best plans were identified. These wide ranges show the relevance of introducing multi-objective analysis in a comprehensive search space as a tool to inform decisions about national EE plans.