Marina Mistretta

Decision-making in energy planning. Application of the Electre method at regional level for the diffusion of renewable energy technology

The authors show an application of the multicriteria decision-making methodology used to assess an action plan for the diffusion of renewable energy technologies at regional scale. This methodological tool gives the decision-maker considerable help in the selection of the most suitable innovative technologies in the energy sector, according to preliminary fixed objectives. In this paper, a case study is carried out for the island of Sardinia. This region presents, on one hand, a high potential for energy resources exploitation, but on the other hand, it represents a specific case among other Italian regions, because of its socio-economic status and history.

Resource Consumption and Environmental Impacts of the Agrofood Sector: Life Cycle Assessment of Italian Citrus-Based Products

Food production and consumption cause significant environmental burdens during the product life cycles. As a result of intensive development and the changing social attitudes and behaviors in the last century, the agrofood sector is the highest resource consumer after housing in the EU. This paper is part of an effort to estimate environmental impacts associated with life cycles of the agrofood chain, such as primary energy consumption, water exploitation, and global warming. Life cycle assessment is used to investigate the production of the following citrus-based products in Italy: essential oil, natural juice, and concentrated juice from oranges and lemons. The related process flowcharts, the relevant mass and energy flows, and the key environmental issues are identified for each product. This paper represents one of the first studies on the environmental impacts from cradle to gate for citrus products in order to suggest feasible strategies and actions to improve their environmental performance.

Life cycle assessment of Italian citrus-based products. Sensitivity analysis and improvement scenarios

Though many studies concern the agro-food sector in the EU and Italy, and its environmental impacts, literature is quite lacking in works regarding LCA application on citrus products. This paper represents one of the first studies on the environmental impacts of citrus products in order to suggest feasible strategies and actions to improve their environmental performance. In particular, it is part of a research aimed to estimate environmental burdens associated with the production of the following citrus-based products: essential oil, natural juice and concentrated juice from oranges and lemons. The life cycle assessment of these products, published in a previous paper, had highlighted significant environmental issues in terms of energy consumption, associated CO(2) emissions, and water consumption. Starting from such results the authors carry out an improvement analysis of the assessed production system, whereby sustainable scenarios for saving water and energy are proposed to reduce environmental burdens of the examined production system. In addition, a sensitivity analysis to estimate the effects of the chosen methods will be performed, giving data on the outcome of the study. Uncertainty related to allocation methods, secondary data sources, and initial assumptions on cultivation, transport modes, and waste management is analysed. The results of the performed analyses allow stating that every assessed eco-profile is differently influenced by the uncertainty study. Different assumptions on initial data and methods showed very sensible variations in the energy and environmental performances of the final products. Besides, the results show energy and environmental benefits that clearly state the improvement of the products eco-profile, by reusing purified water use for irrigation, using the railway mode for the delivery of final products, when possible, and adopting efficient technologies, as the mechanical vapour recompression, in the pasteurisation and concentration of juice.

Managing municipal solid waste

GoalThis research aims to assess the environmental effects of integrated strategies in a municipal waste management system. In particular, analysis is focused on a waste stream in Palermo, where landfill involves the prompt disposal of the most waste after collection. The current local management system is compared with two integrated waste management alternatives. Both the options comply with Italian regulations, but each one predicts adopting the available technologies in different ways.Methods and objectivesEnergetic and environmental balances are carried out in each management system referring to local waste composition in order to quantify energy consumption, the recovery of material and energy, and the environmental releases. Impact assessment is carried out to define the environmental profile of each option. Impact categories are defined and inventory data, by means of a suitable aggregation, can be used to evaluate the potential contribution that system inputs and outputs could bring to the relative category.ResultsIn opposition to the current management, which involves energy balance at a loss, the mass and energy balances outcomes in both of the two hypothetical management systems show the capability to obtain energy and material recovery to a substantial extent. Sorted collection plays a remarkable role in the improvement of environmental performance of management systems. In particular, the thermal treatment of waste associated with energy recovery, and the concomitant material recycling, increase the saving of energy.ConclusionsEnvironmental pressure factors of the management system are assessed depending on the relevant consumption of raw materials and energy, and on the emission of pollutants. The resulting figures reflect the two different integrated management options as being sustainable solutions for achieving an improvement in environmental performance, which is based on increasing the value of waste, as an alternative to resources, and the reduction of environmental releases. Life Cycle Assessment of municipal waste management systems can be usefully applied to define synthetic indices of environmental impact. These indices could single out possible alternatives in multi-criteria analysis, together with economic and technical parameters.

Nearly Zero Energy Building Refurbishment

The recast of the Energy Performance of Buildings Directive (EPBD) was adopted by the European Parliament and the Council of the European Union on 19 May 2010. For new buildings, the recast fixes 2 ...

