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Special Issue "16th CIRIAF National Congress – Sustainable Development, Environment and Human Health Protection"

A special issue of Energies (ISSN 1996-1073).

Deadline for manuscript submissions: closed (31 October 2016)

Special Issue Editor

Guest Editor
Prof. Dr. Francesco Asdrubali

Department of Engineering, Roma Tre University, Via Vito Volterra, 62, 00146 Roma, Italy
E-Mail
Phone: 06-57336487 mobile: 329-4103927

Special Issue Information

Dear Colleagues,

CIRIAF (Inter-University Research Center on Pollution and Environment “Mauro Felli)” is a research center, based at the University of Perugia, which promotes interdisciplinary research activities in the fields of environmental pollution and its health and socio-economic effects, sustainable development, renewable and alternative energy, energy planning, sustainable mobility. 100 professors from 14 different Italian universities are involved in the activities of the centre.

The CIRIAF National Congress, at its sixteen edition in 2016, has become, over time, an important event for researchers and experts (engineers, physicists, chemists, architects, doctors, economists) coming not only from the academic world, but also from Ministries, Environmental Agencies and local Authorities. The annual meeting in Perugia is an opportunity to discuss the issues related to Energy, Environment and Sustainable Development.

The 16th Congress, which took place in Assisi (Perugia) in the days 7-9-April 2016, was quite successful. 93 papers were presented during the Congress, divided into the following  Sessions in line with the congress tradition and in the meantime of great interest:

  • Environmental Footprint

  • Sustainable and Green Buildings

  • Environmental and Socio-Economic Sustainability

  • Renewable and Alternative Energies and Plants

  • Green Chemistry

  • Climate change and impact on natural and agricultural ecosystems

  • Environmental Pollution and Human Health

A Special Session was also dedicated to Thermal Energy Storage, within the EU H2020 funded Project “INPATH-TES – PhD on Innovation Pathways for Thermal Energy Storage” with various international contributions.

As usual, the ceremony of the “Mauro Felli” award took place during the Congress. The award, established to honor the memory of the founder and first Director of CIRIAF, is intended for young graduates, Ph.D. students or researchers who have carried out research activities in the fields of pollution from physical agents, effects of environmental pollution on humans or related issues.

Thanks to the agreement with the international publishing house MDPI, I am happy to introduce you the Special issue of ENERGIES containing the best energy-related papers presented at the Congress. Another Special issue of SUSTAINABILITY (MDPI) will contain the best papers dealing with environmental and sustainable development issues.

The Special Issue will include the best papers presented at the Congress, selected by the Scientific Committee with the help of the various Chairmen of the Sessions.

Prof. Francesco Asdrubali
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1000 CHF (Swiss Francs).

Published Papers (17 papers)

