An inertial system for the production of electricity and hydrogen from sea wave energy

This paper aims at describing a small scale prototype of a complete wave energy converter system for hydrogen production promoting the opportunity of installation in Sicily, in the Mediterranean Sea. The opportunity to produce hydrogen from sea-water identifies ocean wave energy as the most promising solution for electricity generation including hydrogen production and storage. Even if hydrogen is considered one of the most promising secondary sources, criticism arises from both the academic and the industrial world mainly because hydrogen production requires electricity consumption. Furthermore, safety problems concerning hydrogen storage and transport are actually the main hindrance to fu…

Evaluation of the wave energy density on the Sicilian coast

In this article the wave energy density of the northern Sicilian coasts is evaluated and is used to evaluate the producibility of a wave nergy converter to be installed in an area in the north west part of Sicily. In particular, the objective of the study is the evaluation of a potential installation in an area between Trapani and Palermo, which are the largest cities in the north west part of Sicily. In particular in this research, the wave energy density of Sicily has been analyzed by using an analysis of wave data carried out in a 10-year period, using the measurements of buoyant of National Wave measuring System (RON - Rete Ondametrica Nazionale). The analysis shows that the north-weste…

An Experimental Comparison between an Ironless and a Traditional Permanent Magnet Linear Generator for Wave Energy Conversion

Permanent Magnet Linear Generators (PMLGs) are currently being studied for sea wave energy harvesting. Typically, a PMLG consists of an iron-made armature and a moving translator. The permanent magnets adoption produces parasitic effects, such as cogging force, and the machine weight increment. A solution could be the adoption of an ironless configuration, accepting a power density reduction. This paper investigates the use of ironless PMLGs in sea wave energy conversion systems by an experimental comparative analysis between an iron PMLG prototype and an ironless PMLG prototype, which share the same geometry. The main electrical and mechanical parameters (resistance, mass, and magnetic fie…

A Ferrite Tubular Linear Motor (FTLM): Analysis and design

The electromagnetic linear machines have wide applications in the electromagnetic aircraft launch systems [1] and in transportation systems [2]. Additional energy saving and efficiency can be achieved using a linear motor in the refrigeration application [3]. Linear electromagnetic machines are also very suitable for high-speed packaging, manufacturing sectors and precision positioning. There are different linear motor topologies. Tubular permanent-magnets are particularly attractive since they have a high thrust force density and high efficiency, no end windings, and zero net attractive force between stator and armature. There are various tubular motor topologies, in which the armature may…

Desalination by sea wave in small islands: The case of study of Lampedusa (Italy)

The paper analyses the theme of water energy nexus, investigating a specific industrial process: desalination. In particular, the paper reports a case of study, applied in the small island of Lampedusa, located at south of Sicily (Italy). As the many small islands in the middle of the Mediterranean Sea, Lampedusa presents a small electrical grid, not connected to the mainland. The electrical production is entrusted to old diesel engines, consuming fossil fuel, transported by boat from Sicily. Besides, the renewable energy sources are extremely underdeveloped in this territory, since the environmental constraints make complex the use of technologies, like wind turbines or photovoltaic panels…

Environmental Impact Assessment (EIA) of Wave Energy Converter (WEC)

The Environmental Impact Assessment (EIA) is an environmental management instrument implemented worldwide. In the last years the development of Wave Energy Converter (WEC) influenced environmental research to quantify impacts on marine life. In this paper we present a case study of EIA: a real application and study of device installed in Tirren Sea (near Castellammare — Sicily).

A Review of the Water Desalination Technologies

Desalination is commonly adopted nowadays to overcome the freshwater scarcity in some areas of the world if brackish water or salt water is available. Different kinds of technologies have been proposed in the last century. In this paper, the state of the mainstream solutions is reported, showing the current commercial technologies like reverse osmosis (RO), Multi-Stages Flash desalination (MSF) and Multi-Effect Distillation (MED), and the new frontiers of the research with the aim of exploiting renewable sources such as wind, solar and biomass energy. In these cases, seawater treatment plants are the same as traditional ones, with the only difference being that they use a renewable energy s…

Investigation on a Bio-Composite Material as Acoustic Absorber and Thermal Insulation

In order to limit the anthropic emissions of CO2, research is currently investigating new materials for the building sector. The main purpose is the reduction in the embodied energy consumption, especially in the residential sector, and consequently the limitation of the direct and indirect utilization of fossil fuels, for the indoor heating, cooling, and ventilation services. Indeed, the residential sector is affected by a high energy demand, thus the choice of improved materials is fundamental to improve the sustainability. All phases: construction, building life, and dismantling are impacting in terms of resource and energy consumption, both associated with the emissions of pollutants in…

Testing a linear ironless generator for the sea wave energy harvesting

Wave energy represents a "new entry"in the renewable energy sector; however, it is believed that in near future sea wave might have a key role for the electrical energy production, thanks its huge energy potential. In this context, the paper suggests an innovative ironless linear generator, that can be used as main component inside a point absorber. In order to exploit the wave energy potential in the Mediterranean Sea, the Engineering Department of Palermo University realized a first small-scale prototype of the electrical linear generator, that is the main component for the energy conversion.