New exergy criterion in the “multi-criteria” context: a life cycle assessment of two plaster products

This paper deals with the exergy analysis (EXA) of plaster materials and ranks the environmental burdens due to the production of such materials. The calculation of the exergy loss during the whole examined process represents a relevant index, looking at the technology improvement of a process, as a suitable tool in aid of the trade-off of alternative materials in the decision making. A life cycle inventory is performed for building plaster products and the matrix method is used. The authors extend the application of EXA to life cycle assessment, conducting an exergetic life cycle assessment, and propose an exergetic index in the framework of multi-criteria decision making. An exergy balance, accounting for energy and material flows, is applied to calculate the exergy losses and efficiencies for each stage of the examined processes: resources extraction, materials processing, transport and product manufacturing. Furthermore, exergy values are calculated for the pollutants and wastes.

Life Cycle Assessment in the Olive Oil Sector

The olive oil industry is a significant productive sector in the European Union and the related production process is characterised by a variety of different practices and techniques for the agricultural production of olives and for their processing into olive oil. Depending on these different procedures, olive oil production is associated with several adverse effects on the environment, both in the agricultural and in the olive oil production phase. As a consequence, tools such as LCA are becoming increasingly important for this type of industry. Following an overview of the characteristics of the olive oil supply chain and its main environmental problems, the authors of this chapter provide a description of the international state of the art of LCA implementation in this specific sector, as well as briefly describing other life cycle thinking methodologies and tools (such as simplified LCA, footprint labels and Environmental Product Declarations). Then, the methodological problems connected with the application of LCA in the olive oil production sector are analysed in depth, starting from a critical comparative analysis of the applicative LCA case studies in the olive oil production supply chain. Finally, guidelines for the application of LCA in the olive oil production sector are proposed.

Energy planning methodology of net-zero energy solar neighborhoods in the Mediterranean basin

The article proposes a simplified methodology to optimize solar energy gains at district level in the Mediterranean area toward the achievement of the net-zero energy district target, to be applicable as well in similar hot climates. The approach includes a wide use of parametric analysis to explore the most impactful aspects of the design of solar net-zero energy districts: single unit shape, building mutual distances, road shape, building orientation, photovoltaics area availability to identify the optimal design solution. Thirty-two different district configurations are explored: results show that in the Mediterranean context, it is possible to reach the net-zero energy district target in several configurations investigated; however, cooling energy requirements can vary up to 20% in the different combinations examined. In a context of high demographic growth and consequently of expected rise of housing demand especially on the southern side of the Mediterranean, the proposed method can be useful in the application of bioclimatic concepts to large scale energy planning and energy policies as well for practitioners and building designers.

The Use of Genetic Algorithms to Solve the Allocation Problems in the Life Cycle Inventory

One of the most controversial issues in the development of Life Cycle Inventory (LCI) is the allocation procedure, which consists in the partition and distribution of economic flows and environmental burdens among to each of the products of a multi-output system. Because of the use of the allocation represents a source of uncertainty in the LCI results, the authors present a new approach based on genetic algorithms (GAs) to solve the multi-output systems characterized by a rectangular matrix of technological coefficients, without using computational methods such as the allocation procedure. In this Chapter, the GAs’ approach is applied to an ancillary case study related to a cogeneration process. In detail, the authors hypothesized that there are the following multi-output processes in the case study: (1) cogeneration of electricity and heat; (2) co-production of diesel and light fuel oil; (3) co-production of copper and recycled copper. The energy and mass balances are respected by means of specific bonds that limit the space in which the GA searches the solution. The results show low differences between the inventory vector derived from the GA application and that one obtained applying the substitution method and the allocation procedure based on the energy content of the outputs. To avoid the allocation, the application of GA to calculate the LCI seems to be a promising method.

Benefits of Refurbishment

Energy and environmental performances of buildings strictly depend on many factors related to the choice of construction materials, HVAC plants and equipment, design, installation and use. By definition, a building interacts closely with its environment. The interactions between building and climate, plants and users have to be taken into account. This aspect is evident in new buildings design process, but it is even more important in the design phase of an existing building renovation, during which actions of energy saving are developed. This chapter summarises the results of the energy and environmental assessment of a set of retrofit actions implemented in the framework of the EU Project ‘BRITA in PuBs’. The main goals were to improve building energy and environmental performances following a life-cycle approach and to support the project partners to select the retrofit actions involving the highest energy saving and the lowest environmental impacts. Synthetic indices, as energy and GWP payback times, and energy return ratio, are defined to better describe the energy and environmental performances of the actions. The use of the life-cycle approach was very successful and potentially transferable to other contexts of building retrofit study.