• Energy Research

Abstract The envelope shape, the most salient design characteristic in a building, has significant influence on its energy performance. However, in the early design stages, when the envelope shape is defined, energy performance information is normally nonexistent, due to modeling for energy simulation being a time-consuming task, frequently overlooked at this phase. This paper presents a methodology to assist design decisions regarding the building envelope shape considering its implications on energy performance. Basically, this methodology involves a flexible design system, to generate alternative envelope shape designs, with integrated energy simulation, to calculate the energy demand of each design. Shape grammars are particularly suitable to encode architectural design systems, given their ability to encode compositional design principles. Their downside is the complexity in developing computer implementations. This methodology converts a grammar into a parametric design system and is illustrated with an application to the grammar for Frank Lloyd Wright's prairie houses.

Abstract First initiatives of energy and climate action at the local level can be tracked back into the 1990s. Nevertheless, only in the last decade integrated local energy planning initiatives have gained greater expression. The new energy paradigm calls for a need to focus on the energy services for which energy is actually demanded and to critically assess the levels of demand and identify the appropriate energy carriers and technologies to satisfy those services. Thus, a holistic perspective to local energy systems is deemed necessary. This paper proposes a decision support methodology for assisting local sustainable energy planning processes, covering the whole energy planning process – from structuring to the choice of the action plan. From the energy model point of view, the focus is on providing an energy services-oriented modelling approach and a technically solid and comprehensive basis for evaluating alternative energy action plans. From the process point of view, since energy planning involves choices regarding the future of the community, the values and preferences of the local actors are included through a multi-criteria evaluation process. The methodology was applied to a practical case in Portugal, demonstrating how it can be made operational.

This paper proposes the use of decomposition analysis to assess the effect of local energy-related actions towards climate change mitigation, and thus improve policy evaluation and planning at the local level. The assessment of the impact of local actions has been a challenge, even from a strictly technical perspective. This happens because the total change observed is the result of multiple factors influencing local energy-related greenhouse gas (GHG) emissions, many of them not even influenced by local authorities. A methodology was developed, based on a recently developed decomposition model, that disaggregates the total observed changes in the local energy system into multiple causes/effects (including local socio-economic evolution, technology evolution, higher-level governance frame and local actions). The proposed methodology, including the quantification of the specific effect associated with local actions, is demonstrated with the case study of the municipality of Malmö (Sweden) in the timeframe between 1990 and 2015.

Abstract Defining objectives is an essential part of planning processes, useful to induce creative alternatives and to derive the attributes (criteria) on which the alternatives will be assessed. This article identifies a set of energy planning (EP) objectives and measurable attributes specifically tailored for promoting sustainability in developing countries. A literature review was conducted as part of a problem structuring activity to identify applicable EP objectives. The Economic Community of West African States (ECOWAS), with an emphasis on Ghana, was used as a representative area of study. Two EP objectives specific to the context of the ECOWAS were identified, namely, ensuring maintainability of the final energy supply system and access to final energy services. These were included within a set of EP objectives which consisted of the additional of increasing primary energy security and reliability of the final energy system, and decreasing costs (investment, operation & maintenance), influence of the energy system on the global climate, impact of the energy system on the local environment. These EP objectives were made operational through the identification of a set of corresponding measurable attributes. This EP objective set, used within a structured EP methodology, may support the implementation and sustainability of national EP activities in the countries of the region.

Interest in the interaction between energy and health within the built environment has been increasing in recent years, in the context of sustainable development. However, in order to promote health and wellbeing across all ages it is necessary to have a better understanding of the association between health and energy at household level. This study contributes to this debate by addressing the case of Portugal using data from the Household Budget Survey (HBS) microdata database. A two-part model is applied to estimate health expenditures based on energy-related expenditures, as well as socioeconomic variables. Additional statistical methods are used to enhance the perception of relevant predictors for health expenditures. Our findings suggest that given the high significance and coefficient value, energy expenditure is a relevant explanatory variable for health expenditures. This result is further validated by a dominance analysis ranking. Moreover, the results show that health gains and medical cost reductions can be a key factor to consider on the assessment of the economic viability of energy efficiency projects in buildings. This is particularly relevant for the older and low-income segments of the population.

Abstract This work developed a methodology and an associated calculation platform in order to identify the economic efficient design solutions for residential Net Zero Energy Building (NZEB) design considering the influence of the local climate, the endogenous energy resources and the local economic conditions. One case study of a detached house for 3 climates was analyzed with the tool developed in order to gain insights on the economic space of NZEB solutions and the influence of the climatic context. A methodology for assisting the choice of economically efficient NZEB solutions from the early design stage is now available. Its use in practice may be of great relevance as the results showed that the differences between an economically efficient and economically inefficient NZEB can be over three times both in terms of initial and life cycle cost.

This paper identifies and characterizes the technical measures and policy instruments that can be used to promote energy efficiency and the use of renewable sources for domestic hot water (DHW). DHW presents a considerable potential for abatement of greenhouse gas emissions around the world. Measures were characterized in terms of level of transformation, impact and scope, among others. Policy instruments were characterized in terms of target groups, competences required for implementation, major challenges and nature of the instruments. A matrix showing the applicability of policy instruments per technical measure was derived, enabling policy makersto better choose articulated measures and policy instruments for their policy packs.

Abstract Local actions are currently seen as of major importance for the achievement of climate change mitigation overall targets. As they become more and more patent, it is essential to know more about the extent of their influence. How much are local actions actually contributing to climate change mitigation? What is the effectiveness, relevance and efficiency of these actions, and what are their effects in terms of energy savings and GHG emissions reduction? The main objective of this work is to review the existing work on the evaluation of climate and energy policies considering the difficulties that come along with the assessment of the effects of local actions. In order to do so, an analytical framework composed by the following features was developed: moment of the evaluation; object; geographical scope; causal links consideration; and merit assessment. Despite the existence of several studies that may contribute to the assessment of local actions, the reviewed approaches do not fully assess the contribution of local actions towards climate change mitigation – either by not decoupling its effects from other ongoing or past policies or by not providing their merit assessment. Nevertheless, the analysis of existing approaches was important to acknowledge the implications of different options, providing some guidelines for the development of an improved evaluation methodology. The review has proven the need for an ex-post approach that focus on the actual effects of local actions (considering potential interactions with other policies and the local context) as well as the importance of a merit assessment based on comprehensive benchmarks.