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Research

Open AccessArticle Thermal and Stability Investigation of Phase Change Material Dispersions for Thermal Energy Storage by T-History and Optical Methods
Energies 2017, 10(3), 354; doi:10.3390/en10030354
Received: 29 September 2016 / Revised: 22 February 2017 / Accepted: 2 March 2017 / Published: 13 March 2017
Cited by 1 | PDF Full-text (7310 KB) | HTML Full-text | XML Full-text
Abstract
Glauber’s salt (sodium sulphate decahydrate) is a promising phase change material (PCM) for use in the building sector, thanks to its high enthalpy of fusion associated with a proper phase transition temperature. It also offers economic and environmental advantages because it can be
[...] Read more.
Glauber’s salt (sodium sulphate decahydrate) is a promising phase change material (PCM) for use in the building sector, thanks to its high enthalpy of fusion associated with a proper phase transition temperature. It also offers economic and environmental advantages because it can be obtained as a byproduct from the disposal process of lead batteries. However, due to phenomena of phase segregation and supercooling, Glauber’s salt cannot be used in its pure state and requires the addition of rheological modifiers and nucleating agents. In this work, the initial thermal performances of mixtures based on Glauber’s salt with different compositions are compared by using the T-history method and adopting sonication for mixing, and following the same preparation procedure for all the samples. With fixed composition, the effects of the addition sequence of the reagents are also examined. The analysis carried out by optical methods based on light scattering (Turbiscan equipment) allowed us to identify the kinetics of destabilization for each sample and revealed the need to specify in detail the preparation stages of PCMs, in order to make the composition reproducible in the laboratory and on a wider scale. Full article
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Open AccessArticle Energy Contribution of OFMSW (Organic Fraction of Municipal Solid Waste) to Energy-Environmental Sustainability in Urban Areas at Small Scale
Energies 2017, 10(2), 229; doi:10.3390/en10020229
Received: 19 October 2016 / Revised: 3 February 2017 / Accepted: 9 February 2017 / Published: 15 February 2017
Cited by 9 | PDF Full-text (2944 KB) | HTML Full-text | XML Full-text
Abstract
Urban waste management is one of the most challenging issues in energy planning of medium and large cities. In addition to the traditional landfill method, many studies are investigating energy harvesting from waste, not as a panacea but as a foreseeable solution. Thermo-chemical
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Urban waste management is one of the most challenging issues in energy planning of medium and large cities. In addition to the traditional landfill method, many studies are investigating energy harvesting from waste, not as a panacea but as a foreseeable solution. Thermo-chemical conversion to biogas, or even bio-methane under certain conditions, could be an option to address this challenge. This study focuses on municipal solid waste conversion to biogas as a local energy supply for the cities. Three urban models and their subdivision into urban areas were identified along with a typical Organic Fraction of Municipal Solid Waste (OFMSW) matrix for each urban area. Then, an energy analysis was carried out to provide an optimization map for an informed choice by urban policy-makers and stakeholders. The results highlighted how the urban context and its use could affect the opportunity to produce energy from waste or to convert it in fuel. So, in this case, sustainability means waste turning from a problem to a renewable resource. Full article
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Open AccessArticle Cold Storage for a Single-Family House in Italy
Energies 2016, 9(12), 1043; doi:10.3390/en9121043
Received: 13 September 2016 / Revised: 14 November 2016 / Accepted: 6 December 2016 / Published: 12 December 2016
Cited by 1 | PDF Full-text (4037 KB) | HTML Full-text | XML Full-text
Abstract
This work deals with the operation, modeling, simulation, and cost evaluation of two different cold storage systems for a single-family house in Italy, that differ from one another on the cold storage material. The two materials used to perform the numerical simulations of
[...] Read more.
This work deals with the operation, modeling, simulation, and cost evaluation of two different cold storage systems for a single-family house in Italy, that differ from one another on the cold storage material. The two materials used to perform the numerical simulations of the cold storage systems are represented by cold water and a phase change material (PCM), and the numerical simulations have been realized by means of numerical codes written in Matlab environment. The main finding of the present work is represented by the fact that, for the considered user characteristics, and under the Italian electricity tariff policy, the use of a proper designed cold storage system characterized by an effective operation strategy could represent a viable solution from an economical point of view. Full article