Optimization of Wave Energy Converter: DEIM Point Absorber II

The paper presents a possible solution to optimize a wave energy converter, device able to exploit the wave energy resource. The utilization of this technology shows also positive aspects, thanks to the limited visual and environmental impacts. This system could be also installed in reserved areas, being similar to signal buoys, simplifying the problem of energy supply in small islands. In order to exploit the wave energy potential in the Mediterranean Sea, the department of Energy of Palermo University realized a first prototype of the electrical linear generator, that is the main component of the wave energy converter. This electrical machine can be operated by a two-floating buoys system…

Minimization of detent force in a 1 kW linear permanent magnet generator for the conversion of sea waves energy: Numerical and experimental validation

Linear permanent magnet generators are widely considered for the direct conversion of energy contained in sea waves [1-3]. Both planar and tubular structures have been proposed [4-6] and all these structures present several advantages: relative high efficiency, simplicity of the structures, high sturdiness. However, as all other linear machines they present some drawbacks: oscillations in the movement, distortion in the generated electromotive force (emf), etc. In this paper we focus our attention on the parasitic oscillations of the translator which are caused by the presence of a high detent force. Detent force is generated by the fact that magnetic energy presents a minimum when the leng…

A Magnetohydrodynamic Generator for Marine Energy Harvesting

In this article we present an approach to the description of Magneto-hydrodynamic Marine Energy Harvesting (MHMEH) system. Preliminarly, a general discussion on the principle of operation is presented. Successively, in order to move beyond the analytical model, a 3-D MHD modeling tool and a Runge Kutta method based solver are presented and they are used to investigate an alternative MHD solutions. Some numerical analyses are given.

A New Solution for Sea Wave Energy Harvesting, the Proposal of an Ironless Linear Generator

The paper investigates an innovative ironless linear generator, installable inside a wave energy converter, in order to produce electricity from sea waves. This energy source is considered strategic for the future, especially in small islands

Renewable Energy Assessment in Italy and Brazil: An Economic and Political Comparison

The aim of this study is a comparison among Italian and Brazilian electrical energy system with a particular focus on renewable energy sources. The energy sector has a key role in the sustainable development of a country, so it influences economic and political choices. The work would underline differences, common point among two country, specially, in this particular socio-economic period and it should emphasize that green economy could be a possible answer to financial crisis. The main purpose of this study is a presentation of Italian and Brazilian energy system with a particular focus on renewable sources. The energy sector has a key role in the sustainable development of these countrie…

Greening island: Renewable energies mix to satisfy electrical needs of Pantelleria in Mediterranean sea

In this article the authors analyze the renewable mix in order to satisfy the energy needs of a real island in the Mediterranean sea, Pantelleria, which represents an optimal starting point to increase the production of electrical energy from renewable sources in minor islands. In this text are exposed different alternative sources, such as solar, wind and wave energy. Moreover, it is exposed a project of an innovative conversion device proposed by Department of Energy of University of Palermo, compared to a different one proposed by Politecnico di Torino. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in diffe…

Wave and Wind Energy Systems Integration in Vietnam: Analysis of Energy Potential and Economic Feasibility

Vietnam energy demand is currently growing at a very high annual rate, with the government being very interested in investments in renewable energies. Since the region with the highest solar and wind potential is far away from the big load centers, an investigation of offshore energy resources is here proposed. In this study, a review of previous energy potential assessments is provided. Moreover, the minimum feed-in-tariff to make the investments profitable is evaluated, showing that the current tariff for offshore wind plants is largely unattractive.

The effect of manufacturing tolerances on a tubular linear ferrite motor

This study presents a numerical and experimental study on the effect of permanent magnet tolerances on the performances of a Tubular Linear Ferrite Motor. The statistical distribution of the magnetic characteristic of a set of commercial magnets is obtained experimentally while the performances of a the tubular motor are numerically evaluated. The performances that have been considered are: cogging force, end effect force and generated thrust. It has been shown that: 1)the statistical variability of the magnets modifies the time behavior of the cogging force; 2)the value of both the end effect cogging force and the generated thrust are directly linked to the values of then remanence field o…

An electromagnetic generator for MAGLEV transportation systems

The fundamental idea of this paper is to use the distribution theory to analyze linear generators in order to include in the mathematical model both ideal a non ideal features. This paper shows how the use of distribution theory can be used in order to establish a mathematical model able to describe both the ordinary working condition of a linear generator for MAGLEV systems as well the role of the unavoidable irregularities and non-ideal features.

A small scale prototype of a wave energy conversion system for hydrogen production

In this paper a small scale prototype of sea wave energy converter for hydrogen production and storage is presented. Laboratory prototypes of the wave energy converter device and sea water electrolyzer are presented. Experimental results are shown. A cost-effective and efficient power electronics system is designed. Experimental waveforms of the wave energy converter are imported in the power electronics simulation model to simulate the whole system as closely as possible to its effective behavior. Simulation results are shown to test the efficiency of the proposed solution.

