Abstract

Electric mobility can reduce energy consumption and polluting emissions and is one of the key elements of the current energy transition. Electric vehicles take over is hampered by different problems, above all the scarce diffusion of adequate recharging infrastructures. The objective of this paper is to design a smart system for the shared charging of electric vehicles. Such system minimizes the necessity of additional infrastructure by valorizing the electricity not used by a residential building. The effectiveness of such a system has been demonstrated in two realistic scenarios with a building consisting of 3 apartments and an elevator, a photovoltaic system, and up to 4 electric vehicles.

Abstract

The upcoming transformation from internal combustion vehicles to electric vehicles in the private transport sector, together with the increasing demand for electricity, leads to challenges such as over-loading for the power grid. This study shows an economic analysis to what extent storage systems can be an alternative to conventional grid reinforcement. Current and predicted costs for storage systems are compared with the costs for cable replacement in the medium-voltage grid and correlations are derived. Accurate co-simulations of storage systems and the distribution grid allow these cost scenarios to be applied to use cases. The results show that the energy related costs for storage systems decrease about 38.5 % from 468 $/kWh to 288 $/kWh from 2020 to 2030. This leads to scenarios, mainly in urban distribution grids, where storage systems are an alternative to conventional grid reinforcement.

Abstract

The combustion characteristics of a newly developed Clustered Porous Radiant Burner was investigated. Numerical simulations were performed at different equivalence ratios for a power input of 12.56 kW and the flame movement was analyzed by locating the maximum temperature points. Thermal nonequilibrium model was considered for the energy equations and the combustion was modelled by employing eddy-dissipation model. Surface combustion was reported for equivalence ratio 0.6, while the submerged combustion was obtained for equivalence ratios 0.7 to 0.85. Stable partially submerged combustion was obtained for equivalence ratio of 0.9. The burner was observed to be unstable when operated at an equivalence ratio of above 0.95. Numerically predicted result was in good agreement with the experimental data.

Abstract

As highlighted by the European Union legislation, the building sector is considered crucial in order to achieve the expected objectives in terms of reduction in greenhouse gases emissions to net zero and below. Furthermore, the impact that user’s behavior has on the energy consumption of residential buildings and consequently on well-being and comfort is well documented. In these regards, the application of Building Automation and Control System (BACS) aims at achieving an improvement in the user’s indoor comfort conditions, as well as a significant reduction in energy consumption due to an optimization of its delivery. This study verifies the potentialities of BACS installation to two case studies; a nearly Zero Energy single-family house and an energy retrofitted apartment located in the Northern Italy. In detail, different scenarios were designed, combining different energy consumers’ profiles, and building automation systems configurations. In order to measure the feasibility of the projects, Cost-Benefit Analyses (CBA) were performed, comparing investment cost with energy savings and extra economic benefits. The latter were estimated through a survey in terms of consumers’ willingness to pay for the installation of smart devices in their homes through a contingent valuation in the iterative bidding format.

Abstract

This paper proposed a piezoelectric wind energy harvesting method by vortex induced vibration (VIV) of axial bending vibrations of a flexible cylindrical cantilever shell. In the past decade, wind energy harvesting method by piezoelectric devices had been widely studied for alternative approach to the conventional wind turbines toward supplying power sources for ultra-low power electric devices which will be used for remote monitoring of large-scale structures. However, most of them were based on the combination of a rigid bluff body (BB) cylinder and a cantilever beam which contains piezoelectric element, and had problems of low power generation and durability against repeated loading. In the authors’ previous reports, a new Piezoelectric Cylindrical Shell Wind Energy Harvesting Flag (PCSWEHF) had been proposed as a flexible and durable power generation structure that utilizes VIV and power generation performance by circumferential bending motion of side-supported shell harvester was experimentally verified. In this study, we experimentally investigated the cantilever-type flexible structure based on the PCSWEHF by using prototypes with different parameters: the cross-sectional area of the cylindrical shell is constant, and the outer and inner radii of the shell are varied.