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Open AccessArticle Assessment of Renewable Sources for the Energy Consumption in Malta in the Mediterranean Sea
Energies 2016, 9(12), 1034; doi:10.3390/en9121034
Received: 24 September 2016 / Revised: 18 November 2016 / Accepted: 28 November 2016 / Published: 8 December 2016
Cited by 11 | PDF Full-text (7696 KB) | HTML Full-text | XML Full-text
Abstract
The main purpose of this paper is to analyze the energy production in the Maltese islands, focusing on the employment of renewable energies in order to increase their energy independence. The main renewable source here proposed is wave energy: thanks to a strategic
[...] Read more.
The main purpose of this paper is to analyze the energy production in the Maltese islands, focusing on the employment of renewable energies in order to increase their energy independence. The main renewable source here proposed is wave energy: thanks to a strategic position, Malta will be able to produce electrical energy using an innovative type of Wave Energy Converter (WEC) based on the prototype of a linear generator realized by University of Palermo. The use of this new technology will be able to cut down the electrical energy production from traditional power plants and, consequently, the greenhouse gas emissions (GHG). Wave energy source and off-shore photovoltaic (PV) technology are here proposed. Particularly, the installation of 12 wave farms, for a total installed capacity of 86 MW, will generate about 9.5% of Malta’s energy requirement in 2025, while the installation of 9.6 MW of off-shore PV will generate about 0.73%. Full article
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Open AccessArticle The Desalination Process Driven by Wave Energy: A Challenge for the Future
Energies 2016, 9(12), 1032; doi:10.3390/en9121032
Received: 24 September 2016 / Revised: 13 November 2016 / Accepted: 25 November 2016 / Published: 7 December 2016
Cited by 10 | PDF Full-text (4544 KB) | HTML Full-text | XML Full-text
Abstract
The correlation between water and energy is currently the focus of several investigations. In particular, desalination is a technological process characterized by high energy consumption; nevertheless, desalination represents the only practicable solution in several areas, where the availability of fresh water is limited
[...] Read more.
The correlation between water and energy is currently the focus of several investigations. In particular, desalination is a technological process characterized by high energy consumption; nevertheless, desalination represents the only practicable solution in several areas, where the availability of fresh water is limited but brackish water or seawater are present. These natural resources (energy and water) are essential for each other; energy system conversion needs water, and electrical energy is necessary for water treatment or transport. Several interesting aspects include the study of saline desalination as an answer to freshwater needs and the application of renewable energy (RE) devices to satisfy electrical energy requirement for the desalination process. A merge between renewable energy and desalination is beneficial in that it is a sustainable and challenging option for the future. This work investigates the possibility of using renewable energy sources to supply the desalination process. In particular, as a case study, we analyze the application of wave energy sources in the Sicilian context. Full article
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Open AccessArticle A Procedure to Perform Multi-Objective Optimization for Sustainable Design of Buildings
Energies 2016, 9(11), 915; doi:10.3390/en9110915
Received: 14 September 2016 / Revised: 27 October 2016 / Accepted: 31 October 2016 / Published: 4 November 2016
Cited by 2 | PDF Full-text (7984 KB) | HTML Full-text | XML Full-text
Abstract
When dealing with sustainable design concepts in new construction or in retrofitting existing buildings, it is useful to define both economic and environmental performance indicators, in order to select the optimal technical solutions. In most of the cases, the definition of the optimal
[...] Read more.