Reduction of cogging force in linear generators for wave energy harvesting

Due to huge energy potential of sea waves, many technologies have been proposed in the last few years. Some concepts have been developed and sometimes also tested in the open sea. Some prototypes use linear generators to directly convert the vertical motion of buoys into electrical energy. This solution minimizes the numbers of energy conversion steps, increasing the energy efficiency. At the same time, the limited numbers of components could also increase the reliability of the wave energy converter. For this reason, the development of linear generators is considered with great interest. This paper investigated the cogging force, a magnetic force due to the interaction between the magnets …

Sustainability of the Renewable Energy Extraction Close to the Mediterranean Islands

The aim of this work is to explore the possibility of transitioning a fuel powered island to a renewable powered one. This transition is analyzed for the real MV/LV distribution system of the island of Pantelleria, in the Mediterranean Sea. Particularly, this work is focused on a renewable source nowadays totally unused: wave energy. Thanks to the innovative generator prototype designed by Department of Energy of University of Palermo (Italy), wave energy is able to represent a primary source for the production of electric energy in the Mediterranean islands. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in di…

Investigating energy saving potential in a big shopping center through ventilation control

Abstract This paper investigates energy saving measures for the ventilation system of large shopping centers. This kind of buildings is characterized by high yearly energy consumptions, because of the high level of operating hours and the frequent use of obsolete technologies. In the analyzed case studies, three big Do It Yourself (DIY) shops, located in Italy, are considered. Two different approaches are considered, they are aimed at reducing the annual energy consumption for the indoor air exchange of the sales area. The first considered retrofit solution consists in the installation of heat recovery exchangers, reducing the energy demand for the air thermal treatment without changing the…

Energy Saving in Public Transport Using Renewable Energy

Hydrogen produced by renewable sources represents an interesting way to reduce the energetic dependence on fossil fuels in the transportation sector. This paper shows a feasibility study for the production, storage and distribution of hydrogen in the western Sicilian context, using three different renewable sources: wind, biomass and sea wave. The objective of this study is the evaluation of the hydrogen demand, needed to replace all diesel supplied buses with electrical buses equipped with fuel cells. An economic analysis is presented with the evaluation of the avoidable greenhouse gas emissions. Four different scenarios correlate the hydrogen demand for urban transport to the renewable en…

Supplying small islands with solar, wind and sea wave. An economic approach to find the best energy share

The progressive installation of power plants based on renewable energy sources is improving the sustainability of the energy sector. Despite the availability of commercial solutions, most of the small islands in the world are nowadays affected by a deep dependence on fossil fuels. In this context, the paper investigates the feasibility of an energy mix composed by solar, wind and sea wave, suggesting a sizing approach based on the minimization of the Levelized Cost of Electricity of the entire energy mix. As case study, the Aeolian Islands are presented.

Designing an innovative system for sea wave utilization

For the sea wave energy exploitation, the department of Energy of Palermo University is investigating a new approach based on the mechanical motion conversion from a linear motion into a unidirectional rotary motion. This mechanical output can be used to run alternators, producing electrical power with a very simplified energy conversion chain. First preliminary tests have been realized in laboratory using a small-scale prototype.

Assessment of Renewable Sources for the Energy Consumption in Malta in the Mediterranean Sea

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…

Renewable energy sources to fulfill the global energy needs of a country: The case study of Malta in Mediterranean Sea

The paper shows the advantages using different energy resources for the islands of Malta. Moreover, this work is focused on the analysis of the wave energy potential along Malta's coasts. This important resource can be exploited to produce electrical energy using an innovative Point Absorber based on a new generator prototype realized by University of Palermo. The use of renewable source will reduce greenhouses emissions and increase the energy independence of Malta. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in different technical fields that show a good replicability [1]-[7].

Numerical simulation of wave energy production through experimental tool

Wave energy is highly desirable resource and recent international reports underline its major relevance on global renewable energy in future. In general, the first step is a correct WEC (Wave Energy Converter) sizing and design. The aim of this paper is a presentation of an application of one experimental tool to define the external floating structure of WEC realized by University of Palermo. This new electric device could be another energy possibility for small islands in the Mediterranean Sea as Pantelleria, Lampedusa or Malta.

