• Energy Research
• Restricted close
• Open Source close
• 7. Clean energy close
• 13. Climate action close
• 1. No poverty close
• Aurora Universities Network close

Dolomite-based binders are characterised by interesting technical and environmental features. For their synthesis, sources of both CaO and MgO are required. The idea developed in this work is to couple the synthesis of dolomite-based binders, starting from a natural dolomite, through the concept of concentrated solar energy (needed to drive the endothermal dolomite calcination process) in fluidised bed reactors. To this end, a fluidised bed system, where the concentrated solar radiation is mimicked by the use of Xe-lamps (short-arc), has been set up and operated. Natural dolomite (sieved in the 420-590 ?m size range) was calcined at a nominal temperature of 850 °C, and bed temperature profiles during solar-driven calcination were investigated. Then, four binders were prepared by mixing slaked dolomite (obtained from the hydration of solar calcined dolomite) with either blast furnace slag or coal fly ash as supplementary cementitious materials. The binders were hydrated for curing times ranging from 7 to 56 days. X-ray fluorescence, X-ray diffraction and combined differential thermal and thermogravimetric analyses were employed as characterisation techniques both to analyse the chemical composition of starting materials and to investigate the evolution of the hydration in the four systems.

In this paper a grid-tied photovoltaic (PV) cascaded H-bridge (CHB) inverter with embedded storage units is proposed. The multi-input single-output inverter architecture allows a distributed maximum power point tracking (DMPPT) approach, thus mitigating the mismatch effects. The energy storage units (ESUs) embedded at each dc-link provides more flexibility to the power circuit compensating for the inherent variability of the PV sources. The proposed power system ensures a continuous power supply to the grid also in case of PV power fluctuations due to irradiance conditions as well as to the MPPT. In particular, the presence of a storage element allows a voltage sweep on the PV source to be implemented, thus guaranteeing the maximization of PV energy harvesting, with no detrimental effect on the power delivery to the utility network. The numerical results, carried out on a single-phase nineteen-level PV CHB inverter, reveal the improved performance of the proposed design and control technique.

The safeguard of power equipments is assuming a major role in the deregulated electricity market, where a malfunctioning power system could be responsible for serious damages to a large number of system operators having access to the shared energy resource. In this context thermal monitoring of power cables represents a key issue in evaluating the risks associated with a given load management policy especially during emergency conditions. In particular this demands for reliable assessment models that should be able to predict the transient thermal behaviour when the load exceeds the nameplate value. In this connection the application of both simplified and detailed power cable thermal models is often complicated by the presence of uncertainties affecting the tolerances of the input data. The effect of these uncertainties could influence the final solution to a considerable extent. A comprehensive tolerance analysis is therefore required in order to incorporate the effect of data uncertainties into the thermal modelling process. To address this problem, in the paper the employment of interval mathematic is proposed. Several numerical results are presented and discussed in order to assess the effectiveness of the proposed methodology which offer a rough qualitative insight of the solution in a very short time, comparable to the time required for a deterministic numerical simulation.

The presented article will describe an 'effect-cause' model for the purpose of simulating the energy consumption of DC fed light rail vehicles. The model will assess the advantages of hybrid vehicles in terms of energy consumption, network power and voltage variations, line current and losses; and will help sizing and designing a supercapacitor based energy storage system (ESS) for both on-board, and stationary applications. The proposed modeling needs to allow the ESS sizing according to the objective that needs to be achieved, being braking energy recovery, voltage drop compensation and peak power shaving the most common goals of ESS use in hybrid vehicles. The needed power and energy levels will vary in function of the vehicle features and the driving cycle followed. This all can be determined by the quasi-static simulation tool to ease the design process. Another objective of the modeling tool is to evaluate the behaviour of the vehicle power flow controller, which manages the power from/to the ESS in function of the state of several variables.

This paper analyzes different policies that may promote the transition to sustainability, with a particular focus on the energy sector. We present a dynamic simulation model where three different strategies for sustainability are identified: reduction in GHG emissions, improvements in energy efficiency and the development of the renewable energy sector. Our aim is to evaluate the dynamics that those strategies may produce in the economy, looking at different performance indicators: rate of growth, unemployment, fiscal position, GHG emission, and transition to renewable energy sources.

Abstract In the field of innovative power sources, photovoltaic are playing an important role as new clean energy generators. The performances being dependent on instantaneous weather condition, photovoltaic sources are usually equipped with an auxiliary energy storage device. There are applications where the opportunity to couple the photovoltaic source with ultracapacitor can be taken into account. The aim of the paper is to study the performances of a hybrid system constituted by photovoltaic and ultracapacitor sources. In particular, the paper deals with the study of the ultracapacitor rate design for photovoltaic systems feeding pulsing loads. The results of the study, which can also be referred to temporary unfavourable weather conditions, have been validated by experimental data. In the final part of the paper, some considerations on economical implications about the dimensioning of a photovoltaic–ultracapacitor systems are drawn.

It has been suggested that the relationship between income and the associated environmental pressure in terms of derived materials inputs and pollution levels may take an inverted-U shape, indicating a 'delinking' of environmental pressure from economic growth in relation to rising per capita incomes. The likelihood of such a relationship being persistent is discussed in the context of a simple macro model of industrial metabolism, and the possibility of 'relinking' clearly emerges. Data on specific indicators of environmental pressure (i.e., the throughput of materials, energy and the volume of transport) in 19 countries have been used to investigate patterns of delinking. The results suggest that delinking may not be persistent; already some advanced economies may be entering a new period of relinking. The relationships between environmental pressure and welfare in the medium long term may be N-shaped rather than inverted-U-shaped.