When dealing with sustainable design concepts in new construction or in retrofitting existing buildings, it is useful to define both economic and environmental performance indicators, in order to select the optimal technical solutions. In most of the cases, the definition of the optimal strategy is not trivial because it is necessary to solve a multi-objective problem with a high number of the variables subjected to nonlinear constraints. In this study, a powerful multi-objective optimization genetic algorithm, NSGAII (Non-dominated Sorting Genetic Algorithm-II), is used to derive the Pareto optimal solutions, which can illustrate the whole trade-off relationship between objectives. A method is then proposed, to introduce uncertainty evaluation in the optimization procedure. A new university building is taken as a case study to demonstrate how each step of the optimization process should be performed. The results achieved turn out to be reliable and show the suitableness of this procedure to define both economic and environmental performance indicators. Similar analysis on a set of buildings representatives of a specific region might be used to assist local/national administrations in the definition of appropriate legal limits that will permit a strategic optimized extension of renewable energy production. Finally, the proposed approach could be applied to similar optimization models for the optimal planning of sustainable buildings, in order to define the best solutions among non-optimal ones. Full article
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Open AccessArticle Thermal Analysis of an Industrial Furnace
Energies 2016, 9(10), 833; doi:10.3390/en9100833
Received: 17 May 2016 / Revised: 2 September 2016 / Accepted: 10 October 2016 / Published: 18 October 2016
Cited by 2 | PDF Full-text (5950 KB) | HTML Full-text | XML Full-text
Abstract
Industries, which are mainly responsible for high energy consumption, need to invest in research projects in order to develop new managing systems for rational energy use, and to tackle the devastating effects of climate change caused by human behavior. The study described in
[...] Read more.
Industries, which are mainly responsible for high energy consumption, need to invest in research projects in order to develop new managing systems for rational energy use, and to tackle the devastating effects of climate change caused by human behavior. The study described in this paper concerns the forging industry, where the production processes generally start with the heating of steel in furnaces, and continue with other processes, such as heat treatments and different forms of machining. One of the most critical operations, in terms of energy loss, is the opening of the furnace doors for insertion and extraction operations. During this time, the temperature of the furnaces decreases by hundreds of degrees in a few minutes. Because the dispersed heat needs to be supplied again through the combustion of fuel, increasing the consumption of energy and the pollutant emissions, the evaluation of the amount of lost energy is crucial for the development of systems which can contain this loss. To perform this study, CFD simulation software was used. Results show that when the door opens, because of temperature and pressure differences between the furnace and the ambient air, turbulence is created. Results also show that the amount of energy lost for an opening of 10 min for radiation, convection and conduction is equal to 5606 MJ where convection is the main contributor, with 5020 MJ. The model created, after being validated, has been applied to perform other simulations, in order to improve the energy performance of the furnace. Results show that reducing the opening time of the door saves energy and limits pollutant emissions. Full article
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Open AccessArticle Application of Absorption Systems Powered by Solar Ponds in Warm Climates for the Air Conditioning in Residential Buildings
Energies 2016, 9(10), 821; doi:10.3390/en9100821
Received: 30 May 2016 / Revised: 23 September 2016 / Accepted: 28 September 2016 / Published: 14 October 2016
Cited by 3 | PDF Full-text (4400 KB) | HTML Full-text | XML Full-text
Abstract
The increasing importance of a significant reduction of CO2 emissions in the atmosphere asks the scientific community to find other solutions than fossil fuels with respect to the air conditioning of indoor environments. Nowadays, a priority is represented by the energy expenses
[...] Read more.
The increasing importance of a significant reduction of CO2 emissions in the atmosphere asks the scientific community to find other solutions than fossil fuels with respect to the air conditioning of indoor environments. Nowadays, a priority is represented by the energy expenses reduction, in which residential buildings report one of the highest energy consumption levels among developed countries. The application of alternative energies in residential buildings is an issue debated in the European Commission for the reduction of greenhouse gas emissions with the objective to obtain 20% of the demand from renewable sources. This paper suggests the application of the solar energy stored in solar ponds to air-condition small residential buildings, through the use of absorption machines. A feasibility analysis was carried out in some places characterized by climates that are suitable to make the solution here suggested sustainable from an energetic point of view. Buildings characterized by different boundary surface/volume ratios were examined and the energy saving, the amount of CO2 that was not emitted in the environment and the return of investments with respect to a more traditional solution were evaluated. Full article