Sea wave energy to supply the Aeolian Islands in sustainable way

The diffusion of technologies supplied by Renewable Energy Sources is contributing in the challenge of reduction of energy dependence from fossil fuels, avoiding the emission of several polluting substances and greenhouse gases. Despite the technological development and important results around the world, in several remote areas or small islands the electrical energy production is based on obsolete technologies, supplied by fossil fuels. This solution is not sustainable for the environment, as the emissions of several pollutants. Focusing the attention on small islands, these areas usually have a standalone grid, as the high cost to build an electrical connection to the mainland, in compari…

Investigating Energy Saving Potential in a Big Shopping Centre through Ventilation Control

This work shows an example of energy saving interventions on the ventilation system of a big shopping center. This kind of buildings is characterized by high energy consumptions, because of the high level of yearly operating hours and the use of obsolete technologies. In the case study, a big Do It Yourself (DIY) shop located in the southern part of Italy is analyzed, proposing two different approaches aimed at reducing the annual energy consumption for the indoor air exchange of the sales area. In the AS-IS scenario, a centralized HVAC plant, composed by six rooftops, is installed on the roof of sales area, working with fixed airflow value. The first retrofit solution involves the installa…

Environmental sustainability in non-residential buildings by automating and optimization LENI index

Directive 2002/91 / EC as amended by 2010/31 / EU introduces procedures for energy certification aimed to determine, through the numerical indicators, the overall energy efficiency of the buildings, but notes the thermal and electric consumption. Often, the power consumption is incorrectly underestimated, this consumption would to be considered with great attention. In fact, compared to a committed capacity of less, compared to thermal plants, have times of utilization often far higher, leading to energy requirements to levels similar or even higher than those thermal, being the conversion factor of the electrical energy increasingly high. Leaving aside the procedural scheme energy certific…

Experimental tests on hydrogen production from seawaves energy

In this paper we propose the use of Wave Energy Converter and saline water to produce hydrogen. Two different scheme and technology are proposed. The objective of this research is to design an electrolyzing system capable of utilizing sea. In particular, we present the results obtained by two different prototype of electrolyzer: one with steel electrodes and the second with titanium electrodes. Further experiments were carried out by changing the electrolytic solution of water and sodium chloride in real seawater. Finally, the electrical load has been changed as imposing electric current with a distorted waveform. © 2017 Marine Technology Society.

Flexibility Services to Minimize the Electricity Production from Fossil Fuels. A Case Study in a Mediterranean Small Island

The design of multi-carrier energy systems (MESs) has become increasingly important in the last decades, due to the need to move towards more efficient, flexible, and reliable power systems. In a MES, electricity, heating, cooling, water, and other resources interact at various levels, in order to get optimized operation. The aim of this study is to identify the optimal combination of components, their optimal sizes, and operating schedule allowing minimizing the annual cost for meeting the energy demand of Pantelleria, a Mediterranean island. Starting from the existing energy system (comprising diesel generators, desalination plant, freshwater storage, heat pumps, and domestic hot water st…

Wave Energy Assessment along Sicilian Coastline, Based on DEIM Point Absorber

The use of renewable energy sources is one of the most relevant goals to be achieved in order to match the climate protection targets. As a case study, the paper shows the current electrical energy production by sources in the Sicilian context. Among the renewable energy sources, the paper investigates the wave energy potential along the Sicilian coasts, because of the favorable climate around the island. A point absorber is present in order to exploit this source. Two scenarios are presented, with two different levels of energy production.

Grid Stability Improvement Using Synthetic Inertia by Battery Energy Storage Systems in Small Islands

In this paper, the synthetic inertia need of the small island of Pantelleria in the Mediterranean Sea is assessed. Firstly, the optimal renewable energy mix able to minimize the Levelized Cost of Energy for the generation system of the island is evaluated, considering the yearly load demand and the characteristics of the local natural resources. The optimal energy mix introduces in the island a quota of power generation with static power converters interfaced to the grid that could jeopardize the security of the system if not suitably controlled. Therefore, the inherent inertial response of the diesel generators of the system is calculated hour by hour for each month of one year, considerin…

Experimental validation of a distribution theory based analysis of the effect of manufacturing tolerances on permanent magnet synchronous machines

An experimental study on the effect of permanent magnet tolerances on the performances of a Tubular Linear Ferrite Motor is presented in this paper. The performances that have been investigated are: cogging force, end effect cogging force and generated thrust. It is demonstrated that: 1) the statistical variability of the magnets introduces harmonics in the spectrum of the cogging force; 2) the value of the end effect cogging force is directly linked to the values of then remanence field of the external magnets placed on the slider; 3) the generated thrust and its statistical distribution depend on the remanence field of the magnets placed on the translator.

Optimization of cogging force in a linear permanent magnet generator for the conversion of sea waves energy

In this paper an approach to the optimization of cogging force in a linear permanent magnet generator for the conversion of sea waves energy is presented. We have optimized the cogging force of a linear permanent magnet generator by using a 3D FEM parametric simulation. Several possible design solutions have been computed. A generator has been built and the results of the minimization procedure has been experimentally validated.

Sea Wave Energy. A Review of the Current Technologies and Perspectives

The proposal of new technologies capable of producing electrical energy from renewable sources has driven research into seas and oceans. Research finds this field very promising in the future of renewable energies, especially in areas where there are specific climatic and morphological characteristics to exploit large amounts of energy from the sea. In general, this kind of energy is referred to as six energy resources: waves, tidal range, tidal current, ocean current, ocean thermal energy conversion, and saline gradient. This review has the aim to list several wave-energy converter power plants and to analyze their years of operation. In this way, a focus is created to understand how many …

First analyses on a mechanical motion converter to produce electrical energy from sea wave

The exploitation of sea wave opens new horizon for suppling small islanded communities. With this goal the paper propones a prototypical device for the utilization of sea wave along the coastline. The device is based on a mechanical motion conversion, from an alternative rotation into unidirectional rotation in order to run commercial generators. First evaluations are here reported, demonstrating the feasibility of this solution.