Abstract

This paper proposes a residential peer-to-peer (P2P) energy trading market for prosumers with battery storage systems. To this end, a P2P energy trading mechanism, including the rules for buying and selling energy, is presented. In addition, the supply function bidding method is adopted to match the power supply imbalance and calculate the market-clearing price. Based on the proposed model, a single-objective optimization problem is designed to minimize the total energy cost of all prosumers. To avoid the unfair benefit distribution for market participants, we further put forward a multiobjective optimization problem to solve the issue and reduce the total energy cost as much as possible. The simulation results validate and compare the performance on cost reduction of the proposed two optimization problems.

Abstract

Energy efficiency and environmental performance become important aspects of all transportation branches involving diesel engines as prime movers. The same is for the fishing sector, where besides ensuring sustainability, one seeks for minimizing operative costs through the reduction of fuel consumption. Ship emissions can be determined at different levels of complexity and accuracy, i.e. by analysing ship technical data and assuming its operative profile, or by direct measurements of key parameters and their postprocessing to obtain exact amounts of exhaust gases. This paper deals with the analysis of the environmental footprint of a fishing trawler operating in the Adriatic Sea, including both Well-to-Pump (WTP) and Pump-to-Wake (PTW) phases of the fuel. Based on the data on fuel consumption and exploitation scenarios of the considered ship, provided by the ship-owner, the ship emissions have been determined. Also, a review of different emission reduction technologies has been provided Among various alternatives to diesel enginepowered fishing vessels a hydrogen-powered option is considered, where the obtained results show that hydrogen is rather far from application in the Croatian fishing sector.

Abstract

Due to the intermittence of renewable energy and its large-scale access in the power grid, frequency stability control faces severe challenges. To address this issue, this paper considers gas-thermal inertia in the integrated energy system (IES) to provide frequency response. Due to their similar slow dynamic characteristics, this paper gives detailed explanations on power support characteristics of gas-thermal inertia, based on which presents a new method to provide frequency response in IES. The proposed method is tested in an actual scenario and the advantages of considering gas-thermal inertia are verified.

Abstract

As an energy vector, hydrogen faces bulk storage and transportation challenges due to its low volumetric energy density. Following the footsteps of liquefied natural gas, hydrogen is also liquefied prior to transportation. Liquid nitrogen is usually used as the refrigerant in the precooling cycle; however, alternate candidates are also being studied. Liquid air, which is already drawing attention as a standalone cryogenic energy storage system, is one such candidate as enormous cold energy is available in its regasification phase or the discharge half-cycle. In the present study, liquid air is considered the refrigerant stream in the precooling section of the hydrogen liquefaction process. A well-known commercial simulator Aspen HYSYS® v12.1 is used for this unique concept’s design and performance analysis. Composite curves analysis is performed to analyze the proposed integrated scheme’s performance graphically. The specific energy consumption of 8.52 kWh/kg LH2 has been obtained in the unoptimized base case.

Abstract

The decarbonisation targets of the People’s Republic of China are ambitious, and their achievement relies on large-scale deployment of variable renewable energy sources (VRES), such as wind and solar. High penetration of VRES may lead to balancing problems on the grid, that can be compensated by increasing the shifting flexibility capacity of the system, i.e. installing additional electricity storage. Pumped Hydro Storage (PHS) is the most diffused electricity storage technology at the global level, and the only fully mature solution for long-term electricity storage. China has already the highest PHS capacity installed worldwide, and it is planning to strongly increase it before 2030. The present study, based on the data available from the “Pumped Storage Tracking Tool” of the International Hydropower Association, investigates the potential of technology improvement of the existing and future PHS fleet in China, aiming to the adoption of advanced PHS solutions able to better cope with the task of balancing the VRES production. Furthermore, policy recommendations are elaborated to promote, facilitate and support the adoption of these advanced PHS solutions.