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Open AccessArticle Combined Production and Conversion of Energy in an Urban Integrated System
Energies 2016, 9(10), 817; doi:10.3390/en9100817
Received: 21 June 2016 / Revised: 5 September 2016 / Accepted: 29 September 2016 / Published: 13 October 2016
Cited by 4 | PDF Full-text (4145 KB) | HTML Full-text | XML Full-text
Abstract
Within the framework of the European Combined Efficient Large Scale Integrated Urban Systems (CELSIUS) project, the Genoa demonstrator involves the insertion of a turbo expander (TE) to substitute the standard throttling process in a natural gas expansion station. In this way, the currently
[...] Read more.
Within the framework of the European Combined Efficient Large Scale Integrated Urban Systems (CELSIUS) project, the Genoa demonstrator involves the insertion of a turbo expander (TE) to substitute the standard throttling process in a natural gas expansion station. In this way, the currently wasted mechanical energy will be recovered, while an internal combustion combined heat and power (CHP) unit will be used to meet the heating requirements of the gas before the expansion and to serve a small district heating network (DHN). Both TE and CHP are capable of delivering electric power (EP) up to 1 MW. In order to match the EP production vs demand is highly desirable to use the EP extra capacity for local EP final users, such as a nearby public school and a gas refueling station (RS). For limiting the school’s consumption of fossil fuel, it is possible to use the EP surplus generated by the demonstrator to feed a heat pump in parallel to the heating conventional system. With regard to the RS, the compressors are currently driven by electric motors, with a high-energy consumption. The integrated system gives the possibility of exploiting the surplus of electricity production and of recovering heat, which would be otherwise wasted, from the intercooling of compressed gas, thus powering the DHN through a preheating system. The result expected from this strategy is a relevant energy and emissions saving due to an integrated use of the electricity generated by the Genoese demonstrator for feeding the nearby school and RS. Full article
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Open AccessArticle Experimental and Numerical Research Activity on a Packed Bed TES System
Energies 2016, 9(9), 758; doi:10.3390/en9090758
Received: 11 July 2016 / Revised: 6 September 2016 / Accepted: 8 September 2016 / Published: 20 September 2016
Cited by 2 | PDF Full-text (2803 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents the results of experimental and numerical research activities on a packed bed sensible thermal energy storage (TES) system. The TES consists of a cylindrical steel tank filled with small alumina beads and crossed by air used as the heat transfer
[...] Read more.
This paper presents the results of experimental and numerical research activities on a packed bed sensible thermal energy storage (TES) system. The TES consists of a cylindrical steel tank filled with small alumina beads and crossed by air used as the heat transfer fluid. Experimental tests were carried out while varying some operating parameters such as the mass flow rate, the inlet–outlet temperature thresholds and the aspect ratio (length over diameter). Numerical simulations were carried out using a one-dimensional model, specifically developed in the Matlab-Simulink environment and a 2D axisymmetric model based on the ANSYS-Fluent platform. Both models are based on a two-equation transient approach to calculate fluid and solid phase temperatures. Thermodynamic properties were considered to be temperature-dependent and, in the Computational Fluid Dynamics (CFD) model, variable porosity of the bed in the radial direction, thermal losses and the effective conductivity of the alumina beads were also considered. The simulation results of both models were compared to the experimental ones, showing good agreement. The one-dimensional model has the advantage of predicting the axial temperature distribution with a very low computational cost, but it does not allow calculation of the correct energy stored when the temperature distribution is strongly influenced by the wall. To overcome this problem a 2D CFD model was used in this work. Full article
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Open AccessArticle Energy Opportunities from Lignocellulosic Biomass for a Biorefinery Case Study
Energies 2016, 9(9), 748; doi:10.3390/en9090748
Received: 29 July 2016 / Revised: 5 September 2016 / Accepted: 7 September 2016 / Published: 14 September 2016
Cited by 2 | PDF Full-text (986 KB) | HTML Full-text | XML Full-text
Abstract
This work presents some energy considerations concerning a biorefinery case study that has been carried out by the CRB/CIRIAF of the University of Perugia. The biorefinery is the case study of the BIT3G project, a national funded research project, and it uses the