A Planar Generator for a Wave Energy Converter

This article presents a permanent magnet planar translational generator which is able to exploit multiple modes of sea wave energy extraction. Linear electrical generators have recently been studied for the exploitation of sea wave energy, but, to the best of our knowledge, no synchronous planar translational generator has been proposed. In this article, to maximize the energy extraction, we have considered all the potential modes of motion due to wave excitation and included them within the mathematical model of the proposed system. The principle of operation of the generator can be summarized as follows: the moving part (translator) of the generator is driven from the sea waves and induce…

Energy Saving Optimizing the Ventilation Control in a Big Shopping Center

The paper investigates the potential energy savings in the context of big shopping centers, thanks to the introduction of innovative technologies able to control the ventilation according the real requirement for comfort and health of indoor spaces. The case study analyses a big shopping center, where the ventilation is realized with a centralized air-conditioning plant, working with fixed air flows. Two solutions are proposed to reduce the energy consumption for ventilation. The first considers the installation of heat recovery exchangers, the second the introduction of a control system able to modulate the air exchange, according to the real requirements. An energetic and economic evaluat…

The role of the effect of manufacturing tolerances on a tubular linear ferrite motor

Electric machines are often designed without considering workmanship and materials tolerances. Their manufacturing process involves a series of steps, starting with raw materials and ending with the machine assembly. In each of these steps occur deviations due, for instance, to mistakes in positioning tools or to the tolerances in the electrical and magnetic characteristics of the materials. These deviations may cause unwanted parasitic effects such as torque ripple, losses or acoustic noise. Such effects have to be considered especially in machines used in industrial drives for high performance applications. Moreover the tolerances in the magnetic materials have a considerable effect on th…

Power Conversion System for Improved Linear Generator in sea wave energy harvesting applications

Nowadays, many islands worldwide are lack of electrical energy. Thus, it is convenient to exploit available renewable energy sources, among which sea waves near the islands. This paper focuses on the power conversion system coupled with an offshore wave energy device, such as an improved linear generator, to be used for sea wave energy harvesting. Particularly, the design of the linear generator has been proposed to improve the energy efficiency of the entire system. The proposed power conversion system is composed by two Boost Rectifier (BR) directly coupled to the linear generator, and one Voltage Source Inverter (VSI), which it is used as front-end between the DC-bus and the grid. The pr…

Near zero energy island with sea wave energy: The case study of Pantelleria in Mediterranean Sea

In this paper the authors present a study of the transition of an energy generation system for a real MV/LV distribution system from one that is "fuel-based" to a "renewables-based" system in particular from sea wave energy, using the data acquired from an innovative generator prototype realized by University of Palermo. The study is carried out for a real islanded network located in the Island of Pantelleria (Mediterranean Sea). The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in different technical fields that show a good replicability [1]-[7].

Introduction of Offshore Wave, Wind and Solar Energies in Vietnam

In Vietnam, the energy demand shows an ever-increasing trend. To limit the utilization of fossil fuels and the following consequences for the environment, renewable energy sources must be adopted. In this context, the paper assesses the utilization of offshore wind and sea wave, by considering a commercial wind turbine and a prototypical wave energy converter. Solar energy can be optionally also collected by this device. An algorithm is introduced to find the best composition of the three sources able to cover a desired share of energy demand. The approach is applied to Ca Mau, a province in the southern part of Vietnam. Finally, the results encourage the adoption of these energy sources th…

An innovative mechanical motion converter for sea wave applications

The paper shows an innovative system designed and developed by University of Palermo. The device is based on a simple mechanical converter able to transform a variable bidirectional linear motion into a unidirectional rotary motion. This technology can be successful used in sea wave applications, producing a mechanical output usable for the electrical energy production.

A sustainable energy production: Sea Wave in the small island of Ustica (Italy)

Nowadays the electrical energy production is based on fossil fuels in the greatest part of smaller islands in the Mediterranean Sea. Despite the availability, the renewable energy sources are practically unused, as landscape constraints. So, the paper presents the case of study of Ustica, a small island located at north of Sicily, in the middle of Mediterranean Sea. Starting with the analysis of the electrical energy consumption of public buildings, the paper suggests an energetic scenario, based on solar and sea wave. In particular, in order to use this new resource, the paper presents an innovative wave energy converter. Finally, the energetic and economic evaluations encourage the realiz…

Greening and sustainable energy approach applied for Balearic Islands and Fiji Islands: a comparative study

Renewable energy sources are expanding around the world, with significative results in the electricity generation sector. Despite this, the share of renewable energy sources in small islands is very low, except in rare cases. In this context, the paper analyses the energy mix currently used to produce electricity in the Balearic Islands and the Fiji Islands. These two archipelagos show several differences but have in common the strong energy dependence from fossil fuels. In order to increase the energy sustainability of small islands, a preliminary energy assessment is realized, using climate data collected from GIS-tools and introducing a numerical approach. As target, the Authors consider…

