This chapter discusses leading problems linked to energy that the world is now confronting and to propose some ideas concerning possible solutions. Oil deserves special attention among all energy sources. Since the beginning of 1981, it has merely been continuing and enhancing the downward movement in consumption and prices caused by excessive rises, especially for light crudes such as those from Africa, and the slowing down of worldwide economic growth. Densely-populated oil-producing countries need to produce to live, to pay for their food and their equipment. If the economic growth of the industrialized countries were to be 4%, even if investment in the rational use of energy were pushed to the limit and the development of nonpetroleum energy sources were also pursued actively, it would be extremely difficult to prevent a sharp rise in prices. It is evident that it is absolutely necessary to pursue actively the development of coal, natural gas, and nuclear power if a physical shortage of energy is not to block economic growth.

World energy outlook

Finite element methods for Maxwell's equations.

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 energy resources present in the territories and to the modern technologies available for the production of hydrogen. The study focuses on the possibility of tapping into the potential of renewable energies (wind, biomass and sea wave) for the production of hydrogen by electrolysis. The use of hydrogen would reduce significantly the emissions of particulate and greenhouse gases in the urban districts under analysis.

/pdf/energy-saving-in-public-transport-using-renewable-energy-2z1v2l63ah.pdf

Energy Saving in Public Transport Using Renewable Energy

The need for energy-efficient and environmentally friendly refrigeration, heat pumping, air conditioning, and thermal energy harvesting systems is currently more urgent than ever. Magnetocaloric energy conversion is among the best available alternatives for achieving these technological goals and has been the subject of substantial basic and applied research over the last two decades. The subject is strongly interdisciplinary, requiring proper understanding and efficient integration of knowledge in different specialized fields. This review article presents a historical and up-to-date account of the energy-related applications of magnetocaloric materials and information about their processing and magnetic fields, thermodynamics, heat transfer, and other relevant characteristics. The article also discusses the conceptual design of magnetocaloric refrigeration and power generation systems and some guidelines for future research in the field.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/aenm.201903741

Energy Applications of Magnetocaloric Materials

Predictive performance tools are an important factor in the success of any new technology because they permit demonstration of whether a system will be efficient and economically feasible. A reliable predictive tool should allow the designer to optimise system performance and to maximise the cost effectiveness of a system prior to installation. This article discusses the five main parametric models for photovoltaic (PV) systems available in the literature. The current–voltage characteristics of a photovoltaic module can be reproduced modelling the PV panel as an equivalent electrical circuit made of linear and non-linear components. The parameters describing such components are directly related to the performance characteristics of the specific PV panel, which are generally available in a graphic form with respect to standard values of temperature and incident irradiance. Five of the most recent models are analysed in detail describing the algorithm, showing how the parameters were determined and highlighting the most important mathematical and physical assumptions that characterised each model and the calculation process. To simplify the examination and reading of the procedures referred to in the five models, all equations are rewritten using the same nomenclature. Furthermore, to assess the accuracy of each model with respect to the data provided by the manufacturer, this paper compares the I–V and P–V curves at various temperatures and irradiance for a generic PV panel.

A comparison of different one-diode models for the representation of I–V characteristic of a PV cell

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.

https://www.mdpi.com/1996-1073/9/12/1032/pdf

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

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 analysis is presented together with the assessment of the avoidable greenhouse gas emissions during the operation phase. The scenarios addressed permit to correlate the demand of urban transport to renewable resources present in the territories and to the modern technologies available for the production of hydrogen from renewable energies. The study focuses on the possibility of tapping the renewable energy potential (wind and sea wave) for the hydrogen production by electrolysis. The use of hydrogen would significantly reduce emissions of particulate matter and greenhouse gases in urban districts under analysis. 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.

https://www.mdpi.com/1996-1073/9/10/850/pdf

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

In this paper, we present a transverse flux linear generator. We investigate the possibility to use this generator to extract energy from seawaves. We propose an optimization procedure that allows us to obtain an optimized design of the generator. The optimized design of the converter shows a power generation capability index much higher than other renewable systems.

/pdf/design-of-a-transverse-flux-machine-for-power-generation-5163ga6l36.pdf

Design of a transverse flux machine for power generation from seawaves

In this paper Preisach Model is applied to obtain a mathematical model of the hysteresis in lithium battery. Preisach Model allows to describe the hysteresis of charging and discharging cycles in a lithium battery. The identification of the model is obtained by using a neural network technique developed for magnetic systems. The model is verified on some experimental tests on commercial batteries.

Description of Hysteresis in Lithium Battery by Classical Preisach Model

The use of bioclimatic principles can reduce energy demands and CO2 emissions in the building sector [1-. Costs are one of the most important barriers to a widespread adoption of the green architecture technologies [4-. The aim of this study is to compare the energy and economic performances of two buildings: a real residential bioclimatic building located in Cinisi (a small town near Palermo, Sicily) and an imaginary residential building supposed having the same geographical location, cubature, shape and orientation as the bioclimatic building but built by conventional building materials. The tools used for this study were TRNSYS and HOMER

Alessia Viola

Papers

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

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

Design of a transverse flux machine for power generation from seawaves

Description of Hysteresis in Lithium Battery by Classical Preisach Model

Energy and Economic Comparison of Different Conditioning System among Traditional and Eco-Sustainable Building