[...] Read more.
This work presents some energy considerations concerning a biorefinery case study that has been carried out by the CRB/CIRIAF of the University of Perugia. The biorefinery is the case study of the BIT3G project, a national funded research project, and it uses the lignocellulosic biomass that is available in the territory as input materials for biochemical purposes, such as cardoon and carthamus. The whole plant is composed of several sections: the cardoon and carthamus seed milling, the oil refinement facilities, and the production section of some high quality biochemicals, i.e., bio-oils and fatty acids. The main goal of the research is to demonstrate energy autonomy of the latter section of the biorefinery, while only recovering energy from the residues resulting from the collection of the biomass. To this aim, this work presents the quantification of the energy requirements to be supplied to the considered biorefinery section, the mass flow, and the energy and chemical characterization of the biomass. Afterwards, some sustainability strategies have been qualitatively investigated in order to identify the best one to be used in this case study; the combined heat and power (CHP) technology. Two scenarios have been defined and presented: the first with 6 MWt thermal input and 1.2 MWe electrical power as an output and the second with 9 MWt thermal input and 1.8 MWe electrical power as an output. The first scenario showed that 11,000 tons of residual biomass could ensure the annual production of about 34,000 MWht, equal to about the 72% of the requirements, and about 9600 MWhe, equal to approximately 60% of the electricity demand. The second scenario showed that 18,000 tons of the residual biomass could ensure the total annual production of about 56,000 MWht, corresponding to more than 100% of the requirements, and about 14,400 MWhe, equal to approximately 90% of the electricity demand. In addition, the CO2 emissions from the energy valorization section have been quantified and the possibility of re-using the CO2 flow in order to produce methane is described. Full article
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Open AccessArticle Influence of Insulating Materials on Green Building Rating System Results
Energies 2016, 9(9), 712; doi:10.3390/en9090712
Received: 13 June 2016 / Revised: 28 July 2016 / Accepted: 4 August 2016 / Published: 5 September 2016
Cited by 6 | PDF Full-text (5290 KB) | HTML Full-text | XML Full-text
Abstract
This paper analyzes the impact of a change in the thermal insulating material on both the energy and environmental performance of a building, evaluated through two different green building assessment methods: Leadership in Energy and Environmental Design (LEED) and Istituto per l’innovazione e
[...] Read more.
This paper analyzes the impact of a change in the thermal insulating material on both the energy and environmental performance of a building, evaluated through two different green building assessment methods: Leadership in Energy and Environmental Design (LEED) and Istituto per l’innovazione e Trasparenza degli Appalti e la Compatibilità Ambientale (ITACA). LEED is one of the most qualified rating systems at an international level; it assesses building sustainability thanks to a point-based system where credits are divided into six different categories. One of these is fully related to building materials. The ITACA procedure derives from the international evaluation system Sustainable Building Tool (SBTool), modified according to the Italian context. In the region of Umbria, ITACA certification is composed of 20 technical sheets, which are classified into five macro-areas. The analysis was developed on a residential building located in the central Italy. It was built taking into account the principles of sustainability as far as both structural and technical solutions are concerned. In order to evaluate the influence of thermal insulating material, different configurations of the envelope were considered, replacing the original material (glass wool) with a synthetic one (expanded polystyrene, EPS) and two natural materials (wood fiber and kenaf). The study aims to highlight how the materials characteristics can affect building energy and environmental performance and to point out the different approaches of the analyzed protocols. Full article
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Open AccessArticle Modeling and Optimization of the Thermal Performance of a Wood-Cement Block in a Low-Energy House Construction
Energies 2016, 9(9), 677; doi:10.3390/en9090677
Received: 19 May 2016 / Revised: 12 August 2016 / Accepted: 14 August 2016 / Published: 24 August 2016
PDF Full-text (6282 KB) | HTML Full-text | XML Full-text
Abstract
The reduction of building energy consumption requires appropriate planning and design of the building’s envelope. In the last years, new innovative materials and construction technologies used in new or refurbished buildings have been developed in order to achieve this objective, which are also