A Preliminary Energy Assessment to Improve the Energy Sustainability in the Small Islands of the Mediterranean Sea

Power plants supplied by renewable energy sources are expanding around the world, in order to reduce the carbon dioxide emissions, limit the global warming and improve the energy sustainability. Despite the relevant achieved results, small islands are heavily reliant on fossil fuels. In this context, renewable energy sources are available but practically unused, due to landscape and economic constraints. This condition is quite common in the Mediterranean Sea. These islands are normally fed by a stand-alone electrical grid and a power plant, equipped with diesel engines. In order to improve the sustainability of the energy sector, the paper considers the case study of Ustica, a small Italia…

A computational magnetohydrodynamic model of a marine propulsion system

In this article we present an approach to the description of Magnetohydrodynamic Propulsion. Preliminarly, an analytical model which includes an electromagnetic model and a thermal model is presented. Successively, in order to move beyond the analytical model, a 3-D MHD modeling tool and a Runge Kutta method based solver are presented and they are used to investigate an alternative MHD solutions. Some numerical analysis are given.

Energetic Sustainability Using Renewable Energies in the Mediterranean Sea

The paper is focused on the analysis of the electrical energy sector in the Maltese islands, focusing on the employment of Renewable Energies in order to increase its energy independence. The main renewable source here proposed is wave energy: thanks to its strategic position, Malta will be able to generate electrical energy through the use of an innovative type of Wave Energy Converter (WEC) based on the prototype of linear generator designed and developed by the University of Palermo. 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 photovoltai…

A Simulation Analysis of VSM Control for RES plants in a Small Mediterranean Island

The paper presents an application of Virtual Synchronous Machine control for managing inverter-interfaced renewable energy sources in a small Mediterranean island not supplied by the main grid. In the proposed analysis, the island's renewables-based generators area assumed interfaced to the grid by voltage source converters with a swing controller and a vector-current controller with two different options for the reference current for regulating the voltage at the Point of Common Coupling and the active power output. The system, modeled in PScad environment, allows to verify the response of the renewables-based generators with VSM control in the presence of a fault in the grid.

Design of wave energy converter (WEC): A prototype installed in Sicily

The purpose of this work is to describe a possibility of installation of a wave converter in Sicily, in the Mediterranean Sea. In this paper we present the design of buoyant electrical generator, in particular, wave linear permanent magnet generator which can make wave energy converted to electrical energy.

A linear generator for a waveroller power device

In this paper experimental tests on a small scale tubular linear generator to be applied to wave rollers device are presented. A reduced scale of gnerator is presented and experimental results obtained in on test bench are shown. Experimental waveforms of current and voltage are recorded. Simulation results are compared to the experimental ones in order to validate the mathematical models used.

Evaluation of an integrated energy system in the Park of Madonie

This paper analyses technical and economic aspects relative to a hypothetical wind farm installed inside the park of Madonie (Sicily) that produces electric energy for the direct use and to supply an electrolytic system for the production of hydrogen. User is formed by approximately 20,000 persons who live in the mountain localities of the park. Global energy required by user was estimated carrying out hypotheses on daily power demand. Discontinuous power makes inescapable to connect wind farm to grid, so that energy demand of user is partially satisfied by means of energy wind, while the remaining part becomes from grid. Surplus of power that turbines make available when wind speed is part…

Evaluation of the optimal renewable electricity mix for Lampedusa island: The adoption of a technical and economical methodology

Abstract Worldwide, the majority of small islands not connected to the main grid is still dependent on fossil fuels. From an economic and environmental point of view, this condition is no more sustainable given the high costs for electricity generation and the high level of pollutant emissions. Furthermore, the dependence on fossil fuel represents a risk for the security of the supply of several small developing Countries since they are obliged to import those resources from foreign Countries. The introduction of renewable energy sources in small islands represents a valid solution to solve these problems. In this context, the paper investigates the case of Lampedusa, a small Italian island…

Stability Analysis in a Vietnam Small Island for the Deployment of a Nearshore Wave Power Plant

The requirement for a more sustainable energy mix is promoting the spreading of technologies supplied by renewable sources. However, the introduction of unprogrammable energy sources in small electrical grids could jeopardize the stability of the entire system. In this context, the paper analyses a small island in Vietnam, assessing the effects due to the installation of a new power plant supplied by sea wave energy. While the installation of this technology could represent a great opportunity to reduce the local energy dependence, on the other side the quality of the supply could be worsened. Solutions are assessed to allow a good network service.