[...] Read more.
The reduction of building energy consumption requires appropriate planning and design of the building’s envelope. In the last years, new innovative materials and construction technologies used in new or refurbished buildings have been developed in order to achieve this objective, which are also needed for reducing greenhouse gases emissions and building maintenance costs. In this work, the thermal conductance of a brick, made of wood and cement, used in a low-rise building, was investigated with a heat flow meter (HFM) and with numerical simulation using the Ansys® software package (Canonsburg, PA, USA). Due to their influence on the buildings’ thermal efficiency, it is important to choose an appropriate design for the building blocks. Results obtained by the finite element modeling of the construction material and by in-situ analysis conducted on a real building are compared, and furthermore a thermal optimization of the shape of the material is suggested. Full article
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Open AccessArticle Energy Management of an Off-Grid Hybrid Power Plant with Multiple Energy Storage Systems
Energies 2016, 9(8), 661; doi:10.3390/en9080661
Received: 1 June 2016 / Revised: 3 August 2016 / Accepted: 4 August 2016 / Published: 19 August 2016
Cited by 2 | PDF Full-text (4038 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, an off-grid hybrid power plant with multiple storage systems for an artificial island is designed and two possible strategies for the management of the stored energy are proposed. Renewable power sources (wind/solar technologies) are used as primary power suppliers. A
[...] Read more.
In this paper, an off-grid hybrid power plant with multiple storage systems for an artificial island is designed and two possible strategies for the management of the stored energy are proposed. Renewable power sources (wind/solar technologies) are used as primary power suppliers. A lead-acid battery pack (BAT) and a reversible polymer electrolyte fuel cell are employed to fulfill the power demand and to absorb extra power. The reversible fuel cell allows reducing costs and occupied space and the fuel cell can be fed by the pure hydrogen produced by means of its reversible operation as an electrolyzer. A diesel engine is employed as backup system. While HOMER Pro® has been employed for a full-factorial-based optimization of the sizes of the renewable sources and the BAT, Matlab/Simulink® has been later used for simulating the plant operation and compare two possible power management control strategies. For the reversible fuel cell sizing, a sensitivity analysis has been carried out varying stack and hydrogen tank sizes. The final choice for plant configuration and power management control strategy has been made on the basis of a comparative analysis of the results, aimed at minimizing fossil fuel consumption and CO2 emissions, battery aging rate and at maximizing the power plant overall efficiency. The obtained results demonstrate the possibility of realizing a renewable power plant, able to match the needs of electrical power in a remote area, by achieving a good integration of different energy sources and facing the intermittent nature of renewable power sources, with very low use of fossil fuels. Full article
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Open AccessArticle Lignocellulosic Ethanol Production from the Recovery of Stranded Driftwood Residues
Energies 2016, 9(8), 634; doi:10.3390/en9080634
Received: 20 June 2016 / Revised: 4 August 2016 / Accepted: 9 August 2016 / Published: 12 August 2016
Cited by 2 | PDF Full-text (697 KB) | HTML Full-text | XML Full-text
Abstract
This paper builds upon a research project funded by the Italian Ministry of Environment, and aims to recover stranded driftwood residues (SDRs), in order to transform a potential pollution and safety issue into valuable bio-resources. In particular, one of the experiments consisted of
[...] Read more.
This paper builds upon a research project funded by the Italian Ministry of Environment, and aims to recover stranded driftwood residues (SDRs), in order to transform a potential pollution and safety issue into valuable bio-resources. In particular, one of the experiments consisted of bioethanol production from lignocellulosic residues. The SDRs were gathered from the Italian coast (Abruzzo Region, Italy) after an intense storm. The biomass recalcitrance, due to its lignocellulosic structure, was reduced by a steam explosion (SE) pretreatment process. Four different pretreatment severity factors (R0) were tested (LogR0 3.65, 4.05, 4.24 and 4.64) in order to evaluate the pretreated material’s accessibility to enzymatic attack and the holocellulose (cellulose plus hemicellulose) recovery. A first enzymatic hydrolysis was performed on the pretreated materials by employing a solid/liquid (S/L) ratio of 1% (w/w) and an enzyme dosage of 30% (w enzyme/w cellulose), in order to estimate the maximum enzymatically accessible cellulose content. Since the primary goal of pretreatment and hydrolysis is to convert as much cellulose as possible into monomeric glucose and recover all the holocellulose, the two pretreated materials showing these features were selected for bioethanol production process. The pretreated materials underwent a semi-simultaneous saccharification and fermentation (SSSF). The SSSF process was performed into two lab-scale bioreactors (5 L) with an S/L ratio of 15% and an enzyme dosage of 15% for five days. The efficiency of the whole bioethanol production process was assessed as ethanol overall yields (g ethanol/100 g raw material). The best overall yield was achieved by sample BS04 (8.98 g ethanol/100 g raw material). Full article
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Open AccessArticle Sustainable New Brick and Thermo-Acoustic Insulation Panel from Mineralization of Stranded Driftwood Residues
Energies 2016, 9(8), 619; doi:10.3390/en9080619
Received: 22 June 2016 / Revised: 25 July 2016 / Accepted: 27 July 2016 / Published: 4 August 2016
PDF Full-text (8498 KB) | HTML Full-text | XML Full-text
Abstract
There is considerable interest recently in by-products for application in green buildings. These materials are widely used as building envelope insulators or blocks. In this study, an experimental study was conducted to test stranded driftwood residues as raw material for possible thermo-acoustic insulation
[...] Read more.
There is considerable interest recently in by-products for application in green buildings. These materials are widely used as building envelope insulators or blocks. In this study, an experimental study was conducted to test stranded driftwood residues as raw material for possible thermo-acoustic insulation panel and environmentally sustainable brick. The thermal and acoustic characteristics of such a natural by-product were examined. Part of samples were mineralized by means of cement-based additive to reinforce the material and enhance its durability as well as fire resistance. Several mixtures with different sizes of ground wood chips and different quantities of cement were investigated. The thermo-acoustic in-lab characterization was aimed at investigating the thermal conductivity, thermal diffusivity, volumetric specific heat, and acoustic transmission loss. All samples were tested before and after mineralization. Results from this study indicate that it is possible to use stranded driftwood residues as building materials with competitive thermo-acoustic properties. In fact, the thermal conductivity was shown to be always around 0.07 W/mK in the unbound samples, and around double that value for the mineralized samples, which present a much higher volumetric specific heat (1.6 MJ/m3K) and transmission loss capability. The lignin powder showed a sort of intermediate behavior between the unbound and the mineralized samples. Full article
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Open AccessArticle Thermal Perception in the Mediterranean Area: Comparing the Mediterranean Outdoor Comfort Index (MOCI) to Other Outdoor Thermal Comfort Indices
Energies 2016, 9(7), 550; doi:10.3390/en9070550
Received: 30 May 2016 / Revised: 7 July 2016 / Accepted: 8 July 2016 / Published: 15 July 2016
Cited by 8 | PDF Full-text (4189 KB) | HTML Full-text | XML Full-text
Abstract
Outdoor thermal comfort is an essential factor of people’s everyday life and deeply affects the habitability of outdoor spaces. However the indices used for its evaluation were usually developed for indoor environments assuming still air conditions and absence of solar radiation and were
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Outdoor thermal comfort is an essential factor of people’s everyday life and deeply affects the habitability of outdoor spaces. However the indices used for its evaluation were usually developed for indoor environments assuming still air conditions and absence of solar radiation and were only later adapted to outdoor spaces. For this reason, in a previous study the Mediterranean Outdoor Comfort Index (MOCI) was developed, which is an empirical index able to estimate the thermal perception of people living in the Mediterranean area. In this study it was compared numerically (by using the data obtained through a field survey) with other selected thermal indices. This comparison, performed in terms of Spearman’s rho correlation coefficient, association Gamma, percentage of correct predictions and cross-tabulation analysis, led to identify the MOCI as the most suitable index to examine outdoor thermal comfort in the interested area. As a matter of fact it showed a total percentage of correct predictions of 35.5%. Good performances were reported even in thermophysiological indices as the Physiological Equivalent Temperature (PET) and Predicted Mean Vote (PMV). Moreover it was revealed that adaptation and acclimatization phenomena tend to have a certain influence as well. Full article

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