DESALINATION AND SEA WAVE TO PRODUCE FRESHWATER AND ENERGY FROM THE SEA. THE PROPOSAL OF A LINEAR GENERATOR FOR A WAVE ENERGY CONVERTER AND EVALUATION OF CASE STUDIES IN SMALL ISLANDS

A Magnetohydrodynamic Auxiliary Propulsion system for docking assistance of autonomous vehicle

In this article we present an approach to the description of Magnetohydrodynamic Auxiliary Propulsion system for docking assistance of autonomous vehicle. Preliminarily, an analytical model which includes an electromagnetic model and a thermal model is presented. Successively, in order to move beyond the analytical model, a 3-D MHD modeling tool and a Runge Kutta method based solver are presented and they are used to investigate an alternative MHD solutions. Some numerical analysis are given

The helicoidal magnetic generator

Recently helicoidal generator for the exploitation of sea wave energy has been proposed. This device can convert both the vertical and rotational movement of seawaves. The electrical energy generated by such a device must be converted and conditioned in order to match the instantaneous utility requirements and a power link from the sea to an interconnection is needed. In this paper, the authors propose a mathematical model of this device and preliminarily present a prototype of the machine.

A renewable energy mix to supply small islands. A comparative study applied to Balearic Islands and Fiji

Abstract Power plants supplied by renewables are expanding around the world, increasing the sustainability of the energy sector. In this context, small islands are heavily reliant on fossil fuels. However, this paper shows that the same problem can be found also in small islands belonging to developed countries. To increase the energy sustainability of small islands, the authors assembled a simplified mathematical approach to evaluate the potential electricity production, exploiting the local available energy sources: solar, wind and sea wave. The mathematical model requires few information in input, such as climatic data about the local energy sources and technical features on the selected…

Energy Retrofit. A Case Study—Santi Romano Dormitory on the Palermo University

Electrical and thermal consumption related to buildings, whether civil, commercial, public, or of any other kind, is very much in focus today. With today’s targets for energy savings, reduction of consumption, and environmental impact, it is necessary to carry out energy retrofits to modernize installations and their management. The realization of an effective improvement requires a careful analysis of the case study because each category of building has different requirements such as different load profiles and different installations and needs. This was carried out by studying the electrical and thermal load profiles. A good initial energy audit can provide the retrofit solutions capable …

FEM Analysis: A Review of the Most Common Thermal Bridges and Their Mitigation

The necessity to improve the energy saving potential of buildings is now a duty. European and national policies are being implemented to address the important decisions being made on this subject. For these reasons, several studies focus on this relevant topic. This paper review not only focusses on it but studies it in-depth. A commercial 3D simulation software was used to design a building sited in Palermo estimating the thermal losses before and after external envelope insulation. In particular, all the thermal bridges (TBs) were analysed with the finite element method (FEM) and mitigated with rock wool insulation. The paper shows the linear thermal transmittance difference and heat flux…

Nexus Water & Energy: A Case Study of Wave Energy Converters (WECs) to Desalination Applications in Sicily

The recent studies about interactions among energy and water are considered as a new field of research. As almost all energy generation processes require significant amounts of water, and water requires energy for treatment and transport, so these two resources are inextricably linked. The main aim of this work is a presentation of the use of renewable energy for desalination plants in Sicily: in particular exploitation of wave energy into electrical energy necessary for water treatment. Desalination is the most energy intensive water treatment technology but it could be solution for many problems in water supply for areas with chronic debt of water. In this study we find three section: in …

Energy savings for indoor lighting in a shopping mall: A case of study

The paper presents an application of energy saving in the final users. In particular, the case of study evaluates the energy consumptions of a big shopping mall, located in the middle part of Italy, illuminated by fluorescent lamps. In order to reduce the energy demand, the case of study shows a first solution based on LED lamps; a second step considers the adding of a building automation system, maximizing the energy saving, thanks lighting sensors that module the luminous flux taking in count of natural lighting through skylights.

Sea water desalination and energy consumption: A case study of wave energy converters (WEC) to desalination applications in sicily

Recent studies about interactions among energy and water are considered as a new field of research. As almost all energy generation processes require significant amounts of water, and water requires energy for treatment and transport, so these two resources are inextricably linked. The main aim of this work is a presentation of the use of renewable energy for desalination plants in Sicily: in particular exploitation of wave energy into electrical energy necessary for water treatment. Desalination is the most energy intensive water treatment technology but it could be solution for many problems in water supply for areas with chronic debt of water. The aim of this work is a description of a s…

Control systems for indoor lighting and computer simulation: analysis and comparison between software packages capabilities and results on a real case study

In the last years, computer capabilities have evolved rapidly and also the way to simulate building physics phenomena is changed and more developed. Each simulation software is developed with a less or more similar aim, using different algorithms and models and being used by people with different profile: specialist, architects, engineers, installers, etc. This paper deals with the analysis of capability of some of the most utilised software used to predict indoor lighting, including natural daylight contribution and assessment of energy consumption and savings related to specific design options. Furthermore, two of the analysed software have been tested simulating a case studying. Results …

An Economic Approach to Size of a Renewable Energy Mix in Small Islands

The importance of renewable energy exploitation reduces the energy dependence on fossil fuels. Despite technological progress, in several remote areas and small islands the energy production is nowadays dominated by the utilization of fossil fuels. With new, increasingly stringent laws on polluting emissions and the need to lower production costs, it is necessary to exploit as many renewable sources as possible. In order to implement these considerations, it was decided to study renewable energy production. The study was carried out by estimating the energy production on a monthly and annual basis considering a mix of three plants, namely marine, solar, and wind. Simulations on wave product…

Guidelines proposal for a good and durable WEC design

In this paper, preliminarily a proposal for design guidelines for a “good” design of wave energy converter is presented and successively a small scale prototype of a wave energy converter including the buoyant electrical generator, the power electronics equipment and a sea water electrolyzer is designed on the basis of these guidelines and presented.

The Desalination Process Driven by Wave Energy: A Challenge for the Future

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) devic…

A Renewable Energy mix to Supply the Balearic Islands: Sea Wave, Wind and Solar

The paper investigates the status of the electrical energy sector in the Balearic Islands (Spain). In order to improve the energetic sustainability, this work analysis the availability of renewable energy sources, focusing the attention on sea wave, wind and solar. For the utilization of sea wave source, an innovative device is proposed.

Hydrogen Production from Sea Wave for Alternative Energy Vehicles for Public Transport in Trapani (Italy)

The coupling of renewable energy and hydrogen technologies represents in the mid-term a very interesting way to match the tasks of increasing the reliable exploitation of wind and sea wave energy and introducing clean technologies in the transportation sector. This paper presents two different feasibility studies: the first proposes two plants based on wind and sea wave resource for the production, storage and distribution of hydrogen for public transportation facilities in the West Sicily; the second applies the same approach to Pantelleria (a smaller island), including also some indications about solar resource. In both cases, all buses will be equipped with fuel-cells. A first economic a…

Flexibility Services in a Mediterranean Small Island to Minimize Costs and Emissions Related to Electricity Production from Fossil Fuels

In last years, the energy efficiency in non-interconnected islands became an important topic, since the electricity production is often based on diesel generators, thus contributing to the global warming. Italian government recently emitted two decrees to promote the introduction of renewable energy technologies in 21 non-interconnected islands, both for electrical and thermal uses. In this paper, the economic and environmental feasibility of the introduction of renewable energies in the island of Pantelleria was assessed adopting an optimization approach. Furthermore, the flexibility provided from the local desalination plant and the domestic water heaters was evaluated. The final demands …

First Life Cycle Impact Considerations of Two Wave Energy Converters

The work presents two different revolutionary devices for the utilization of a new entry of renewable energy sources: sea wave. The first technology is based on linear generators, able to directly converts a linear motion into electrical output, limiting to minimum the chain of energy conversion. The other solution is based on a mechanical motion converter, coupled with alternators. The scope of this paper is to compare the two different systems designed by University of Palermo, through Life Cycle Assessment, in order to evaluate the global effects of the two systems to the environment.

A Permanent Magnet Linear Generator for the Enhancement of the Reliability of a Wave Energy Conversion System

In this paper, a linear generator for a highly reliable Wave Energy Conversion system is designed and tested. In order to store energy, the system is able to produce hydrogen The Wave Energy Conversion System consists of an electrical linear generator, a power conversion system and a sea-water electrolyzer. A small scale prototype of the system has been designed and built. The design is oriented to the enhancement of the system robustness and reliability and a Failure Mode and Effects and Criticality Analysis (FMECA) has been used. In order to guarantee an easy extension of the power capability of the marine plant, a modular architecture of the system has been adopted. The design strategy i…

Improvement of Energy Efficiency for Indoor Lighting in a Big Shopping Center

As the progressive diffusion of shopping centers in Italy, the paper analysis the potential energy savings in the indoor lighting plant, thanks to new technologies as LED lamps and Building Automation System. The case study, applied to a big shopping mall in the middle of Italy, shows great results, thanks to the high efficiency of LED technology, high number of operating hours and the implementation of a control system. An economic and environmental evaluation is reported.

Improving energy efficiency of commercial buildings by Combined Heat Cooling and Power plants

Abstract Commercial buildings play a key-role in the energy consumption of the building sectors. Recent statistics have shown that as the number of commercial buildings is continuously increasing, their effects on energy consumption are expected to grow. These buildings are characterized by high energy demand mainly due to lighting and HVAC requirements. Rooms of energy saving exist by considering that: (i) electricity demands and HVAC requirements occur simultaneously during the day and (ii) both demands are currently satisfied by using separate energy systems. It is apparent that the adoption of polygeneration systems could represent a valid solution to achieve energy savings. To this aim…

Review on Life Cycle Assessment of Solar Photovoltaic Panels

The photovoltaic (PV) sector has undergone both major expansion and evolution over the last decades, and currently, the technologies already marketed or still in the laboratory/research phase are numerous and very different. Likewise, in order to assess the energy and environmental impacts of these devices, life cycle assessment (LCA) studies related to these systems are always increasing. The objective of this paper is to summarize and update the current literature of LCA applied to different types of grid-connected PV, as well as to critically analyze the results related to energy and environmental impacts generated during the life cycle of PV technologies, from 1st generation (traditiona…